Sonic qualities of SET output tubes?


Can you readily identify a 300B, 2A3, 805, 211, etc., amp’s sound with your eyes closed most of the time?


If so, I’sure would like to hear from you.


Amplifier design and the technology utilized within its confines decides the ‘voice’ or influence it will yield as much or more so than merely the output tubes the designer has chosen to use.


I get that part emphatically. One must hear the amp regardless the type of output tube technology on hand.


And yes, some Pentodes and Tetrodes are used as Triodes but are not indeed triodes by their specific architecture. That’s OK, just focus on their use as Triodes herein, please.


There are however certain tube types, irrespective of vintage which have basic undeniable sonic colors or characteristics, apart from their electrical aspects which keep attracting people to amps which use this or that tube in its output stage.


Some love 211s. some adore 300Bs. Some love EL34s configured to run as Triodes. I have an affinity for the latter. So far anyway. This topic could change my mind.


Has your own experience informed you what this or that output tube’s natural flavor regularly announces itself to be so you can have a reasonable expectation of its general presentation?


What sonic attribute continually attracts you to a particular SET tube design, 300B or some others?


Or, conversely, what is it about the sound that would bring you to covet a 211 amp over a 2A3, for example.


Why as another example, would you pick a 2A3 amp over one using 805s or 300B, 211, etc. or vice versa?


Removing ‘vintages’ and electronic or electrical qualities from the argument, what sonic attributes for the more popular S.E.T. amp output tubes have you determined seem to persist in their particular DNA?


I’m asking for input from those SET tube devotees to lend their experiences and knowledge on the subject of what tube sounds like what irrespective of the SET application, generally speaking.


My goal is to try getting a better feel for which SET Tube amp design, if any, I’d want to pursue and possibly invest heavily into going forward as the soul of a new system.


Tremendous thanks to all!

blindjim
Blindjim…there’s an interesting Youtube video of Had talking about his amps with a little tour of his shop, and a several hundred page discussion of his "post Cary Audio" builds on Audioaficianado.org. He sells his stuff exclusively on Ebay (or you can order things directly from him by contacting him through his Ebay address, although he’s pretty busy so good luck with that..) although he does build headphone amps sold through Moon Audio (recently positively reviewed by Absolute Sound). You also can look up his sales history on Ebay to see what he’s sold recently. Otherwise he’s a small potato in the current audio geek component manufacturing  scene (I assume, having no idea how many amps for example Atmosphere sells) , but I personally think his amps are an utter bargain in the world of hand made sonic excellence…Shindo Schmindo!
wolf_garcia > …Shindo Schmindo

blindjim > lol. Rotflmao. Lovely. That was great.
I’m supposing just Goog his name with the AA or Ebay suffix.

I’ll sure try.

For sure there are a goodly bit of low powered glass amps about. Way more beyond SET in PP land that acquit themselves quite well.

Hi Larry,

I have always felt that really good amps, regardless of type, sound great at low volume levels and you really don’t have to crank up the volume to get the juices flowing. A good SET amp will be satisfying at a much lower volume level compared to most solid state amps. The same is true with good pushpull and OTL amps. But, if you are someone who loves to play music at really high volume, a SET may not be your first choice. So, they are often not thought of as being well-suited for loud rock music.

From my own experience, I think SET amps work well with all kinds of music. The only kind of music where I really wished my SET would deliver more power involved large choral pieces without any kind of instrumental accompaniment (e.g., Rachmaninov’s "Vespers"). For some reason, this sort of music is a challenge even when the overall volume is not that high (voices become muddy and the swell in volume is compressed).

I think your experience with SETs and large choral pieces says more about the amplifier and possibly the speakers.

In my comments below, I want to eliminate single driver systems (e.g. Lowther, Fostex, etc.) from this conversation. Single driver systems can flatter small, intimate works, but they get confused when listening to musically dense works (opera, massed chorals, large symphonic, etc.) . In my experience, this can get to the point where you stop listening to this part of your record collection.

I’d like to talk to this low level-listening phenomenon from a system building perspective. One of low power SET amplifiers’ drawbacks is also one of their virtues - that they work best with high efficiency speakers. Of course, this is a virtue that can be exploited by higher power amplifiers as well.

High efficiency speakers (especially horns) in general, have a lower noise floor which contributes to their high resolution at low listening levels, to the point where the experience can be spooky in comparison with your run of the mill, 5-figure, cone and dome system powered by an arc welder. Many electrostats do this as well, but for different reasons.

High efficiency can also benefit high SPL performance as well (ask any pro-sound guy).

Low efficiency means electrical energy is converted into heat, which in this case means the voice coil. This in turn, can affect the crossover, and no high-powered amplifier can compensate for this.

Of course, at the end of the day, preferences are in the context of the perceptual framework of the listener, but (anecdotally), I’ve never heard of someone going back to low efficiency speakers once they’ve had them. It’s a one-way door ;-)

Cheers,
Thom @ Galibier Design





Thom @ Galibier Design > …. One way door.

Blindjim > although I’m not Larry, I want to thank you for the insights. I feel they are frank and as such valuable.

I get it now. The musical genre is not the issue to worry about with itty bitty powered rigs. Why I felt it was amazes me. Fine. .live and learn.

Thanks for the feedback on single driver speakers. I had summarily dismissed them already as a possible solution.

The overwhelming advice here says the ‘horns’ have it as the usual suspects for mating to triodes when feasible. Now, I’ve just gotta find those affordable horns and SET amp (s) to begin acquiring some EXP.