I am saying that if in fact, tubes marked 6L6 are manufactured to the same specification as the design, they will sound the same. I submit that sounding different is very subjective and is also because they are not really a 6L6. I do not believe in one tube sounding "fuller" or having "better highs" or "having more presence" or as they say, "The warm tube sound". If there is a difference, it is most likely what surrounds the tube. Of course, tubes that are manufactured incorrectly will "sound" different because they do not perform in a circuit that was designed for them. There is too much smoke and mirrors surround this subject.

azenithnut, where did you get the covers for the edcors?

Here is what I am referring to...

http://www.audiokarma.org/forums/showth ... p?t=415507

Those are cast aluminum relay covers I found at Mendelsons Electronic Surplus. I had to cut them down and paint them.
If I had gotten the newer GXPP style transformers, I would have left them uncovered. But mine are the older naked style without the nice blue covers.

-Steve

I really hear what you are saying but I am referring to simply tubes that meet design parameters. Yes, if some test differently, they may sound different. And I think the reason they "sound" different is because they are no performing as designed. Think about the fiasco of the 7591XYZ that was floated out there. Most likely a 6L6 that was re-based to capture some of the money available from guys like us looking for a 7591 for cheap. When you have to change resistors in the circuit (7591XYZ) that tells me that it is not a 7591.

Getting back to the original question, I seriously think that a tube that is what it is labeled will "sound" the same. If it does not, it is no longer what it is labeled.

As for TEK, they wanted the best that they could get. They were not talking audio. I am. And I am not talking about matching tubes, I am talking about "The black plate RCA sounds more rich, with warm mid-range than the GE gray plate which sounds...." That is what I am looking for...

The only issue I know about the color of the plate is a black plate can dissipate more heat therefore handle more power easier than a grey one could. Just the physical nature.

The black one should last longer under extreme operating conditions.

BTW, Tin omen, your amplifier looks very impressive! I don't know why it didn't show up on my screen earlier. I don't think I'm blocking Photobucket...

I like the meter and eye tube! I'm supposing you can switch the meter for different functions and the eye acts as a VU meter?
-Steve

The meter is a weston that I had to make a front for. It reads the current for eash tube (about 60ma) and B+ about 325.
The eye tube is a 6AF6, and a 6F8G runs it.

Here's the insides:

The tubes are 1625s, 6F8s, 6C8s, and 5V4s.

And my newest a GU-50:

With all Russian tubes. This one has Edcor's GXSE15-8-3.5K. And my handmade hard maple chassis.

My favorite 6L6...

Great thread on 6L6! Thanks.

Maybe this is comment borders on metaphysical senses, but when I see amplifiers built like those belonging to Steve and Tim shown here, my hearing perceives a much richer sound perhaps because I'm thinking of the intelligence and workmanship that created the fabulous man made devices. Well done!

Jack

I had a brand new quad of Electro-Harmonix EL 84's; when placed in the amp, it sounded like someone had turned the treble control down a full quarter turn; highs were muted to say the least. With a difference that large, even casual listeners would notice.

As for being happy with a particular 6L6, an amplifier with all-metal looks very good. As to glass,
the old 6L6-G. The big glass conveys the idea that this indeed will do the job.

Any 6L6's that are in my basement and still work....

Mike

Here's another I made with Russian 6P3S-Es, they are supposed to be 6L6GB or 5881s. The Russians also made the 6P3S, which are copies of the 6L6. They do look alot like a 6L6.

OK, "hear" we go again..
Tubes sound good (to many folks) because of the nature of the distortion and, yes, even microphonics that color the sound. Tek wanted linear, balanced signal processing that did NOT "color" the signal under test.
Sure, randomly-selected same-make and/or variants of a true 6L6 may sound different. Some have better vibration tolerance. Some have different bias needs or even slightly different slopes. A curve tracer will readily show that in a way that is understandable.
Human psycho-accoustic behavior is also, by definition, impacted by opinion.
So, I double-dog dare you to sit in a '93 - '96 Jaguar XJ-12 with the Kenwood audio package and tell me that it doesn't sound good. Or, listen to some Crown equipment running through great speakers. Distortion "free" audio with tremendous dynamic range sounds great!
So, back to the subject at hand:
My OPINION is that, given that tube audio does tend to be colored, different tubes within a given make/style MAY indeed sound the "same" if their -dynamic- matching and microphonic responses are within reasonable tolerances. Other makes that happen to fall within those tolerances will too. However, there are outliers in every group that just don't quite match up. To some folks, these MAY indeed sound different.
But, that being said (typed..), it does not make good sense to then insist that all tubes of one make or style sound better than those of another. One person's tastes will not precisely match another's. Some may like the (hypothetical) hint of ringing around 100 Hz caused by double-halo getters while others go more for the touch of (again, hypothetical) mid-range/ultrasonic IMD caused by side square getters.
So , I guess my point is that, barring true linear-region (read "relatively quiet") operation and without effective isolation from accoustic coupling (microphonics), all tubes color sound. How they do so and who thinks what of the end product(s) are a very open-ended pool of variables.

Which 6L6s do I think sounds best? The ones running properly biased and with little to "no" high-order harmonics or IMD. I'm OK with 2nd or 3rd-order harmonics in tube amps. It makes vocals sound good. I learned this while testing audio in accoustic chambers at Tandy. Do I care what brand/style? No, I'm all about signals. I can curve trace two different styles and get matched pairs that you won't be able to tell apart. I can also pick out two same-date-code tubes from a given maker that do sound (almost noticably ) different.

BTW: Did you know that the average consumer confuses clipping with a "loud" sound? RS had a -minimum- distortion requirement of 10% by 3/4 rotation of the volume control for all but their (re-branded Pioneer) "Optimus" line. how embarrassing it was to have to test that schlock!

Hmm, interesting. Th notion about microphonics is something to think about. different mechanical parts of the tube would have different resonances. Mechanical resonances can be quite sharp.

This , of course, assumes that the tube amplifier is within range of the speakers to have this "effect". Which I believe most are.

Interesting the comment William made about his Electro-Harmonix EL84s sounding like someone turned the treble control down a quarter turn. Bias? microphonics? Hmm... it is interesting indeed. something like that I'm sure I would notice.

Anyhow, I'm not saying there CAN'T be a difference, I just want to understand how and why as many audiophools describe their different tubes like fine wine.

-Steve

I like metals because they are usually cheap, but I like the look of an 807 or a 6L6G the most. The 807 is just a neat looking tube, big shouldered bottle with a plate cap. It looks like a serious piece of work. Metal tubes don't look good, but most people don't seem to desire them so I can get them for prices mere mortals will pay. I also have some of the Soviet 6L6 equivalents as a spare for something. They seem to work OK as well.

Just one more thing (a la Columbo,) about new production tubes. They need to be 'burned in' for 20 hours or so because I am convinced this step is being skipped or shortchanged at the factory. Same may or may not be true for used tubes left sitting somewhere for decades. Then pass judgment.

IMHO circuitry and components play more of a role in delivering sound (source and speakers being a constant.) Years ago I built a couple of RIIA preamps based on high quality schematics from yesteryear, and rotated the same tubes between them to find out which was best. Of course I used a couple of teenagers who can actually hear as a judge. I then subtituted other specimens of tubes of doubtful lineage and mismatched but not defective. Same results.

None of us could either tell whether the near unobtainium EL37's, RCA 6L6GC's, or Shuguangs were playing through my Fisher 70 monoblocks. This topic will rage on for a while, I'm sure.

By the way, some beautiful craftmanship shown here, none of my stuff looks all that good. Hats off to you Ladies and Gentlemen.

Teenagers think that ipods sound good, I hardly think they are objective when it comes to sound

+1




+100!
That's mind blowing work. And I've built a good bit of equipment in my time.