Audiophoolery Episode Re-Visit - Page 1
Forum section: electronics / general

author: HexiBase
author_rank: Newbie
timestamp: July 26, 2010, 05:33:08 pm
content: I had already mentioned this on YouTube but then realized that it probably got lost in the mix... Anyway, valve amps: I know you're not a big fan of tubes, but do you think that there's any place for them in audio signal amplification?I consider myself to be an audiophile; I'm a very critical listener, I design and build my own speakers but, I've auditioned a few Decware amps, and, as much as I strain my ears, I simply can't hear this supposedly apparent advantage of tubes over well-engineered solid state circuitry. Yet there's an entire industry built around tubes; amplifiers that cost more than my car... Is there anything to it? At all? I know there's plenty negative that you can say about tubes, but what could possibly be said in their favor?

author: TheWelly888
author_rank: Frequent Contributor
timestamp: July 26, 2010, 05:54:36 pm
content: Tubes look a lot prettier than TO220 and TO3 cased transistors bolted to aluminium extrusions! That's about the only thing going for them in my opinion! I don't think it's worth one of our Dave's rants though...

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 26, 2010, 08:31:30 pm
content: Quote from: TheWelly888 on July 26, 2010, 05:54:36 pmTransistors are boring to look at since you can't see the inner workings. Well, except for those:http://techno-fandom.org/~hobbit/cars/ginv/i2compon.htmlIf I were to design an amplifier using those transistors, I would put them along with the other power electronics in the top, with the drivers and logic on a board next to it. The top cover would be made of glass or clear plastic to allow everything to be seen, and LED lighting designed such that the LEDs near the transistors are varied in brightness and color according to the average and peak currents of that transistor. And the defective transistors would be made into necklaces as they're just so beautiful and will match the amplifier nicely.

author: EEVblog
author_rank: Unknown
timestamp: July 26, 2010, 09:18:36 pm
content: Quote from: HexiBase on July 26, 2010, 05:33:08 pmNothing in terms of signal quality. Tubes are generally inferior performance and so usuallydistortthe sound giving supposed superior *insert wank word*.I believe there are some advantages in terms of high voltage/power performance but that's it.But basically it's a crock of shit.My analog mate Doug.F is a world class audio designer, and told me a story about how he designed a valve into a (very big name) commercial microphone preamp. Not because it sounded better but because it met some obscure design requirement at the time.Dave.

author: saturation
author_rank: Super Contributor
timestamp: July 26, 2010, 11:18:38 pm
content: Did he specify Richard Grey Audio "RGPC HighTensionWire" powe cables? They are only $450 for 1.5'http://www.big-georges.com/richardgrayspowercompany-hightensionwire.aspxI think if I put them on my PC I can get more bass out of my audio card!It costs as much as a Rigol 1052Ehttp://www.richardgrayspowercompany.com/products.aspx?type=accessoriesQuote from: EEVblog on July 26, 2010, 09:18:36 pm

author: EEVblog
author_rank: Unknown
timestamp: July 27, 2010, 02:48:27 am
content: Reply from Doug about the advantages of valves in commercial gear he's designed:QUOTE:Technical reasons be buggered!It was purely sales/marketing, to appeal to the wankers who think choobssound better than solid-state (which was once true of course, back inthe '70s).The Rode Classic-II uses a choob operating with about 20dB gain followedby (shock, horror!) a transistor emitter-follower hung off the anode.This gave a low-Z drive point for the high-pass filters and outputtransformer, and dramatically reduced THD.Circuit noise is defined by the choob's operating conditions; Thetrannie contributes bugger-all noise.The other one was the Rode NTK.I'm proud of this beastie; It has an absolutely awesome dynamic range of(from memory) more than 145dB.A microvolt or so of noise, but capable of 35V RMS output voltage.Self-noise equivalent to 12dB SPL, but can handle nearly 160dB SPLwithout clipping the electronics.I used the choob as the front-end of a closed-loop power amplifier (yes,more bipolars) with a 120V rail.The condenser mic capsule is directly coupled to the grid - i.e. noinput coupling caps.A few other circuit tricks gives it extremely good PSRR which, combinedwith a pretty clean PSU, means mains-frequency crap is way below thebroadband noise floor (unlike the noise spectra of most choob mics).This thing's a brute; I connected its output directly to a 32-ohmheadset, and it was LOUD.Mind you, it's still noisier than the NT1000 (JFET, <6dB SPL equivalentnoise).After I left, Rode shoehorned my NT1000 electronics into one of theirolder mics, which had a more sensitive capsule, and achieved 4dB SPLnoise.With these seriously low-noise condenser mics, on a clear night you canhear the curry percolating through the intestines of the family in thenext block./QUOTE

author: MightyTwin
author_rank: Contributor
timestamp: July 27, 2010, 03:02:12 am
content: Quote from: EEVblog on July 27, 2010, 02:48:27 amWow. Fascinating to read through!Doug, you need to get an account on this forum! I'd love to see you comment on audio related threads.-MightyTwin.

author: DJPhil
author_rank: Frequent Contributor
timestamp: July 27, 2010, 03:36:09 am
content: I agree so far with one minor qualification: Guitar amplifiers, or all instrument amplifiers where the amp is part of the instrument.The distortion rendered by valve amps can be very difficult or costly to replicate with solid state gear. There's nothing magical about valve amps, it's just that they distort in so many interdependent ways that it's a complex system to model. Those working on a hobby budget might choose to simply shell out for the parts for a valve amp to save money and time getting the tone their after, and I respect that. I myself prefer the much greater flexibility (and safety) of working with solid state, as you can get awfully close without dealing with the numerous drawbacks.Concerning all else, I'm with you guys. Valves really don't seem to be suited for much nowadays other than producing their characteristic distortion (maybe VTVMs?).I just wanted to throw this in because six months ago I was completely convinced that valve technology was obsolete in all respects. At least for this one thing, a rational and empirical case can be made for valve amplification.

author: EEVblog
author_rank: Unknown
timestamp: July 27, 2010, 03:44:17 am
content: Quote from: DJPhil on July 27, 2010, 03:36:09 amFraid not. VTVM's were replaced by FET VOM's in the 70's, which in turn were replaced by Digital meters in the 80's.Dave.

author: ThunderSqueak
author_rank: Unknown
timestamp: July 27, 2010, 07:25:12 am
content: Valve amps do make a difference in guitars! If I am playing my telecaster for another musician and tell them I am playing through a t00b amp my "tone" instantly gets a 110% better ratingA+++++++ Would buy from again!edit:My point to this post is a lot of people honestly cannot tell the difference between a tube amp and something like a line6 POD (solid state amp simulator). The reason is, most effects and other things people do to change their sound are solid state. If you look at a lot of guitar amps these days they have a tube in them, not because it really changes the sound, but because it is a marketing thing. The rest of the design on said amps is solid state. That being said, I still like my little tube amps... their is something to be said about a device that can light up the room, and heat your home in the dead of the Alaskan winter

author: HexiBase
author_rank: Newbie
timestamp: July 27, 2010, 09:14:55 pm
content: Excellent responses, everyone. In a way, I wasn't sure whether or not this thread would even get taken seriously. In reading what everyone had to say, I wager that the tube vs. solid state debate isn't quite as technical as it is psychological. Obviously we can't quantify the nostalgic "warm fuzzies" that some people get from the prospect of having a tube someplace in the amp / pre-amp stage. But we can't really quantify a subjective listening experience either. The empirical comparison ends at the speaker's terminals... Well, maybe 1m forward of the speaker, if we venture into the realm of acoustics. All things considered, this really seems to be a debate of signal vs. tone.

author: squeezee
author_rank: Contributor
timestamp: July 28, 2010, 12:52:23 am
content: Quote from: HexiBase on July 27, 2010, 09:14:55 pmThat's quite often what it comes down to. Also might want to take a look at thisvideo on youtube which says much the same.

author: Time
author_rank: Frequent Contributor
timestamp: July 28, 2010, 01:26:00 am
content: Quote from: squeezee on July 28, 2010, 12:52:23 amCool video