Do modern guitar amp PCBs still look like they were designed in the 1980's? - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2017, 06:32:38 am
content: I went searching for pictures and couldn't find any that looked modern.Lack of competition and innovation perhaps?Mike

author: mtdoc
author_rank: Super Contributor
timestamp: April 19, 2017, 06:41:55 am
content: Quote from: e100 on April 19, 2017, 06:32:38 amI suspect how the PCBlooksis less important to the non-engineer end user than how the amplifiersounds.

author: danmcb
author_rank: Regular Contributor
timestamp: April 19, 2017, 06:48:58 am
content: they are very often single sided boards - for cost I guess - and the tech hasn't moved on much, for the most part, indeed.

author: Zero999
author_rank: Super Contributor
timestamp: April 19, 2017, 07:40:00 am
content: I'd be surprised if guitar amplifiers have changed much since the 1980s. There are still some designs in use from the '50s and 60's.

author: AndyC_772
author_rank: Super Contributor
timestamp: April 19, 2017, 07:41:45 am
content: I've had a little bit of professional involvement here.From what I understand, customers for this type of product have expectations regarding the aesthetics of a PCB, and a subconscious expectation that if it looks "good", then it'll sound good too."Good", in this context, meaning "in line with the customer's expectations of how this type of equipment should look".There's no science here, though. A small PCB made with surface mount components and a ground plane will pick up less noise than one made with through-hole parts on a single sided board. In objective performance terms, it's simply better, but that doesn't mean it's what the customer actually wants.Subjective neatness, and similarity to other products with a good reputation, are really important in this highly conservative part of the industry.

author: langwadt
author_rank: Super Contributor
timestamp: April 19, 2017, 07:58:24 am
content: musicians can be strange bunch, on par with audiophools. If something doesn't look, feels and is preferably made with "vintage" parts and designs it doesn't"sound right"

author: BradC
author_rank: Super Contributor
timestamp: April 19, 2017, 08:19:26 am
content: Most amps don't have their boards exposed and I've never met a guitarist with the slightest concern about anything other than how it sounds at a volume level that makes the sound guy scream "turn that fucking thing down or I'll put a knife through the cone" (which incidentally would turn it into the ideal amp to play any Dave Davies Kinks stuff).In general, amps have a large control surface with more than a few knobs. A large single sided board with everything mounted on it is a crapload cheaper to build than a small dense and clever board with a thousand wires out to the pots, or sub-boards with ribbons between them.Like all good engineering, guitar amps are made as complex and "innovative" as they need to be, and no more. That happens to make them easier to fix and mod, which is a nice aside.

author: CJay
author_rank: Super Contributor
timestamp: April 19, 2017, 08:25:11 am
content: Quote from: AndyC_772 on April 19, 2017, 07:41:45 amWot he said ^^^^I've repaired a good number of guitar amps in the past and have 'rescued' amps that would have been a disgrace to my bin but the owners had some weird almost audiophool attachment to them.I have had clients inspect the PCB (only once or twice) when buying a second hand amp, not because they had a clue about the electronics but because they wanted to see the 'quality'.Most fell into the Nigel Tuffnell 'it goes to eleven' realm.

author: oldway
author_rank: Super Contributor
timestamp: April 19, 2017, 09:07:22 am
content: According to my findings, it is not recommended to use printed circuits boards with tubes for the following reasons:- strong heating of the solders of the socket of the tubes and of the power resistors, which causes bad solders. The situation has worsened since the use of lead-free solder.- high voltages in the circuits, especially in the output tubes .... there is a high risk of arcing and carbonization of the printed circuit.The use of printed circuits boards causes a great reduction in the reliability of the amplifiers.

author: BradC
author_rank: Super Contributor
timestamp: April 19, 2017, 09:15:23 am
content: Quote from: oldway on April 19, 2017, 09:07:22 amSomebody better tell Mesa Boogie they've been doing it wrong all these years!

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: April 19, 2017, 09:20:32 am
content: Quote from: oldway on April 19, 2017, 09:07:22 amThis sounds like typical audiophool-bs to me. PCBs have be used in applications like amplifiers and other devices where components get hot for ages now, with no difficulties. High power amplifiers for stage work/monitors, that push out a lot more power and have to hold up to a lot more abuse, have been using PCBs for a long time.More related examples: I also believe that some of the most "workhorse" guitar amplifiers, like a Mesa Triple Rectifier, or a Peavey 5150, etc, have used PCBs since day 1, and they are said to be among st the most reliable bits of kit out there. Of course, you might put the tubes themselves in sockets connected through wires not just for reliability but for maintenance and aesthetic reasons (so they are easily accessible for replacement and they look nice through the amplifier.)On the arcing topic: You are "only" dealing with <1kV here. PCBs have been used in other applications like CRT drivers, laser drivers, .... That deal with far higher voltages. Especially given the amount of room in guitar amplifiers (they are stupendously huge, often half-empty boxes because they have to "fit" the speaker cabinets they sit on) this seems like a non-issue.

author: filssavi
author_rank: Frequent Contributor
timestamp: April 19, 2017, 09:41:19 am
content: Quote from: oldway on April 19, 2017, 09:07:22 amFirst if you have arcing in a 600V PCB trace (the operating voltage of KT88's is 560V as per datasheet) you might want to fire who layed out said circuit board for his gross incompetenceSecond don't fault PCB for the amp producer greed if they where so concearned with solder thermal cycling issues (which think are non existent in good designs) they would use the more expensive press fit technology

author: oldway
author_rank: Super Contributor
timestamp: April 19, 2017, 10:11:28 am
content: In a push pull configuration, normal peak working voltage can reach twice the operating voltage ....If the amplifier is working with no load, the anode voltage can reach several KV'sI repaired a lot of tube gears with pcb's (amplifiers, b§W and color tv's, scopes, ...) and the first thing to do is to look for bad solders at the tube sockets....In tube amplifiers, whe never relied upon solders to ensure contact between the socket and the components.One of the first rule was to ensure contact by mechanical fixing ....Faylon Studio 40W

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 19, 2017, 10:22:57 am
content: https://www.thegearpage.net/board/index.php?threads/the-amp-guts-appreciation-thread.334977/

author: danmcb
author_rank: Regular Contributor
timestamp: April 19, 2017, 10:42:55 am
content: somebody explain to me how a TV can have 20kV on a circuit board with no arcing, but a guitar amp has problems at 250V.There are a few exceptions. Vox have a line of amps with some really good digital modelling for all kinds of classic vintage amps (with subtly changed names) and they sound really good, at least to me. Also there is a company (Marshall spinoff I think) that do some really neat stuff. I forgot the name.but yes, it is a really stupidly conservative industry. I have experienced this first hand.

author: cowana
author_rank: Frequent Contributor
timestamp: April 19, 2017, 10:51:20 am
content: Quote from: danmcb on April 19, 2017, 10:42:55 amA slight generalisation, but in most TVs the 20kV never goes near the PCB. The HV is generated by a flyback transformer, which outputs the HV directly into a heavily insulated lead connecting the flyback transformer to the CRT.

author: Fungus
author_rank: Super Contributor
timestamp: April 19, 2017, 11:04:18 am
content: Quote from: oldway on April 19, 2017, 09:07:22 amThe amps on this page don't have the tubes on the PCB, they're on a metal bracket with wires going to the PCB.https://www.thegearpage.net/board/index.php?threads/the-amp-guts-appreciation-thread.334977/Quote from: oldway on April 19, 2017, 09:07:22 amWeird how nobody is seeing any. I guess the "risk" isn't so high after all.Quote from: oldway on April 19, 2017, 09:07:22 amSo why are they still using designs from the 1960s?

author: Fungus
author_rank: Super Contributor
timestamp: April 19, 2017, 11:09:28 am
content: Quote from: BradC on April 19, 2017, 08:19:26 amI'm sure this is a big part of it. Replacing capacitors, etc., has been a thing among audiophools for decades.Also: Valves and oversized components look the part!There's no way surface mount on a tiny PCB could ever produce a decent sound. The electrons will be strangled.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: April 19, 2017, 11:17:26 am
content: Quote from: Fungus on April 19, 2017, 11:09:28 am"Strangler", do they make that guitar pedal? If they don't they should.

author: oldway
author_rank: Super Contributor
timestamp: April 19, 2017, 12:05:13 pm
content: The appreciation of the quality of a sound is something very subjective and soms very strange.In my opinion and that of several of my friends, it is not the most perfect amplifier that sounds the best ....This old ARTEC tube Hi Fi stereo amplifier of the 60s sounds better than my Marantz 2285B....And yet, This ARTEC has a measured THD of 3%...

author: oldway
author_rank: Super Contributor
timestamp: April 19, 2017, 12:06:41 pm
content: And no pcb at all....

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2017, 12:34:49 pm
content: Quote from: frozenfrogz on April 19, 2017, 10:22:57 amThe components on those boards look like they are deliberately hanging in the breeze to achieve maximum microphonic pickup. Is that the secret sauce that makes a 'classic' sounding amp?

author: oldway
author_rank: Super Contributor
timestamp: April 19, 2017, 12:46:58 pm
content: Quote from: e100 on April 19, 2017, 12:34:49 pmGreatest concern with microphonic pickup is with low level signal preamplifier tubes.Even using special low microphonic tubes as EF86, I often had to select the best of themI have never had problems of microphonic pickup with other components.

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2017, 01:01:11 pm
content: Quote from: AndyC_772 on April 19, 2017, 07:41:45 amHow about a placebo PCB that looks like something from the 60's or 70's but is actually non functional. Hidden under one of the electrolytics would be a single DSP doing everything except the PA stage. Could knock a few dollars off the BOM. Target the low end of the market first. There could even be a viewing window with mood lighting like they do with gaming PCs.

author: AndyC_772
author_rank: Super Contributor
timestamp: April 19, 2017, 01:14:06 pm
content: No. Never treat your customers like idiots.

author: b_force
author_rank: Super Contributor
timestamp: April 19, 2017, 01:21:37 pm
content: Have been in this field for many years.It's absolutely NOT about lack of 'competition and innovation'.The competition is very strong in the music industry.It's is mostly just about marketing.Although, things are shifting quite a lot lately, for most guitar players, the better amp is still hard-wired and all tube/valve.From a technical point of view that's obviously a little bizarre of course (much more noise, more expensive to make, more defects and repairs etc).Besides there are some main (well known) big brands, that just like to stay 'old fashioned'.I think mainly because they don't need to spend money into research and development and don't have to run the risk of developing a new complete failure.Keep in mind that naturally most companies don't want to risk to much, and therefore like to close up the market as much as possible.In fact, the guitar itself has barely evolved from the last 50-100 years.But like I said, the market is shifting.5-10 years back 'digital effects and amplifiers' were a complete taboo.Nowadays, every brand has his own set of digital effect pedals, loop-pedals and there are even a lot of new smaller guitar amplifiers.I talk to retailers and shop owners on a regular basis and they all say that people simply don't want a big heavy 50-100W all tube amplifier anymore.To much hassle, to expensive, to many problems with repairs etc.You can even find a ton of reviews on youtube that are actually very positive about all the new innovations.Even in blind tests it is pretty much impossible to hear differences.One of the most well known innovative brands is Line 6, but also Vox has some new products, as well as Yamaha and Blackstar.Although Line 6 is only the one who is serving the high-end market.If you want state of the art, Kemper is pretty lonely at the top.Also every (known) brand has his small little series of transistor/digital effects based amplifiersAnyway, the shifting is actually so big (and all of a sudden) that I sometimes wonder if they are trying to push valves/tubes obsolete in a couple of yearsIt wouldn't surprise me, because the efficiency of tube amplifiers is pretty bad, plus they need a lot of copper (= transformers).One for the mains, one as a choke and one for the output transformer.As far as I know, there is not one brand that is using a SMPS or similar.Which also doesn't go well with all the (new) regulations and rules in electronics, safety, PFC, power supplies etc.So, to summarize; yes there are enough brand/products that use 'nicely' made dual or even 4 layer PCBs.But most of it is still old fashioned, because it simply sells better (because people think it is better)

author: b_force
author_rank: Super Contributor
timestamp: April 19, 2017, 01:28:03 pm
content: Quote from: AndyC_772 on April 19, 2017, 07:41:45 amThis also works for the whole hifi market.I have been studying it for many years now, and companies put a lot of money, energy and resources in getting better THD+N results and other theoretical specs.Why? Well, it is easy stuff to sell to the unknown and ignorant customer.In fact, the stories are so deeply penetrated that even a lot of (very highly respected) engineers believe in these fairy tails and marketing BS.On the priority list, these things are aaaaaallll the way at the bottom.But once a good gossip marketing story has settled, and big well known respected companies use them, it is VERY difficult to get rid of them.(impossible)

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2017, 01:41:32 pm
content: I did a Google search for "guitar amp DSP" naively thinking it would turn up a bunch of results, but it turned up almost nothing until I stumbled upon the term "modeling amp" which is an amp containing a DSP that allows it to emulate the sound of other types of amps. So it seems than even the word 'digital' is taboo in the guitar world.

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2017, 02:08:44 pm
content: Quote from: b_force on April 19, 2017, 01:21:37 pmSo the marketers have been promoting the old designs for for the last 20+ years in order to protect their profit margins?Wouldn't be the first time that music industry has dragged it's feet in the face of new technology.I suppose it's the power of the cartel controlling the market, making sure any new players "don't rock the boat, don't tip the boat over", so to speak.

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2017, 02:31:40 pm
content: Found a picture of a modeling amp interior complete with switch mode power supply.Fromhttp://www.kramerforum.com/george/amps.html

author: b_force
author_rank: Super Contributor
timestamp: April 19, 2017, 02:47:10 pm
content: Quote from: e100 on April 19, 2017, 02:08:44 pmWell, of course it's a bit of an chicken - egg story.But does this sounds new to you? I mean in all markets companies make you believe in fancy stories.The whole music industry is one big niche filled with voodoo for example.I can give you thousands of products that are being sold for $$$, are badly designed and are praised by many (even technical engineers).This is just called marketing. Once you get the hang of it, open your mind with a skeptic point of view, you will laugh your pants off.Dive in the world of test equipment and it is the same story.Digital is indeed a bad name in the music industry.For the same reason as Class-D amplifiers had a bad name (that has already changed)A few companies tried it 20 odd years ago, but the world wasn't ready yet (also because technology wasn't far enough).But that's no different for tablets for example, which you could also find 20 years ago.Microwaves boomed 20 years later after they were invented.Sure the technology wasn't right for it, but people also find it a strange idea to use these products.edit:Maybe to explain something more about marketing.I worked for a company developing big high power Class-D power amplifiers and DSP boards integrated with active loudspeakers.One of the problems we had, is how to market our products. aka; what makes our products different and better than other competitors?I am talking about big players on the market (sales over more than hundreds of thousands to millions a year) vs a small company (in tens of thousand).Just saying that your product simply 'sounds better' isn't enough. Especially if you ALSO use a DSP and Class-D amplifiers and competing against big respected companies (even if they are doing it wrong for years)For that reasons the company was still making a lot of 'analog-filters'. Simply because customers (and oddly enough some engineers) believed in the fact analog is better (less noisy etc etc) than digital.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 19, 2017, 02:54:30 pm
content: Digital is not really a taboo, but it heavily depends on what you genre of music you are looking at.There are two major competitors in the field of DSP / modeling amp / virtual amp setup. One is Fractal Audio with the Axe FX line and the other one Kemper with their Profiling Amp.Line6 (POD, Helix,...) are a bit on the cheap side and though they improved in tone quality, I would classify them as second league.There are some Hybrids, like the Peavey Vypyr series and Hughes&Kettner Coreblade / Switchblade.If you need versatility in a band that travels a lot, Fractal and Kemper are a good solution. You can even go the full mile and just pack your sound setup on USB drive with you. On stage, you get gear from the distributor, drop your sound setup in and are ready to go (H&K Coreblade also can do that).Most musicians are gearfreaks – as some of you can relate to – so you might own a bunch of amps, effect pedals and what not. In the past five to ten years, guitar tube amps have lived through a revival, mainly in the so called "High Gain" sector. You can get a lot of boutique amps and of course the big manufacturers try to get their share.Basically, you are correct: It is the 80s all over again. If you want to be »Metal« you want to play a heavy, oversized head amplifier with two 4x12’’ speaker cabinets.From a sound studio perspective I can tell you: DSP has come a long way, but in direct comparison to the "real deal" you don’t get the same response from a modeling amp compared to a good tube preamp section.Now a little for your call to old-school PCBs: There is a lot of space inside a typical tube amp housing. So why go all fancy with four-layer high density boards, when you really don’t need it, plus you are dealing with big fat parts anyway? (caps, tubes, transformers, high power resistors,...) From a modding perspective it is even greater value. You don’t have to fuck around with dense integration, but you can simply work on clean subsections. Input section here, tonestack over there, some inverting magic on that end, FX loop that way, power amp section here and power supply on that board...

author: b_force
author_rank: Super Contributor
timestamp: April 19, 2017, 03:04:23 pm
content: Quote from: frozenfrogz on April 19, 2017, 02:54:30 pmYes, this is in line with my research as I mentioned above.Using DSP's is also a little bit digging your own grave.I mean, as soon people know that you can make EVERY amp with the same design (which can easily be done with DSPs), why would they even buy new equipment? In fact, with impulse responses and some eqing you can make your guitar sound like any guitar you like.So companies NEED to make up a story to sell new stuff, therefor they don't mind keeping up the voodoo stories.This has been the issue for a very long time for light bulbs.For that reasons companies (like for televisions) obviously design with parts with underrated specs.

author: free_electron
author_rank: Super Contributor
timestamp: April 19, 2017, 03:11:12 pm
content: Quote from: oldway on April 19, 2017, 09:07:22 amtubes ? it is 2017 ! time to bury that 'glass with scrap metal in it'.

author: Cerebus
author_rank: Super Contributor
timestamp: April 19, 2017, 03:25:16 pm
content: Quote from: AndyC_772 on April 19, 2017, 01:14:06 pmUnless they are drummers.Cue long thread of drummer jokes...

author: drussell
author_rank: Super Contributor
timestamp: April 19, 2017, 03:26:31 pm
content: Some people who are not in the industry do not seem to realize that thewhole apparatus from the guitar string to the pickup to the way the particular guitar body and neck vibrates to the cabling and any in-line effects pedals to the pre-amp stage to the tone controls to the output amplifier to the speakers and the cabinet they are in...THAT WHOLE THING... becomes the "instrument".The whole package defines what kind of "sound" the player gets, so,YESall of these things matter!! This includes any distortion, feedback, microphonics, etc. that, while they would generally be highly undesirable in a Hi-Fi amplifier, arecriticalto achieving the "sound" that particular musician wants and is probably "known for".There is a damn good reason that people will spend a small fortune keeping what seems like some old clunker to the casual observer running asthey want itregardless of if it is "correct" or even anywhere near what the factory originally intended, etc.It istheirsound!

author: drussell
author_rank: Super Contributor
timestamp: April 19, 2017, 03:28:09 pm
content: Quote from: Cerebus link=topic=86956.msg1189153#msg1189153All the drummers ever seem to say is, "I need more kick drum in my monitor!"

author: drussell
author_rank: Super Contributor
timestamp: April 19, 2017, 04:07:18 pm
content: Quote from: free_electron on April 19, 2017, 03:11:12 pmSpoken like atruenon-believer!Are you qualified to comment on this? Do you even own any tube gear?You stick to your crunchy, crufty, crudular solid-state gear, and I'll happily plod along listening to my music on my Dynaco Mk. VI monoblocks with the 8417s playing through good home-made speakers, thank you very much!The sound can be absolutely euphoric!(Though, I must admit, my old Bryston 4B is pretty good too... For a SS amp!The warranty on that ol' bird is even finally well past expired, despite the fact that Bryston retroactively increased the warranty duration to 20 years from the original 15 years.)

author: N2IXK
author_rank: Frequent Contributor
timestamp: April 19, 2017, 04:17:27 pm
content: Quote from: drussell on April 19, 2017, 04:07:18 pmThe only question is where are you finding 8417 tubes these days at a price that doesn't call for a second mortgage? The Russians and Chinese haven't been able to produce those today, despite several attempts.

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2017, 04:21:53 pm
content: Quote from: AndyC_772 on April 19, 2017, 01:14:06 pmWell I just found a modeling amp (aka DSP powered amp) that has valves to give it that authentic sound that a DSP simply cannot provide (apparently).https://www.sweetwater.com/store/detail/AV30Combo

author: LaserSteve
author_rank: Super Contributor
timestamp: April 19, 2017, 04:24:07 pm
content: At our church we had a guitarist who insisted that if the plate in the tube is not glowing red, he did get "his" correct sound. So one day I snuck in early and replaced the preamp and power amp tubes on his stupid little 100$ box. The power tube was so gassy you could see the plasma in room light. There was a master gain / bias pot inside the amp, and that got set down to something more reasonable. Both old tubes were immediately sent to fire bottle Heaven using a humane hammer.That was the day he learned he could play classical guitar and sound much, much better. The smile on his face grew the more he played that day.It's also the day we sent him to ear specialist to save what was left of his hearing.Moral of the story, since their teens, musicians are often taught this audiophool lore about what they should do. They really didn't want me to put wall treatments and Bass corner damping in the band area. Now that they can hear each other, and are not getting lobes from the monitors , they won't play without the adsorber panels, and are asking for more.It comes down to education, and having a congregation that backs me when I make changes. Our measured C weighted sound level is down 20 Db at the back of the church from when I started, our voice intelligibility is way up, and we get compliments on how the band sounds now.We simply didn't tell them when the DSP amps went in and the snakes were replaced with 30 pairs of double shielded wire under the floor. Our noise floor went down to below what I can measure, and no more 60 Hz hum. Getting all the sound and video gear on the same line phase helped too. You can't "buck" hum when it's 120' out of phase.But some times I still feel I will need to open the "Stalog 440 " re-education camp, to remove the folklore and marketing BS I have to deal with ofhim.But you can reform them with patience and a big enough stick.Steve

author: b_force
author_rank: Super Contributor
timestamp: April 19, 2017, 04:32:14 pm
content: Quote from: drussell on April 19, 2017, 03:26:31 pmNo, it's all about THEIR feeling.You can make a 100% identical sounding and technical measuring amp with just a DSP and a (simple) class-d output stage.In fact, technically it's not that difficult to cancel/correct all these links in the chain and even the most advanced and experienced professionals in the field are unable to hear the difference.There is more than enough literature about this.Most technical people forget something and that is that most people (inlc engineers) don't choice rationally.So if things don't feel right, it simply doesn't work for them.This whole phenomenon is called placebo effect.We simply hear, feel, see, taste and believe things that are not there.Perfect grey area for the marketing department to make up some juicy stories.Quote from: LaserSteve on April 19, 2017, 04:24:07 pmThis is exactly what I was talking about.As soon as people don't see it anymore, things turn out very different.That's why double blind tests are so important.Once read a paper about a double blind test between a very expensive Stradivarius and a decent priced Yamaha violin.Guess which one people liked better?Like I said before, the problem is when even engineers don't know what is real anymore.And yes, I have come across many 'guru's' who now simply believe in their own marketing BS crap.

author: Zero999
author_rank: Super Contributor
timestamp: April 19, 2017, 05:02:25 pm
content: Quote from: frozenfrogz on April 19, 2017, 02:54:30 pmLet me guess. If you're into electronic dance, contemporary R&B, hip-hop etc. then you're more likely to be a digital lover, than someone who likes blues, country, rock etc.Then they're the music snobs also annoy me. They'll only listen to a few genres or hate anything too pop because it's not real music.Personally I don't care. I can be picky but I listen to various types of music.As far as amplifiers are concerned: if modern technology can emulate old valve amps then great but I see no reason not to build and use them because old things are cool. Some people still enjoy building and using steam engines, even though they're well and truly obsolete.

author: danmcb
author_rank: Regular Contributor
timestamp: April 19, 2017, 07:22:53 pm
content: A year or two back, I designed a nice analogue preamp/compressor/overdrive/distortion box that I intended to be a bit better than the usual diecast box with a 9V supply and so on. I spent quite some time on it - a nice optical compressor, silent switching, and running internally from +/-15V so it has much more headroom and signal/noise than most of these things. Also a decent quality properly designed metal case (which cost me a small fortune in low quantity.) I went through quite a few prototype/test cycles with various musician friends (I know a bunch as I also play a lot).I took it to the local guitar boutique store, and showed it to the guys there. The Axeman-in-chief looked at it sceptically and asked why it was so big, used a funny power supply, etc. After telling me how there was so much on the market and really no need for anything more, he decided to actually try it out.He plugged it into a nice looking Fender valve amp, played for ten seconds and then said to me "I see what you mean". (I must admit - it did sound good - and he could play.)Ten minutes later, he went to his boss, pointed at my box, and said "this thing is dynamite" (or words to that effect). So they took one on sale or return.I went back a few weeks later, it was in a glass case, next to a huge, garish pink and blue thing with more lights than Blackpool 9my box is simple black and white - has some nice LEDs for level setting, compression and so on - but looks pretty dark with power off). I asked then how it was going. They said "disappointing - noone asks to try it".I didn't ask them if they actually suggested it or actively tried to sell it to potential customers. I think I know the answer.I have sold a few - one is being used in the live rig of one of the top session players here (we made a deal where I discounted and he made me a great video), another is in one of the top studios (apparently it was used the first weekend they had it - by a guy that produced some Blur albums. On bass.)It's all about marketing, as others have said. Most people will buy what looks cool or what a magazine/website tells them is cool. Unless a thing sounds *really* bad (so bad that you'd actually have to try to get it that way) very many will not even hear any difference.But - the really good ones - *do* know the difference, and hear it. But that is about 0.2% of people. Most of the market is composed of amateur or semi-amateur musicians who very often put up with pretty poor quality, and don't notice it.

author: james_s
author_rank: Super Contributor
timestamp: April 19, 2017, 07:28:43 pm
content: Quote from: CJay on April 19, 2017, 08:25:11 amHah! That's a great movie, haven't seen it in a while.

author: Jr460
author_rank: Regular Contributor
timestamp: April 19, 2017, 11:03:36 pm
content: Yes there are many idiots on stage that have all kinds of strange ideas about amps and sound.Me, I 've either played in a band (keys, bass, vocals) or ran sound for one of the past 40 years.One guitarist I worked with had this 100 watt Fender transistor amp. I sounded OK if you got the thing turned up to about 7 or 8. But in small clubs 2 or 2.5 was killing everyone. He never got the idea to get something smaller and then you can crank that and let the PA fill the room. He would read all the wrong things.... "Hey, we have that festival next week, I've heard you should use, or use more compression when playing outside. What do you think?" I told him he was nuts, stop reading the 14 year old Stratplay452 on some guitar forum and get a sound he likes and let the PA take care of the rest. He never got it. Set his amp back by the drummer. The drummer proceeds to bash the living hell out of the brass to hear himself over that monster amp. Turn into loudness war.My keys have been mainly digital, but I have to say it is a lot of fun to play a real B3.... each one has a slightly different personality.The current PA rig I drag out is a digital board, (not a bear-ringer or smackie), and I love the way it sounds and so does everyone that has heard it and A/D converters. Speakers, I've done both QSC amps into passive speakers, but recently all-in-one powered tops and subs that are class D and DSP driven.The current band I run FOH for, the guitarist used a Line6 amp for a long time and it was OK. It had some fault where the volume would jump up or down without warning. He researched it fund it to be a common fault and the only fix is an expensive replacement of the one and only board in it. A few weeks ago he picked up a small newish Vox tube amp and drove it with a Fender all-in-one pedal board.Yikes!!!!Total nightmare. Sounded like ass. It just would not do what he wanted when he wanted it. One the first break, he pulled the Fender and plugged in a set of foot pedals. It was much better, but now he was gun shy the rest of the night, paying more attention to his tools than his work. He had 30 days to return that amp and he did and picked up a 10 watt tube amp instead.Last weekend was great. He never sounded so good. It allowed him to put his effort into playing, not playing with gear. About the only thing better that I've heard is the wife's guitar into AC30 clone I build for her. I might be a bit biased.I'm don't dislike digital, I don't bow down to tubes either, but the current DSPs don't sound the same. Close, very close, but different.One other thing to keep in mind. The older designed amps with point to point wiring and such can take a lot of road abuse. You would be surprised how much everything gets torn up even with just weekend gigs.

author: e100
author_rank: Frequent Contributor
timestamp: April 20, 2017, 03:23:06 am
content: Quote from: b_force on April 19, 2017, 01:21:37 pmSo the marketing people are actually responding to the consumer demands for lightweight easy to transport gear?Why now and not 10 years ago?Has another manufacturer managed to disrupt the market forcing the cartel to move in lock step?When I started this thread I had no idea we would end up here. It has been a fascinating window into the power of marketing and it's ability to stifle technology for an entire generation.

author: WZOLL
author_rank: Regular Contributor
timestamp: April 20, 2017, 03:57:15 am
content: As far as I know the only amp that cant be completely modeled by a DSP is the Deacy amp because of its damaged cone. IMO complex modular analog synths are the only thing that can't be reproduced digitally 100%. Here is the amp in action

author: BradC
author_rank: Super Contributor
timestamp: April 20, 2017, 04:03:36 am
content: Quote from: Jr460 on April 19, 2017, 11:03:36 pmThis is the thing. I gigged for years with a transistor amp and a variety of "modelers" to give me a Vox AC15 jangle. They did a credible job, but were never quite right. Close though. I was pretty happy with the sound until I did a gig with a borrowed AC15. My problem here is I can't figure out how to express exactly what I want to say, but there is no way in hell the modelers even get close to replicating the "responsiveness" of the real thing. The best way I can describe it is the sound itself is close, but the way the sound changes in response to playing volume. Attack on the string I suppose is the best way of describing it. It's just nowhere near it. It's almost like the amp has more dynamic range, but it'd better be described as characteristic non-linearity that the modelers just don't get right.I've owned mostly solid state amps since I've been playing and I've used most modelers at least once. I'm a firm believer in technology and the constant improvement it can bring, but I've never found a solid state amp that can get close to the sound of a valve amp if that is the sound you are after. They are all "close but no cigar". And don't get me wrong, having the ability to go from a jangly Vox to a Marshall scream and a Fender clean at the twist of a knob or press of a pedal is fantastic. But there is still a significant difference, and the fact it's so hard to explain and quantify is why none of the modelers are there yet.It's not Audiophoolery, there is a credible difference in the end to end signal chain when you plug a guitar into a valve amp. Then put an old Echomatic in the chain and see it change again. The non-linear pre-amps and asymmetrical valve biasing leading to an asymmetrical load impedance for the wound pickup combined with the variable capacitance of the various guitar leads. It's a pretty complex chain to try and model.Remembering that even the wood the speaker box is made out of forms part of the "instrument", and then try and figure out how to model that entire chain.I love my bulletproof transistor amps and digital modelers, but when you want that special sound that nothing yet replicates, you need warm bottles of almost-vacuum. Nobody has yet perfectly replicated the chaos of non-linearity they present. Maybe it's "personality"

author: bibz
author_rank: Contributor
timestamp: April 20, 2017, 04:32:38 am
content: This is a far too nuanced and experience related topic to really go into detail here. The pcb isn't the 'guts' of an amp. It's not the main focus like it is with digital stuff. To me the tubes (different brands sound and react different, pick a single type and spec of transistor for every different project...you can't!) and the transformers will play just as big a role as the circuit. But thats just the high end stuff. Theres plenty of SHARc and whatever based stuff, the AxeFX and particularly the Kemper profiling stuff is VERY deep in technology. It's software stuff would be a very heady read.But in the flesh, the feel counts more. You can't pick a wife from a datasheetIt's all relative, you can get by with an irig setup and some headphones. Sounds 'ok' at times. Different experience. I use software for practicing, its instant gratification, but it in no way can replicate real gear at real volumes. If you've never felt what its like pushing major air around a big room at your will with a big guitar sound I can't describe it for you

author: razberik
author_rank: Frequent Contributor
timestamp: April 20, 2017, 07:56:19 am
content: Reminds me the era when Fractal Axe-FX was released. So much hatred from tube amps owners. I understand them. If I spend million for tube gear and then it can be replaced by one box with unlimited performance for 1/10 the price I wouldn't be happy too.I have to admit I discovered 1/2 year ago that Marshall JMP-1's tubes are useless and do pretty much nothing in the signal chain.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 20, 2017, 08:38:25 am
content: In the studio, we do not care much about looks – it is all about the sound.Yes, the Kemper and the Fractal both are good in what they are doing and for a live setup, they are great.However, transient response, harmonic break up,... of the modeled / profiled amp is not the same when compared to let’s say a hardware built Peavey 5150. We have the 5150, 5150 II, 3120, XXX next to each other and all of them have very unique characteristics although they are basically built in a very similar way and feature more or less the same parts. And that is just comparing them on the closest-to-each-other sound settings you can dial in, through the same cabinet, with the same guitar, same microphone and same microphone placement.The profiled sound of a Kemper is very close to what you get from the amp you used to make the profile of and it is a pretty rad feature to be able to "steal" a certain sound.On the other hand, as stated before by b_force: Music is about feeling.At least what’s on the market today does not give the same response as using "the real deal". It is a little like saying: Who the hell needs a physical calculator, a multimeter and an oscilloscope? I can do it all on my multi-purpose touchpad device. (Yes, apples’n’oranges I know...)BradC described it very good in my opinion as non-linear interaction of all components.

author: oldway
author_rank: Super Contributor
timestamp: April 20, 2017, 09:31:06 am
content: There is a technical caracteristic that can explain why tubes et transistors amplifiers sound differently: the damping factor.Damping factor is an indication of how well the amplifier will control the motion of the woofer driver. Tube amplifiers tend to have low damping factors (8-15), while solid state amplifiers have damping factors (40-90) or even higher.http://eaw.com/docs/6_Technical_Information/StudyHall_and_TechNotes/Damping_factor.pdf

author: BradC
author_rank: Super Contributor
timestamp: April 20, 2017, 09:41:47 am
content: Quote from: oldway on April 20, 2017, 09:31:06 amThat is one of many small irregularities that the proponents of modeling say they can faithfully reproduce. I had a Fender Pro 185 for a lot of years. That was a transistor amp that was specifically designed to have a low damping factor to attempt to reproduce part of that "sound". Don't get me wrong, it was a spectacular amp and capable of making quite a beautiful racket, but it sounded _nothing_ like a valve amp. It had the most beautiful crystal clear sound and was perfect for Jazz or 60's instrumental stuff, but it sounded _nothing_ like a valve amp (yes, I know I said that twice). I think I still have the circuit around somewhere.

author: danmcb
author_rank: Regular Contributor
timestamp: April 20, 2017, 09:45:18 am
content: does that "lack of control" of the speaker come from the output transformer? there are such things as valve amps with direct drive. Wonder how they sound.Also of course there is the slightly asymmetrical distortion and compression-like artefcats that valves produce.

author: b_force
author_rank: Super Contributor
timestamp: April 20, 2017, 11:12:06 am
content: Quote from: e100 on April 20, 2017, 03:23:06 amI know i am not gonna make friends by saying this, but marketing should be part of every engineering study!Why now and not 10 years ago? That is the same question for microwaves. If i recall well, they were invented somewhere in the 70s. Nobody wanted it, they just find it weird to 'nuke' your food in a machine. Nowadays, it's standard in every kitchen.On the other hand companies and manufactures have proven they can make good sounding 'digital' amps and effects. It also goes completely in line with the more sustainable 'green' thoughts that are hip nowadays (at least in europe).Like i said, and i am absolutely not sure about this, but they can't go on like this. The guitar market already has seen some new changes in useing certain types of wood lately. I personally just find it difficult to believe that they can keep using big transformers and current sucking tubes.It's interesting that there has been virtually no improvements in these amplifiers and tubes at all.Except for the Korg-NuTube.I have seen someone modelling tubes with just some fets (and a lot of extra passives and diodes) and it sounded (and measured) the same.Btw, with all the respect, but I didn't expect certain reactions here on an electronics/engineering/science forum.The fact that there isn't 'anything like it' or 'doesn't sound like it', doesn't mean it can't be done!!I have seen and done blind tests between a few differences, and there is absolutely not a single human being that can hear the differences.'Damping factor' (marketing name for just saying output impedance btw), can perfectly being modeled in a DSP. Same goes for the harmonic footprint/content.From a scientific point of view, the only conclusion can be; placebo. But placebo has been a taboo word, even in the medical field.

author: b_force
author_rank: Super Contributor
timestamp: April 20, 2017, 11:20:24 am
content: Quote from: frozenfrogz on April 19, 2017, 02:54:30 pmI agree. But there is one big difference.Most people don't really care about what engine they use (in their car for example). But for some reason most people get all worked up if it's about music and audio.My only guess is that it's because there is emotion involved. Listening and making music is an emotional experience.For that reason it's more difficult for people to except 'changes'. Nostalgia is a big (and valueable) thing in music (good memories with)Also, companies make you believe in voodoo stories, becauses it's better for their sales.

author: Fungus
author_rank: Super Contributor
timestamp: April 20, 2017, 11:25:57 am
content: Quote from: oldway on April 19, 2017, 12:05:13 pmMaybe the ARTEC got lucky. There's other factors at play here - your speakers, your room, your choice of music, etc.eg. Your room might be adding a distortion/echo that the ARTEC isn't capable of triggering. Removing that distortion makes it sound "better". You might be able to eliminate it by moving the speakers or adding acoustic panels, in which case the Marantz will sound better.The closer you get to perfection, the more you hear all the tiny defects.(this is similar to the "uncanny valley" in the world of robotics/CGI - sometimes it's better to be a little bit imperfect)

author: Fungus
author_rank: Super Contributor
timestamp: April 20, 2017, 11:31:12 am
content: Quote from: oldway on April 20, 2017, 09:31:06 amInteresting.

author: oldway
author_rank: Super Contributor
timestamp: April 20, 2017, 02:13:08 pm
content: Quote from: Fungus on April 20, 2017, 11:25:57 amI was comparing the ARTEC with the Marantz 2285B in exactly the same conditions, same room, same loudspeakers, same music, ....I wonder how an amplifier could be capable of "triggering" distorsion/echo.....

author: b_force
author_rank: Super Contributor
timestamp: April 20, 2017, 02:17:52 pm
content: Quote from: oldway on April 20, 2017, 02:13:08 pmThe only proper test is a double blind test.Besides you have to confirm (measure) the difference in the amps.And yes, imperfections doesn't always mean it's bad. But it depends on taste of course.

author: danmcb
author_rank: Regular Contributor
timestamp: April 20, 2017, 03:11:36 pm
content: it's true that the most *honest* amp isn't always the one that sounds the *nicest*. Of course - depending on the listener, room, material, moment ... and so on.And yes double blinds are the only way to go really - but so difficult to do right, it is very rarely done. So, instead we have a whole sub-species of "hi fi reviewers" whose words often sound more like those of wine tasters ... such is life.

author: james_s
author_rank: Super Contributor
timestamp: April 20, 2017, 06:32:14 pm
content: Quote from: b_force on April 20, 2017, 11:20:24 amI think they do. I would guess there are at least as many people who are passionate about the engine in their car as about the guts of their guitar amplifier. People have passionately debated Ford vs Chevy, etc for as long as there have been multiple brands of cars. To someone who just wants to get from point A to point B they probably don't care. Ford, Chevy, Toyota, Honda, whatever, pretty much any modern car will get you around and run for many years with reasonable care, that doesn't stop people from being passionate.When it comes to music, it's a very subjective matter. One amp may be technically superior to another in every measurable sense, but that doesn't mean it will sound better to the artist who is going for a specific sound. Doesn't mean the placebo effect doesn't play a huge part in it either but who cares? If someone likes the way a certain amp sounds or looks what does it matter to me?

author: danmcb
author_rank: Regular Contributor
timestamp: April 20, 2017, 06:38:31 pm
content: -- well worth your time if you are interested in this subject.

author: Jr460
author_rank: Regular Contributor
timestamp: April 20, 2017, 10:46:59 pm
content: Quote from: danmcb on April 20, 2017, 06:38:31 pmEthan..... Oh my. No problem with some of things he says, but some of his video and writing borders on nutty. Check some recording forums where he tried to argue with people. It was not pretty.In terms psycho-acoutics, JJ is really knows what he is talking about.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: April 21, 2017, 12:12:42 am
content: Look inside a KemperEDIT: didn't see it was more than one page...

author: jh15
author_rank: Frequent Contributor
timestamp: April 21, 2017, 04:34:19 am
content: No talk of guitar amp output transformer saturating being the electric guitar sound in the beginning?And as others said, the amp is part of your guitar sound, warts and all.

author: BradC
author_rank: Super Contributor
timestamp: April 21, 2017, 05:10:51 am
content: Quote from: jh15 on April 21, 2017, 04:34:19 amNo point. The Engineers tell us that we're imagining it and it can be accurately reproduced digitally, even against the direct experience of musicians, recording engineers and even musicians who happen to be engineers.I'm sure at some point it *will* be able to be accurately reproduced digitally. It just hasn't happened yet.I'd *love* it to be true. I'd love nothing more than carrying a modeling box and class D amp into a gig. It'd save a world of pain. I have no sentimental attachment to my glowing glass, I've just not found anything better yet (and I've been looking and trialing hard for 25+ years).

author: orin
author_rank: Frequent Contributor
timestamp: April 21, 2017, 06:30:46 am
content: Funny thing was I was watching these last night before I saw this thread... The test in the second video was better in that they could switch back and forth immediately between the real amp and a Kemper. They failed miserably at telling the two apart/guessing which was which. There was some justified criticism that the levels weren't the same at times, but even so...

author: danmcb
author_rank: Regular Contributor
timestamp: April 21, 2017, 06:44:57 am
content: Ethan is very pragmatic, and practical. He very often does actual experimental work and tries to figure out what is and what is not important, and if he sometimes goes off on a wrong one in pursuit of that, I don't have a problem. I like very much the fact that he is prepared to ask the question, instead of taking things at face value because someone told him so. And he often talks a lot of sense.JJ is one of the guys who originally came up with mp3 format, apparently. He was the first person ever to explain fundamentals of DSP to me in a way that actually made sense. Super smart guy, that's for sure.

author: e100
author_rank: Frequent Contributor
timestamp: April 21, 2017, 08:42:35 am
content: Quote from: orin on April 21, 2017, 06:30:46 amSo in summary, under near ideal test conditions they found it nigh impossible to tell the difference.As one of the guys said, what's more important is that one UKP 1600 amp can be made to sound like any other amp, therefore a seller only needs to stock one amp from one manufacturer instead of having a warehouse full of a dozen different models from a dozen different manufacturers. That's why the cartel has been afraid of change.I sense an impending consolidation of the market with only a couple of big companies surviving long term.Smaller companies without the resources to fight the DSP war will be forced to license technology from the bigger companies effectively becoming brand name subsidiaries.Looking even further ahead, eventually OEMs will make DSP clones that undercut the prices of the big players and then it'll just be a race to bottom like the rest of the consumer electronics industry. Products will becomes disposable within 18 months of release.

author: b_force
author_rank: Super Contributor
timestamp: April 21, 2017, 12:04:53 pm
content: That's exactly what I said a few posts back.It's like digging your own grave.And ones again, that isn't new (and not only for the guitar market).I think your conclusion isn't that far off.I have seen that test with the Kemper.Their conclusions and results are scientifically a bit debatable.But it's about the principle, that there is virtually now difference, they are obviously just guessing and sometimes they guess it right.Bear in mind that Kemper isn't that much different than Line 6 from the inside.But because of the price they can get away with it.(If you just look at the BOM, and research, a Kemper is HEAVILY overpriced)I have seen similar tests with woods used in electric guitars.Also blind tests between a plywood one and some fancy expensive hardwood.As soon as people don't know/see what they are hearing/playing, not one single human is able to tell the differencesIt is ironic how strong placebo is.I play guitar myself (mostly acoustic, but every know and than electric).I know in theory it shouldn't matter, I know from measurements that there isn't a difference AND I confirmed it even with blind listening tests.Still, it just doesn't feel right without some old fashioned tubes (and maybe even a certain vintage look)Well, placebo pills even help people with pretty strong medical issues.I guess that says enough.

author: coppice
author_rank: Super Contributor
timestamp: April 21, 2017, 01:41:13 pm
content: Quote from: b_force on April 21, 2017, 12:04:53 pmI think its mostly people failing to be honest with themselves about motivations. If you idolise, say, Jeff Beck in his youth, or Jimi Hendrix its natural to look to the tools they used in the 60s. I fully understand why people want an actual 60s amp or pedal, or an accurate copy of it. A really cheap solid body electric guitar may not sound great, but it doesn't cost much to make one that sounds very similar to the most expensive. It takes somewhat more to make one that really feels good in your hands. Beyond that its about being pretty, or harping back to the good old days.Wanting that exquisite rare piece of maple for your guitar top, or wanting vintage equipment is fine, as long as you are honest about your motivations. It just gets kind of annoying when people claim magical acoustic properties.

author: b_force
author_rank: Super Contributor
timestamp: April 21, 2017, 02:43:11 pm
content: Quote from: coppice on April 21, 2017, 01:41:13 pmAmen!EXACTLY my thoughts!

author: james_s
author_rank: Super Contributor
timestamp: April 21, 2017, 07:09:45 pm
content: The placebo effect is a real, scientifically proven thing. If you believe there is something special about a particular instrument, it will sound better to you, even if nobody else can tell the difference. I just don't really have a problem with this.I recall a study somewhere that compared a genuine Stradivarius violin with a good quality modern instrument orders of magnitude less valuable. As I recall, the result was that the instrument itself made little difference, although musicians playing what was, or what they were told was a Stradivarius produced nicer sounding music. The effect was psychological, but what was surprising was that people who thought they were playing a Stradivarius actually played better, even if it the instrument was not what they thought it was.Engineering is driven by logic, reason and evidence. Art is driven by feeling and emotion. It's possible to create a copy of the Mona Lisa or other priceless painting that is so good that it takes close inspection by an expert to determine that it is not the real deal, to the engineer it is just as good, but it will never have anywhere close to the value of the original because it's not the original.

author: Zero999
author_rank: Super Contributor
timestamp: April 21, 2017, 07:55:07 pm
content: Quote from: BradC on April 21, 2017, 05:10:51 amSorry, none of that proves anything, due to the placebo effect which no one is immune to. It's quite possible that digital modelling can already replicate the valve sound (I don't see why not, taking it to the extreme imagine a SPICE simulation running in real time with transparent amplifies at either side) but whether it's scientifically proven or not is another thing. The modelling amplifier would need to be subject to a double blind test with a large enough sample size to prove one way or the other.Since, to my knowledge, no modelling amplifier has undergone rigorous double blind testing, strongly believing it's better, worse, or the same as a valve amp, is no different to believing in one religion, over another or none.

author: b_force
author_rank: Super Contributor
timestamp: April 21, 2017, 11:58:03 pm
content: It doesn't matter if it is proven or not.There are billion of examples, even very serious one (vaccination, anyone) and people WILL STILL believe in weird voodoo stories.Like you said, it's like believing in some sort of religion.Even if science is pretty clear and has pretty rock solid data.The person with the biggest mouth simply wins.Going back to my first post in this topic, I have been long (and skeptic) enough in the audio field that this is a very clear fact to me.A lot of people take what every you tell them, a big other percentage just almost like to believe and the marketing department is VERY willing to go with these stories.One a good story has settled in, it's like a parasite that is extremely difficult to remove.Btw, I people would like know a little more from a technical point of view.Go read 'Sound Reproduction' from Floyd Toole (he also has a seminar somewhere on youtube) and 'Loudspeaker Handbook' from John Eargle in combination with 'Loudspeaker and Headphone Handbook' from John Borwick.Together with some basic books about (general) acoustics and psycho acoustics and it's not difficult to understand that 80% from what you can buy on the market is just.......

author: bibz
author_rank: Contributor
timestamp: April 22, 2017, 04:15:43 pm
content: Yeah thats all fine but don't lump musicians with experience in with these audiofools. Just because theres 'amps' with 'tubes' doesn't mean its the same means to an end. We play our amps, literally. They are doing completely different things, and we expect completely different things out of them. And the simple fact is you CAN 'replicate' certain aspects of the supposed 'old' technology. But it will never be the same. MP3's cannot sound like vinyl either. Nor has an mp3 ever had a kickass gatefold.Theres no SPICE stuff I know of that can compute complex systems in real time, at atleast an audio rate of 44khz. And even then it'd sound crappy unless oversampled. Digital is great at getting near the ballpark, but if you want to step up to the plate the data and calculation needed speeds way past anything we could power. Even in F1 spending billions on aero and CFD they have correlation issues. The real world can only be approximated to a certain extent, and its no different for electrons. Kempers get close, but for any high gain sound it will stand out quite a bit. I've done blind tests, and I don't even have that good an ear, and I could pick out the real amp quite easily atleast half the time. That means it's close enough for most situations. It's also way more expensive then 90% of the amps you play in it. In music its not just the result either, but when you play different gear, you play differently. It's about the performance, its about the 'mojo' you guys keep mentioning. When I teach kids guitar I always recommend their first guitar be the one they like the most. I don't care how much it cost, how its made (I can get it to play fine), but if the kid likes it, they'll play it. Amp's are no different. If you only want to play SMT stuff with multilayer PCB's, then absolutely go for it!And Kemper is the same as Line 6? I suggest you go look up each product because they're literally worlds apart. One is a modeller. The other is a complex profiling system. The Axe-FX is somewhere in between. Also look up Nebula software. Theres a big world of digital approximation that have put serious time and effort into these things, and they still cannot replace actual hardware. Near enough isn't in pro environments.

author: Zero999
author_rank: Super Contributor
timestamp: April 22, 2017, 05:42:29 pm
content: Quote from: bibz on April 22, 2017, 04:15:43 pmThey do, if you create the MP3 from a track recorded to hissy, distorted vinyl. Of course the bitrate needs to be high enough to make the MP3 audibly transparent (i.e. the level of noise and distortion are inaudible) but that isn't difficult and if you want perfect, go lossless and use FLAC.QuoteThat just proves you can't tell the difference. Picking the real amp half of the time, proves the modelling amp is the same as the real amp. It's chance, the toss of a coin. If you could pick out the real amp more than half the time, i.e. with significantly better than 50% accuracy, then yes that would prove the modelling amp is different but only getting it right half the time suggests it's the same.As far as your other points you've made regarding aesthetics, records having nice artwork, the feel, ergonomics, cost, brand etc. and the influence it may have on your playing style, they're all perfectly valid but believing it actually sounds different, when can't prove it really does sound different, is fooling yourself.

author: David Chamberlain
author_rank: Frequent Contributor
timestamp: April 22, 2017, 08:28:32 pm
content: Being both a musician and engineer I can perhaps help to normalize this discussion that is fast becoming polarized. The differences here are between an engineering mindset and that of an artist.There is no doubt that modern DSP and other digital domain techniques are able to perfectly reproduce and modify signals well beyond the fidelity of human perception. I trust that is not a controversial statement. Why bring shortcomings of MP3 in to the mix when the OP was asking about guitar amps?From a performance perspective the artist embraces the fact that equipment is not able to reproduce the input signal correctly. The entire basis of a guitar effect is to "distortion" the input signal in one way or another. It is in the signal errors that something unique is found. The performance of a Supro Thunderbolt, that Jimmy Page used in 1969, will be completely different now and due to variability in manufacturing process and component tolerances at the time,the musical performance recorded on to what ever tape, under what ever temperature, humility, atmospheric pressure and so on can never be replicated. The performance is unique to that time / place / location.The fact that the variables cannot be controlled is the exact thing that give some musical sounds their uniqueness.That last point though underlines my main assertion that Audiofools are well... fools.The purpose of a guitar amp is to create a particular sound at the recording stage, while audiofools are OCD about reproduction of the original recording... and that is where it all falls apart. How can you reproduce something you did not hear (20-100 years ago)At least musicians and engineers alike can agree on that I hope.

author: Buriedcode
author_rank: Super Contributor
timestamp: April 22, 2017, 08:32:46 pm
content: So this thread went from... cheap paper PCB's in guitar amps (which do the job no better or worse than FR4 with SMT) to... whether or not 'real valve' amps can be recreated in digital modelling amps?[off-topic]As few people have both to compare, and of those, even fewer have the time to properly mic up cabinets and do a 'double blind A/B' test, often with these things - we just have to take the marketing with a pinch of salt and try them out for ourselves. There are so many components to 'guitar tone' (including the guitar, player, size/shape of room, I really could go on) that the more advanced amp modellers, whilst versatile, are time sinks just to get a half decent tone. And whilst you're tweaking, worrying about what sounds best - you're not playing guitar.I never bought the idea that some vintage amps with certain valves have 'amazing tone' properties. That bubble was burst in my teens when I tried out a bunch of expensive amps in a guitar shop - all too loud to hear much of a difference. Maybe tube preamp distortion has a certain tone, whilst saturation power amp distortion has another.. but what about the cabinets? Some gear sounds nice, some gear sounds crap, the only difficult part is finding a tone that means you just play more.We should be grateful we are spoiled for choice, and that even reasonable small, cheap amp modellers do an outstanding job and means we dont' need a full stack, with its cost, weight, size, room requirements, warmup times, reliability issues just to get a nice crunch. People often by gear so they can say they own that gear, not because they really do need a JCM900 with magic russian tubes. If they like that, good for them. If they want to worry about PCB vs point-to-point, good for them. If you don't like the sound of that amp? good for you.[/off-topic]As for the original topic. I have seen plenty of amp schems (done a few repairs too!) and generally the 'technology' hasn't changed much in 20 years. It doesn't need to. Using surface mount parts doesn't make much sense if half the design is power amp, and the preamp has BAGS of room in the amp head. Also, as far as I'm aware, large guitar amps are not 'mass produced' in the same way pedals are. And even 'hand wiring' can be good for marketing, so TH tech does the job. Sure you could probably make the preamp into a 2x2" PCB using SMT. But why? You still have to wire the pots to it, and you have so much room in the head that it brings no benefits.Sure there are certain upgrades for more modern amps, PhotoFET switching instead of relays or JFET's, MIDI channel selection (to be fair, even modern amps tend to use early 90's 8051-based micros). But it all depends on what you mean by modern?As the course of this thread has shown... anything 'more' you want a guitar amp to do, can either be done externally - using guitar effects, or becomes far cheaper to do digitally (as in, amp modelling). That latter of which *is* popular, Line6, Blackstar, Roland Cube, these are essentially just standard power amps with built-in digital modelling. This isn't quite the same as running a POD or Axe FX2 into a marshall stack, as they clearly tweak the EQ and amp models to work with the built-in speaker. That actual 'amp' part hasn't been updated much because there is no need. I don't see any reason why a guitar amp would use a class D amplifier, because a) they aren't batter powered, so efficiency is a moot point, b) Guitar amps are not 'HIFI' amps. They are designed to have a lot of distortion (even the cleanest clean) and do not cover the entire audio band. A HIFI amp makes a terrible guitar amp, and a guitar amp makes a terrible hifi amp.

author: ebclr
author_rank: Super Contributor
timestamp: April 23, 2017, 05:05:20 am
content: This isn't available in the 80S

author: SL4P
author_rank: Super Contributor
timestamp: April 23, 2017, 01:04:31 pm
content: In all the written comments, there was some brief reference to 'damping factor', but virtually no discussion of distortion, clipping or inter-modulation.And keep the power supplies in mind too!

author: bibz
author_rank: Contributor
timestamp: April 23, 2017, 01:15:37 pm
content: Quote from: Hero999 on April 22, 2017, 05:42:29 pmExcept I can hear it, and know its the real amp because of the high frequency content and depth. Its part of the tone. I can hear the deficiency. This was a blind test A/B'ing the miced up amp and cab, and the profile made of the exact same setup. Some of the played parts (using the same direct signal reamped) showed it off more then others. Its not A vs B, theres sooo much going on at any given time, hence the inability of total accuracy.I'm just arguing that you simply cannot 'perfectly' replicate a guitar rig. Yet. And even when you do, they'll still have their place. Experiencing this stuff live will hopefully never go out of fashion, and its much more impressive listening to a blaring marshall rig then a kemper over pa speakers. It's also much less impressive having to carry that rig vs a modeller.Just wanted to put some real experience in here as I know it backwards, love music technology and its progress, and love discussing it and hearing others perspectives on it. But saying Line 6 is perfectly representative is a decades old sticking point!

author: langwadt
author_rank: Super Contributor
timestamp: April 23, 2017, 07:06:54 pm
content: Quote from: bibz on April 23, 2017, 01:15:37 pmyou don't need total accuracy, but a coin toss will be right half the time, so to prove anything you have to be substantially better than getting it right than half the time

author: james_s
author_rank: Super Contributor
timestamp: April 23, 2017, 08:22:45 pm
content: Reminds me a little of the people who tell me I'm just imagining it and that it's not possible for a human to perceive the 200-400Hz flicker of PWM modulated LED backlights on some LCD monitors. Gives me a splitting headache and terrible eye strain, I can absolutely see the flicker, I wish I couldn't but I can, and some still smugly insist it's not possible.

author: julian1
author_rank: Frequent Contributor
timestamp: April 23, 2017, 11:30:12 pm
content: Can a DSP make a Strat sound like a Les Paul? The point of a Guitar tube amp is the sound it produces when over-driven and when the signal is not being faithfully reproduced. If a DSP can reproduce this, then how do you parametize the white noise generation? The signal FFT or spectral decomposition is just the starting point. You effectively need to model the output function for all possible chords, for all chordal transitions over time, for all the higher-harmonic frequencies, and for all the beat frequencies - and with all the different levels of sustain/attenuation over time.This is a completely different proposition, than an audiophile amplifier where the only thing is reproduction of the incoming signal - only at a higher dB output - all of which is easily measurable.

author: james_s
author_rank: Super Contributor
timestamp: April 24, 2017, 02:01:31 am
content: A lot of them can, at least in theory. I'm not a DSP expert but they can perform some impressive feats. Whether it sounds the same or not I can't say.

author: BradC
author_rank: Super Contributor
timestamp: April 24, 2017, 02:19:59 am
content: Quote from: james_s on April 24, 2017, 02:01:31 amI'm routinely floored at the transformation DSPs can do, and some of the V-Guitar stuff has been truely cool, but it's still different. If you want that Gibson SG plugged into a Marshall turned up to 11 sound, you really still need a Gibson SG and Marshall (preferrably with Angus Young in the middle). DSP can do a pretto good approximation, but they're still not all the way (yet). It'll come I'm sure.You'll never get a DSP that can make a Strat sound like a Les Paul though. It might do it for a fraction of a note, but you can _never_ reproduce the differing string decay characteristics of the wood and structure. So that's a non-starter. You could do it from scratch with a synth input (ie, note on, hold, vibrato... off), but using an analogue representation of the string vibration as an input won't work. The Strat note will have decayed away to nothing while the Les Paul will still be ringing at the gnab gib.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: April 24, 2017, 06:12:03 am
content: On the topic of "valves" vs "DSP": Musician myself here. I am confident that a DSP like the Kemper can get me any amplifier, and I won't be able to tell the difference in a practical scenario (and I'm quite sure I wouldn't be able to pull it off in a ideal situation either).I would like to point out that this is a bit more complicated of a story than the Tube VS Solid State debate in HiFi. In HiFi, we desire good linearity and low distortion - THD, IMD, etc. Butin guitar amplifiers, distortion is not only tolerable, but desired. This goes for both "soft distortion", due to nonlinear elements, but also "hard distortion" or clipping. On top of that, from what I understand, when dealing with tubes, these curves are alotmore complex in tube amplifiers because tubes tend to go into saturation more gently. This is the reason why modeling a tube amplifier's behavior in either a transistor-based circuit, or a DSP emulated version, was (is) so challenging. You are simulating systems that are supposed to be highly non-linear with wacky distortion behavior. It's also what gives certain tube amplifiers their "sound" - the way they filter and behave when distorting. In fact, to illustrate just how "complex" this behavior is, one of the big names in recent times in high-distortion amplifiers (guitar folk like to call them high-gain amplifiers since they usually put so much gain in the first few preamplifier stages that you can't help but clip your last few stages like mad) has multiple dials to "shape" the way the clipping behaves so people can fine tune their sound. However, modern DSPs are getting powerfull enough to simulate these complicated systems and they are starting to be a real contender.But there is one problem: The amount of knobs. The thing about those DSP "amplifiers" is that if I start from scratch, Icannotget them to sound any good. This is not because of the fact that it is a DSP, but because it gives me too much control. A tube amp has a certain flavor of sound. It has it's signature sound. And I find it a lot easier to get something I like out of them with a tube amplifier, because I can't mess it up. And that is, for studio and rehearsal work, the appeal of a tube amplifier. If you give me more knobs, I have to try and turn them, and before I know it I'll have something that sounds like turd, and I don't know how to undo it, or which knob did it.And, the thingglows. The fact that your cable goes into this box that has big, red hot metal things glowing away in them just makes you think you sound better

author: b_force
author_rank: Super Contributor
timestamp: April 24, 2017, 12:44:45 pm
content: Quote from: BradC on April 24, 2017, 02:19:59 amI think we have to go back to our course Control Theory again.YES you can, by definition. Unless it has a non-linear (phase) behavior.But all these type of things have linear-phase behavior. Some goes for distortion and all the other types.The difficult part is that a tube has a certain type (read: flavor) of behavior.That means that you have to mimic this or we simply have to get used to a different (new) flavor.But the discussion between guitar types is rather pointless IMO.We are talking about the amp and the effects, not about an amp and a different guitar.That's a whole different subject.For the same reason some conclusions are totally BS that people can sense (hear, see) certain things.Human senses also work on a certain way, have a certain bandwidth and a certain resolution etcIf you go far beyond these limits, it's by definition impossible to detect it.This also goes against one of the fundamental rules in science, making the wrong conclusions on the wrong assumptions.For example, if you DO see a flicker, instead the question should be WHY that is possible, because it is fundamentally impossible.A lot of times there is slight residual frequency (beat frequency) or other factors. Even the placebo effect get ruin your day here.(just the fact you know it's a switching light gives you the idea it IS flickering).Nowadays DSP's are more than sufficient enough to completely (99.8%) copy the behavior of tubes.In fact, this type of (audio) processing is rather easy to do.What makes me sad is that this discussion is going the wrong way for me personally (no offense)Almost like another pointing fingers, subjective, based on poor evidence type of discussion.(also many gossip stories about audio and what should be important)One again, the questions should be WHY.

author: Rerouter
author_rank: Super Contributor
timestamp: April 24, 2017, 01:15:34 pm
content: Well i found the derailing point on the second page,so to bring things back to the op's question, what defines the 1980 amplifier look?I personally am imaging, primarily through hole, semi or fully symmetrical layout per module, 1-3 large heatsinks covered in TO220 packages, likely made from black anodized aluminium, and curved trace corners, heavy use of Electrolytic capacitors, and no silkscreen.Funnily enough this pretty accuratly shares similar opinions to welder controller boards, the repairers all hated it when smd and microprocessing came along, even going so far as remaking the boards in analog to swap out, as they didn't like / trust the digital magic.

author: CJay
author_rank: Super Contributor
timestamp: April 24, 2017, 05:36:03 pm
content: Quote from: Rerouter on April 24, 2017, 01:15:34 pmWell, for me, these modules defined the 80's amplifiers (still available and looking very similar to the ones I used), I built a good number of them into amps for DJs, keyboards players and vocalists.http://www.bkelec.com/Modules/Amplifiers.htmGuitar amps, transistorised ones were mostly 2N3055/MJ2955 complimentary pairs or some other TO-3 package on anodised black heatsinks, hand laid out PCBs done with tape or just drawn, rotten biasing and drift, usually enough hum to make you wonder who didn't know the words but solid enough to survive the back of the obligatory knackered Transit/Bedford van.Valve amps, if they had a PCB (many were chassis built with tagboard and valve sockets) were similar, hand drawn layouts, perhaps done with tape on transparency, large glass enamelled wirewound resistors if you were lucky and overheated boards because the power components weren't fitted properly, ventilation on both valve and transistor types was often woefully poor or easy to obstruct and if it was good then it was prone to having a distinct smell of beer.Happy days.

author: james_s
author_rank: Super Contributor
timestamp: April 25, 2017, 06:27:03 am
content: Why is it fundamentally impossible to see high frequency flicker? If I strobe an LED at a few hundred Hz, look to one side of it the look to the other side of it, I see a string of dots as my eyes scan past the rapidly flashing LED. When I look at a monitor my eyes are not glued to a single spot, they are following the text I'm typing, the mouse pointer, the page I'm reading, etc. I can tell at a glance if a monitor has PWM LED backlight dimming, at least at the frequencies that cause me trouble.Clearly not everyone's eyes and brain have identical characteristics. I remember people who would run 60Hz refresh on a large CRT and say they couldn't see the flicker but most people can see that.

author: Siwastaja
author_rank: Super Contributor
timestamp: April 25, 2017, 06:43:57 am
content: Quote from: james_s on April 25, 2017, 06:27:03 amLike some people have stronger sense of smell, or better eyesight, the persistence of vision is personal, too. I bet no one questions theconceptof flickering, and everyone would notice 50Hz LED backlight PWM, but not everyone sees 400Hz. (Important factor here is that, especially at low duty cycles, the spikes are very energetic and sharp, so these rates do not correspond directly to the CRT scan rates, where the phosphor persistence is a smoothing factor.)

author: Zero999
author_rank: Super Contributor
timestamp: April 25, 2017, 07:46:34 am
content: Quote from: Siwastaja on April 25, 2017, 06:43:57 amYes that's true, some people are able to hear higher frequencies too, possible over 20kHz, in some children but not dramatically higher.As far as persistence of vision is concerned and flicker. It depends on the duty cycle, intensity and the point in the observer's visual field.I didn't know LCD screen back lights were driven with PWM. The older CCFL types are certainly driven with a constant AC current above 20kHz and I'm pretty certain no one will be able to detect that. The newer LED back lights might be driven by PWM at lower brightness settings but 400Hz does sound like a low frequency for that. It's certainly plausible someone will be able to detect that, especially if it beats with 100 or 120Hz content in the ambient lighting.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 25, 2017, 08:32:15 am
content: Since we are already deep in off-topic territory

author: Cerebus
author_rank: Super Contributor
timestamp: April 25, 2017, 06:29:31 pm
content: Quote from: Hero999 on April 25, 2017, 07:46:34 amThe record is something like 26-27 kHz insomeasthmaticchildren. Whyasthmaticchildren no one has been able to adequately determine but some have been observed to have unusually high hearing limits.

author: james_s
author_rank: Super Contributor
timestamp: April 25, 2017, 07:27:33 pm
content: Not all LCD monitors use PWM dimming, even the LED backlit ones. Some of them use higher frequencies or otherwise do not bother me. The LED backlit screens on my laptop and desktops at home are fine, we have some Lenovo desktop monitors at work though that are horrid, I had to swap mine out for some older CCFL backlit monitors, headaches went away. With those it wasn't so much that I could see the flicker, it just felt awful to stare at them and then I noticed if I looked to one side then rapidly scanned my eyes over to the other side or waved my fingers in front of the screen I could see the strobing.When I was younger I remember I could hear the 15kHz whistle from CRT video monitors very clearly, I remember walking into a classroom in highschool multiple times and mentioning to the teacher immediately that someone from the earlier video production class had left a monitor on and she was always amazed to find that there was in fact one left on with no signal to it. I had a CGA monitor on my 286 that made an awful whine, my dad couldn't hear it but it was absolutely piercing. Now that I'm older I can barely hear frequencies that high and it's actually a bit of a relief. My partner is a few years younger than me and she often complains about the noise when I'm working on an old CRT monitor or some switchmode regulators.

author: ErwinB
author_rank: Newbie
timestamp: May 03, 2017, 06:32:35 pm
content: Quote from: bibz on April 23, 2017, 01:15:37 pmJust like recording technology that went digital before it, modeling amps need to be very carefully set to avoid clipping in the digital sound path. Or you get aliasing which is not pretty. Using tape it was commong practice to saturate the tape a bit. The first digital recorders that came in the reach of amateur engingeers tended to sound very harsh. Part of it was the lacking technology of the period (second half of the 90's) part was that a lot of the engineers had not learned to work with it. This improved with the arrival of 24bit 88kHz or 192kHz recording that allowed for more dynamic range and allowed for more room to stay away from the 0db line.Someone made the point that modeling technology made for great live equipment. In my experience it is mostly used to record. While being flexible to switch between different models on the fly, there is sometimes a significant gap when the dsp's are hard at work. something you cannot have live. That is one of the main reasons that this technology is making serious inroads recently. The fact that SOC's have become so powerful that these can be used now with of the shelf software. What still is needed are good impulse recordings an making these and tweaking these recordings is very costly as you need the original equipment and engineers that have the knowledge to do so.

author: Cerebus
author_rank: Super Contributor
timestamp: May 03, 2017, 10:35:03 pm
content: Quote from: ErwinB on May 03, 2017, 06:32:35 pmUntil the mid 70s the standard method of aligning a tape machine was to set the gain for a +4dBm input signal to the point that caused 3% distortion on tape. Input levels during actual recording would be at around -10VU leaving only occasional peaks to experience that 3% distortion. The soft limiting caused by tape wasn't particularly objectionable, you needed good ears to detect it was happening. Some people did indeed deliberately use tape as level compression - if you want to know what that sounded like, listen to any Phil Spector 'wall of sound' recording.The line-up by distortion level was superseded by an absolute magnetization standard where +4dBm produced 200 nWb/m or 320 nWb/m depending on which standard (NAB or IEC) you were working to. The price of a 2" calibration tape was quite something to behold, as was the weeping of studio managers when they discovered how often those tapes needed replacing.

author: mfratus2001
author_rank: Contributor
timestamp: May 05, 2017, 10:16:38 pm
content: Well, I repair guitar and audiophile amps nearly every day.I've worked on literally thousands of amps of all sorts... here is my take.People like old tube amps because they sound good, and are very reliable. I routinely see 50 year old amps that just need a little TLC, like cleaning the controls and jacks. Even the original tubes are often still working fine.Tube amps have gone through the same development process as everything else. Point-to-point at first, then eyelet boards, then turret boards, then PCBs. Most companies that care about reliability don't mount their tube sockets on their PCBs. That would be dumb. Most often they are chassis-mounted with the circuit board close by.There is a mix of products today. "Hand-wired" is a good marketing buzzword, but it really does not mean anything. Everything is wired by hand. We don't have robots agile enough to do it.Some users are anti-PCB, and that is most often because the boards are laid out by people who have no idea how to properly isolate signals and avoid interaction. Often, it is the ground circuit that is the culprit. I have had to cut PCB traces and re-route grounds on production units just to cure noise and hum.Most of that is probably from the circuit design person being remote from the actual builder. Probably also the PCB layout person is also remote from both of those. You have to work as a team, and there has to be a closed-loop for performance and quality. The prototypes may sound fine, but production units are often troublesome.It is hard to integrate digital systems with audio systems. It is hard to integrate solid-state and vacuum tube electronics. But neither of these is impossible.You can replace tubes, but it is hard to replace transformers and the interactions between the tube or tubes, and the transformer. There are things going on like magnetic saturation and hysteresis that are just really hard to model.Some modeling amps sound pretty good, some pretty bad. The biggest problem is that they only capture performance at a certain setting of controls. They don't fully simulate the whole amp experience through all variables of input and control settings.So, PCBs are not the problem. Lack of proper engineering is a problem. Lack of attention in construction practices is a problem. Choices in these that are made just to have good marketing buzz-words is a problem.Early tube amps were relatively simple. Maybe it is that circuit simplicity that makes them sound so good.