Tubes (Valves) vs. MOSFETS in Audio Amps - A Definative Look?  - Page 1
Forum section: electronics / general

author: bullet308
author_rank: Frequent Contributor
timestamp: August 20, 2012, 04:52:51 pm
content: As somebody that has remained essentially agnostic in this multi-decade-long fight, I find this interesting...http://electronicdesign.com/article/analog-and-mixed-signal/-House-of-Fire-Firebottles-And-Groove-Tubes-Versus-Devices-That-Find-Their-Origins-in-Sand-Part-1-

author: djsb
author_rank: Super Contributor
timestamp: August 20, 2012, 06:44:10 pm
content: And part 2http://electronicdesign.com/article/analog-and-mixed-signal/Tubes-Versus-Solid-State-Audio-Amps-The-Last-Word-Or-House-Of-Fire-Part-2-I'll have to have a good read of this at the weekend. I'd love to experiment with valve/tube audio. Maybe when I retire.

author: poptones
author_rank: Frequent Contributor
timestamp: August 20, 2012, 11:53:16 pm
content: Yeah, a fun read but it really doesn't bring much new to the table. I've read articles like this in journals dating as far back as 1957, and the discussion still goes on. You've got people who refuse to believe we can hear ppm differnces in sound qualities, you've got people who insist measurements are the end of the discussion, and you've got people who insist measurements mean nothing. None of these people are wrong.To quote the Gizmo:"There is not only NO MUSIC OUT THERE, there is no Absolute Sound anywhere on this earth. There is no music IN Carnegie Hall, when the orchestra is playing its heart out. There is no music AT the Blue Note. There is no music emanating from our favorite speakers. Out there is only noise, which only becomes music, (which is an emotion just like, love, hate, courage, fear, courage, faith) when it enters our body, and is decoded."There are those for whom a car is a tool to get them from point A to B, and those for whom every minute behind the wheel is a new adventure in performance. There are those who want a noise to dull the silence, and there are those for whom every moment is a symphony of sound. None of these people are wrong, they are only different - and you'll not likely ever get the differing camps on the same page.A MOSFET amp will never equal a tube amp, no matter the sound quality. It's like watching fireworks on TV.

author: GK
author_rank: Super Contributor
timestamp: August 21, 2012, 12:36:08 am
content: That is a pathetic article. I particularly like this line:“We can also hear subtle differences in music passages that are 130 dB down from the highest signals”.With the (frequency dependent) threshold of hearing set at 0dB at 1-kHz, the established “threshold of pain” is actually at the 120dB level. This is an impressive dynamic range but it does not therefore follow, nor is it a demonstrated fact, that anyone can hear sounds at the 0dB level and sounds at the 120dB level simultaneously.

author: poptones
author_rank: Frequent Contributor
timestamp: August 21, 2012, 12:42:23 am
content: See? I told you.It hasn't been settled since 1957, and it never will.

author: GK
author_rank: Super Contributor
timestamp: August 21, 2012, 01:12:15 am
content: YAWN!Anyone who insists that they can hear ppm differences in amplifier distortion is, for all sakes and purposes, as deluded as anyone who insists that they can read a seeing eye chart unaided from 500 meters.

author: T4P
author_rank: Super Contributor
timestamp: August 21, 2012, 02:36:23 am
content: One thing's for sure : Tubes can never Mosfets in terms of performanceIt's always overdamping that makes mosfet amps sound not that good

author: Zero999
author_rank: Super Contributor
timestamp: August 21, 2012, 01:34:32 pm
content: It's all total nonsense. Providing the amplifier is any good, the only audible distortion should be in the speakers and room acoustics.

author: SeanB
author_rank: Super Contributor
timestamp: August 21, 2012, 01:58:52 pm
content: I used valve amplifiers for audio, as they were there and worked. When I upgraded ( replace all with another improved lot) I still used them, as they only had to deliver low fidelity audio, and at least were transformer coupled so one less source of ground loops. Made by Siemens for some telco or instrumentation use in the 60's and still working, though the use I had for them was eclipsed by technology changing.

author: Skibane
author_rank: Contributor
timestamp: August 23, 2012, 05:37:15 am
content: Quote from: GK on August 21, 2012, 01:12:15 amMeanwhile, the speakers they're using to "audition" the amplifier are doing damned good to keep distortion down in the parts-per-hundred range...

author: RCMR
author_rank: Frequent Contributor
timestamp: August 23, 2012, 07:43:21 am
content: One of the advantages of getting old:My 1960's music still sounds as good as it ever did -- even when I'm listening to a 128kbps MP3 file on a $10 Chinese media-player.Long live age-affected hearing!

author: MetraCollector
author_rank: Regular Contributor
timestamp: August 23, 2012, 08:22:51 am
content: Ultra hifi people are funny to read, aren't they ?I know few who would swear to god that red WIMA capacitors have better tgD than grey Arcotronics on the 10th after decimal point and THIS would rapidly improve soundMore golden PCBs you have, more treble tones you getIf you have repro-cables with silver fibers made by african silver-melters, you have rapidly better bass tones !

author: merlinb
author_rank: Contributor
timestamp: August 23, 2012, 12:16:17 pm
content: Transistor amplifiers clearly outperform valve amps in every possible way, expect possibly aesthetic appearance. And yet people LOVE valve amps. Clearly "fidelity", in the truest sense, has little to do with actual enjoyment of reproduced music.I think the subjectivists would garner a lot more respect if they played the pscho-acoustic-emotional card more, and stopped trying (and failing) to explain their theories about directional cables and magic capacitors using psuedo-engineering.Any real engineer can show that a £20k is no better than a $100 cable, and therefore that they cannot possibly sound different, or that the valve amp is woefully deficient in technical terms, compared with the valve amp. But our silly human brains ensure that we willenjoythe music more if we have forked out $20k for that damn cable, or lovingly constructed our crappy valve amp by hand, and therefore those products are still justified.So the subjectivists don't need to invent silly theories about streamlined electrons and ley lines, they can simply argue from the perfectly true and scientificpsychologicalperspective, that valves, silver wire and expensive capacitors are worth using because ourperceptionof their quality and 'niceness' is all that is required to make the music sound better in your own head!

author: poptones
author_rank: Frequent Contributor
timestamp: August 23, 2012, 10:03:42 pm
content: Transistor amplifiers clearly outperform valve amps in every possible way, expect possibly aesthetic appearance.Wow. So an LM386 amplifier is clearly superior to a 6L6 JoLida?ROTFL. What sort of objectivity is this?

author: GK
author_rank: Super Contributor
timestamp: August 23, 2012, 11:50:32 pm
content: Was that supposed to be an intelligent contribution? There isn’t a measurable parameter for any tube audio power amplifier that cannot be easily bettered by an order of magnitude or more in a solid state design. What does an LM386 have to do with anything?

author: poptones
author_rank: Frequent Contributor
timestamp: August 23, 2012, 11:54:50 pm
content: Was THAT supposed to be an intelligent contribution?So... an LM386 has tens of percent distortion at a fraction of a watt. It has high output impedance. It has high IMD even at low power levels...The only meaningful parameter is how it sounds to the listener.

author: GK
author_rank: Super Contributor
timestamp: August 24, 2012, 12:31:23 am
content: Quote from: poptones on August 23, 2012, 11:54:50 pmYes it was, but I appreciate that the content may be beyond your capacity to comprehend.If the “only meaningful parameter is how it sounds to the listener”, then why are you basing your derision of the LM386 on its measured specs?I take it I’m either feeding a troll here or someone <15 years old.

author: AntiProtonBoy
author_rank: Frequent Contributor
timestamp: August 24, 2012, 12:37:59 am
content: Someone should just integrate a fleshlight into an audiophile amp, and be done with it.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 24, 2012, 01:41:34 am
content: Isn't the main reason why some think tubes are better than transistors is because they aren't? Or more precisely, they're imperfect in just the right way to make cool effects.I read that they now figured out how to make microscopic vacuum tubes on a chip, so those tubes could well make a comeback!

author: GK
author_rank: Super Contributor
timestamp: August 24, 2012, 02:05:23 am
content: Quote from: NiHaoMike on August 24, 2012, 01:41:34 amYes it is, and especially so if the designer of a tube amplifier had eschewed global negative feedback in his design. Open loop, single ended triode amplifiers with awfully microphonic directly heated tubes have somewhat of a cult following.The problem is the pretentions of a typical audiophile won’t permit him to admit to the fact that this is, for the most part, an aberration from “high fidelity” and the “accuracy of reproduction”, nor to the fact that the nature of the coloration he hears is due to parameters of the amplifier that are in fact quantifiable and measurable. It's always something supposedly more lofty, mysterious or spiritual and ignorance is bliss.I write this as someone who does 90% of his listening through a number of tube amplifers, which includes an open loop (2A3) S.E.T. amplifier.

author: Rufus
author_rank: Super Contributor
timestamp: August 24, 2012, 02:08:31 am
content: Most of this crap could be sorted out by ABX testing. I searched around thinking I would find more results not having looked for ages but didn't.I did find some remarkably bizarre arguments against ABX testing. It seems no one with an interest in 'high end' audio or in possession of golden ears wants any objective testing.

author: poptones
author_rank: Frequent Contributor
timestamp: August 24, 2012, 04:44:04 am
content: A lot of what many (maybe most) of you are basing your strawman on is the notion of SET amps and the boutique culture that surrounds them. If you believe that nothing matters but ABX double blind, or even measured specs, then any competent engineer should immediately realize the jist of the argument here comes down to topology - so most of the comparisons here are being made apples to oranges. A Single Ended Triode amp is, by its design, intended to imbue its own sound onto the music. If this offends you, well no one is making you buy one. But you cannot lump the likes of a Cardinal amplifier into the same basket as, say, an Audio Research Reference 750 which would put most solid state amps to shame in a bench session.Design an amp with, say, 80db of open loop gain. Stabilize it with 60db of negative feedback. You really think the difference between tubes and transistors amounts to more than preference?

author: GK
author_rank: Super Contributor
timestamp: August 24, 2012, 05:40:45 am
content: For someone constantly complaining about strawmen, you sure do a good job of erecting your own.

author: T4P
author_rank: Super Contributor
timestamp: August 24, 2012, 01:32:41 pm
content: Quote from: poptones on August 23, 2012, 11:54:50 pmWoah you are widly misquoting things here1) LM386 is not designed to be a WOW HIGH POWER MONSTER2) LM386's main application is not even a headphone amp3) Do you find LM386 in equipment? Nope only cheapies4) How many volts do your poor tubes need? Sorry we only need 12V5) tens of percent? I think you mean 1% @ 12v @ 0.25WYour way of comparing amplifiers make tubes look magnificent but you need to look at the contrary6) It's very cheapHow about you compare your 50W 6L6GC's to a LM3886?Hilarious ... plain hilarious comparing a IC to a tube that needs so many support componentsHow about comparing the LM386 to a submini tube?

author: poptones
author_rank: Frequent Contributor
timestamp: August 24, 2012, 01:51:26 pm
content: Again , I can't tell if you're kidding or not.An LM3886 needs a power supply and a handful of capacitors. A tube amp needs... a power supply, an output transformer, and two resistors. Design the power supply correctly and it needs one resistor.Transistor amplifiers clearly outperform valve amps in every possible wayThis is idiocy. The assertion was that any transistor amp easily exceeds the specs of any tube amp. That's as ludicrous as saying motorcycles are faster than cars.

author: madires
author_rank: Super Contributor
timestamp: August 24, 2012, 02:03:54 pm
content: Quote from: NiHaoMike on August 24, 2012, 01:41:34 amYep! Audio driven by a MOSFET amp is considered "cold" or "plain". If you look at the specs you got a nearly linear amplification between a few Hz and 100kHz or even more, low distortion and what have you. The tube amp has a "warm" sound. And if you look at its specs you wonder how someone could prefer a tube amp. The distortions created by tubes are ideal for the human ear & brain. Most guitarists prefer tube amps for that reason.For people who like to take the best of tubes and MOSFETs there's the solution to add a pair of tubes in one of the pre-stages to gain that warm sound and the MOSFETs will amplify those nice distortions. If you add a bypass-switch you can even choose between warm and cold sound based on the music you listen to.

author: merlinb
author_rank: Contributor
timestamp: August 24, 2012, 02:49:07 pm
content: Quote from: poptones on August 24, 2012, 01:51:26 pmI think it's pretty obvious from the thread and context that we're talking about comparinghifiamps, not run-of-the-mill chip amps and other toy devices. Even a relatively basic tranny amp can outperform the 'best' valve amp in everytechnicaldetail. But not in user acceptance!

author: T4P
author_rank: Super Contributor
timestamp: August 24, 2012, 03:22:32 pm
content: Quote from: poptones on August 24, 2012, 01:51:26 pmYour idiocy ends here.Of course you wouldn't need caps for a tubeTHERE'S THE VERY EXPENSIVE OPT TRANSFORMER!And can you please explain why any 50W Class AB operation tubes are so GOOD at being a room warmer?And that tubes take up so much more space for just 50W?

author: poptones
author_rank: Frequent Contributor
timestamp: August 24, 2012, 03:25:56 pm
content: Even a relatively basic tranny amp...Are you sure it's not really a girl?can outperform the 'best' valve amp in every technical detailYou would call a 750W amplifier "relatively basic?" But what if it really was a tranny? Wouldn't that make itfabulous?

author: merlinb
author_rank: Contributor
timestamp: August 24, 2012, 03:31:55 pm
content: Quote from: poptones on August 24, 2012, 03:25:56 pmHuh? What's 750W got to do with anything?

author: T4P
author_rank: Super Contributor
timestamp: August 24, 2012, 03:32:37 pm
content: In terms of distortion and simply everythingYour dear 750W tube amplifier requires 3 phase power and massive transformers and lots of circuitry as well highly rated resistorsThe last time i checked a not so efficient 750W mosfet class D amplifier does not use more than 900W!

author: poptones
author_rank: Frequent Contributor
timestamp: August 24, 2012, 03:33:59 pm
content: Seriously... you'retryingto troll now, right?

author: poptones
author_rank: Frequent Contributor
timestamp: August 24, 2012, 03:35:41 pm
content: Huh? What's 750W got to do with anything?About as much to do as trannies... but I'm not the one who broughttheminto the conversation!

author: free_electron
author_rank: Super Contributor
timestamp: August 25, 2012, 04:34:25 am
content: Anything inbetween the instrument and the ear adds distortion.The perfect amplifier would only change amplitude and not imtroduce distortion or bamdwidth limitation.The same goes for speakers or microphones.The same goes for recording mediums.So, here's to all the audiofreaks out there : give it up. Throw away all your equipment as it is useless. You will never even come close to actually putting yourself in place of the microphone and listen when it was played in the first place. Any mechanical or electronical contraption is only intermediate and adds distortion. It is a lost battle. Your only hope to reach perfection is to actually sit in on the actual performance. Knowing that you will never hear it again as you hear it now

author: bullet308
author_rank: Frequent Contributor
timestamp: August 25, 2012, 04:43:23 am
content: I see that my link has failed to resolve the issue. I am shocked beyond words...It would seem that it mostly boils down to a matter of what kind of distortion you prefer.