Power Tube Swap Extravaganza!

[big_teee]

Here's a EL34, and KT77 Tube Shootout.
Another non conclusive comparison of different brands.
The Rivera Amp IMO sounds great.
What do you think?
I really Liked the NOS Mullard , and Telefunken 34s.
Only one I still have a poor opinion of is the EH34s.(I own these and IMO they still sound thin)

[Justin Thomas]

I liked the Siemens EL34s & =C= EL34s for leads... Makes me miss =C= already! Didn&t think the EHs were thin so much as whimpy. I guess I just like bold and in your face but also round and fat. I generally play clean, so I need a tube that does that primarily, and I think if a tube has a great clean, punchy, round sound, it'll do good overdriven. And there's a thing where there's lots of treble, but there's not pain/earshredding slice that some tubes get. The description "tubby" makes sense to me.
The rythm tracks were a little harder to tell apart, but I did like the openers. Again, the EH seemed kind of lifeless. They have a personality, but they're just not assertive - tubes should say "hey! Look at me!!!" I wonder if a lot of these tube companies are testing in complex (multichannel/MV/onboard EFX)
/etc) amps or assuming we're using pedals? Any of them catering to us guitar-cord-three-knob-amp guys?

Dang, makes me wish I could do these with my Fenders - master volume? What's that? A BF Bassman is about as easy as it gets for tube testing! Let's make those power tubes sing and KNOW it's them - there's only one way to get the job done! I'd hesitate with the EL34s, though I guess I should cross-check my PT to see if it's safe. I guess the less other parameters there are to futz with, the more accurate the test, within obvious limits of course. No lectures about variables, please!

Justin

[km6xz]

It would make more sense to reduce the number of variables by assuring the demonstrator does not vary in playing style or volume which was varying quite a bit. If all else is constant, the loudest one is preferred by most people....just ask a salesman in a hi-fi showroom, he can steer anyone into any speaker that gives the highest spiff and commission with slight, loudness setting differences. When we did A/B tests in a controlled acoustic space, (studio A or C in my studio) we re-amped so a passage was recorded flat from the guitar and Z and levels matched to the guitar<>amp interface so it removed the highly variable human in the test that is responsive to the results by way of being in the feedback loop where the output directly impacted the input.
Next, the time delay between samples ruins any relevance of the passage. We need 1 second or less samplings repeating the same wave form, otherwise we are not remembering the sound difference directly by are going by our memory of the impression, not memory of the sound.
Bear in mind that such a test only relates to the exact circuit conditions of the test amp and is not transferable to other circuits. We know the sound differences we hear is the harmonic and inter-modulation products which are largely determined by where on the conduction curve the signal is riding. A signal that stays in the mostly linearly portion of the curve will have similar spectral output but if one tube has early onset of non-linearity, at some playing level it will have much more harmonic content than another tube that stays linear further up the load line intersection. Another amp, with different feedback, different plate Z, different power supply voltage and regulation and different eq will possibly make a different tube shine. In the linear regions of the curves, most amps sound very much alike in their power output section. So it is entirely possibly...probable, that what one person subjectively likes with one tube type for harmonic content with one amp will not be rated by them so highly with a different amp with different operating characteristics.....even of the same model.
considering how inconsistent modern tubes are between samples of the same model, plus all the foregoing, making judgments about the whole range of production in the whole range of amplifier operating conditions, leaves such judgments squarely in the realm of wishful thinking. Luckily we remember our impressions far longer than the actual sounds so we continually talk ourselves into thinking one sounds like we first imagined. Various tests in lab conditions with controlled variables in the field of human perceptions pretty much prove that we really don't remember sound very long but we are very easily convinced about what we remember is accurate, even will large deviations introduced into the test.

[big_teee]

It would make more sense to reduce the number of variables by assuring the demonstrator does not vary in playing style or volume which was varying quite a bit. If all else is constant, the loudest one is preferred by most people....just ask a salesman in a hi-fi showroom, he can steer anyone into any speaker that gives the highest spiff and commission with slight, loudness setting differences. When we did A/B tests in a controlled acoustic space, (studio A or C in my studio) we re-amped so a passage was recorded flat from the guitar and Z and levels matched to the guitar<>amp interface so it removed the highly variable human in the test that is responsive to the results by way of being in the feedback loop where the output directly impacted the input.
Next, the time delay between samples ruins any relevance of the passage. We need 1 second or less samplings repeating the same wave form, otherwise we are not remembering the sound difference directly by are going by our memory of the impression, not memory of the sound.
Bear in mind that such a test only relates to the exact circuit conditions of the test amp and is not transferable to other circuits. We know the sound differences we hear is the harmonic and inter-modulation products which are largely determined by where on the conduction curve the signal is riding. A signal that stays in the mostly linearly portion of the curve will have similar spectral output but if one tube has early onset of non-linearity, at some playing level it will have much more harmonic content than another tube that stays linear further up the load line intersection. Another amp, with different feedback, different plate Z, different power supply voltage and regulation and different eq will possibly make a different tube shine. In the linear regions of the curves, most amps sound very much alike in their power output section. So it is entirely possibly...probable, that what one person subjectively likes with one tube type for harmonic content with one amp will not be rated by them so highly with a different amp with different operating characteristics.....even of the same model.
considering how inconsistent modern tubes are between samples of the same model, plus all the foregoing, making judgments about the whole range of production in the whole range of amplifier operating conditions, leaves such judgments squarely in the realm of wishful thinking. Luckily we remember our impressions far longer than the actual sounds so we continually talk ourselves into thinking one sounds like we first imagined. Various tests in lab conditions with controlled variables in the field of human perceptions pretty much prove that we really don't remember sound very long but we are very easily convinced about what we remember is accurate, even will large deviations introduced into the test.

You Engineer types, are making way to much out of a couple of simple tube checks and videos.
It is what it is, and no more. Have fun with it.
If you listen to enough of these simple vids.
Us lay folks can get some ideas if you want to try or don't want to try a particular tube set.

[daz]

This perfectly demonstrates what i have said forever. I know what some will say when they read what i'm about to say, but i'm not going to debate what i know for a fact is what i hear/feel or don't hear/feel. I'm really burned out on that debate and it's useless. But i wanted to post just to put fourth a idea that for me is fact but i assume most seem either to be unaware of, or maybe it's just me for who this is the case.

So wwhat i was getting at is that when you hear someone else playing, and particularly when it's not your exact amp and guitar, hearing differences in tubes for example that you easily hear when YOU are the one playing and it's YOUR gear is nearly impossible. For example, i literally would bet you my life that you could blindfold me and let me play my amp with my guitar and swap tubes back and fourth between say winged C and EH and i could tell you every time which i was playing. The difference to me is so obvious it's impossible no to hear/feel it. That said, in that video i wouldn't bet a nickel because i may possibly be able to tell if you blinfolded me and played each over and over for an hour, but i seriously doubt it.

I believe that when arguments start here regarding what things are or aren't possible to hear like that that cap thread, most people are looking at it from the perspective of being a listener like with this video and NOT in the context of YOU playing YOUR gear, and furthermore gear you've owned long enough to know it like the back of your hand. In the latter scenario i can hear things EASILY that i couldn't hear with a gun to my head when played by someone else on thier gear. In fact, i'll go a step further and say MY extremely familiar gear in someone else's hands would also have me guessing wrong most of the time !

The difference in tubes in that video, and by the way i've owned or now own a good 1/2 of them or more, all sound about the same to me !

[big_teee]

This perfectly demonstrates what i have said forever. I know what some will say when they read what i'm about to say, but i'm not going to debate what i know for a fact is what i hear/feel or don't hear/feel. I'm really burned out on that debate and it's useless. But i wanted to post just to put fourth a idea that for me is fact but i assume most seem either to be unaware of, or maybe it's just me for who this is the case.

So wwhat i was getting at is that when you hear someone else playing, and particularly when it's not your exact amp and guitar, hearing differences in tubes for example that you easily hear when YOU are the one playing and it's YOUR gear is nearly impossible. For example, i literally would bet you my life that you could blindfold me and let me play my amp with my guitar and swap tubes back and fourth between say winged C and EH and i could tell you every time which i was playing. The difference to me is so obvious it's impossible no to hear/feel it. That said, in that video i wouldn't bet a nickel because i may possibly be able to tell if you blinfolded me and played each over and over for an hour, but i seriously doubt it.

I believe that when arguments start here regarding what things are or aren't possible to hear like that that cap thread, most people are looking at it from the perspective of being a listener like with this video and NOT in the context of YOU playing YOUR gear, and furthermore gear you've owned long enough to know it like the back of your hand. In the latter scenario i can hear things EASILY that i couldn't hear with a gun to my head when played by someone else on thier gear. In fact, i'll go a step further and say MY extremely familiar gear in someone else's hands would also have me guessing wrong most of the time !

The difference in tubes in that video, and by the way i've owned or now own a good 1/2 of them or more, all sound about the same to me !

I agree with what you said.
My intent was not to get a highly technical debate about process, or even which tube is the best.
I put that in each post.
It seems on here no-one can have fun and listen and respond.
So with that said, if I do this again, it will not be here!
Everyone gets too defensive, instead of listening commenting and having a little light hearted fun!

[Steve Conner]

I design scientific instruments for a living. I take the same approach to all the DIY audio gear I build. I try to understand the theory of the circuit and use it to predict how all the different parts will affect the sound. I've done a lot of synth programming and sound design, I know the theory of Fourier analysis, and from that I learnt the correlation between a waveform on a scope and what it will sound like. When I'm developing a circuit, I listen to it critically and try to square up what I hear with measurements. If I think I heard something that I can't measure, I'll measure some more. So far nothing has escaped.

I use all this stuff to make something that I hope will be reliable and good-sounding. But when it comes time to play (or listen to a stereo) I try to forget it all and just enjoy the music. I'm not going to ruin a jam session or an evening of listening with endless tube swaps.

Could I (and you) hear a difference between all these tube types? Probably. To address Daz's point, I'd set up a test where you could switch between tubes while playing, in ABX fashion so you didn't know what you were playing.

Would I bother doing the test, probably not. I wouldn't put too much store by a non-blind test with someone else's lossy compressed YouTube audio.

[J M Fahey]

Same here.
I would put a row of tubes on a table, plug them one by one and play.
Period.
If I think I like one of them over the others, I repeat the test.
Or try to weed out the worst (although differences might be very subtle, if any).
And then would make it quite clear that what I have heard applies to this set of tubes, on this amp, today.
Extending what I heard from any particular tube to all others of the same brand, is stretching things too much.
Doing so after listening to somebody else through a You Tube video, using an unknown amp, even more.

Note for the technophobes: I have mentioned not a single piece of Lab equipment, nor Datasheets, Math or Physics

[daz]

And then would make it quite clear that what I have heard applies to this set of tubes, on this amp, today.

Exactly. I never cease to be amazed by the way things can sound so different with nothing changed but the time....a few hours or days, even sometimes minutes later and you can seem to be playing a different amp. This is why i A/B things ad nausium if the difference isn't extremely obvious. And then i A/B them again at a later date numerous times to eliminate the dreaded "great one day, mediocre the next" conundrum. many things i have A/B'd even a year or 3 down the road to make sure the conclusion i came to still rings true to my ear. I find that when A/B'd enough times over the course of days/weeks/months, things that were subtle begin to become much less so and the differences become undoubtedly clear. The reason i go to such anal lengths is this....one subtle thing is no big deal, but in designing my main amp i have run across many things like that which when added together mean the difference between my amp being a very good amp are a incredible one. But you must be positive which way is better with each design consideration because if you make mistakes you may be adding together a bunch of negatives too. It's really the only way to end up with a amp that stands out as unusually good, because no one thing is going to get you that. It's all the tiny things combined that work together that put it over the line from great to amazing. And incessant A/B'ing is the only way to determine which way to go on subtle tweaks. But they ARE important which is why when someone tells me "why do you bother with such unimportant subtleties" or "the audience won't hear it" and other such simplistic attitudes, i just roll my eyes. I have my reasons !