VTL Tetrode/Triode

I think I need to slightly amend a couple of the (mis)impressions I seem to have left from above.

Hgabert refers to agreeing with me that "with tetrode...the frequency spectrum is flatter". Yes, tetrode could be called 'flatter' in that it sounds more extended, both top and bottom, but I said above that triode sounds more neutrally-balanced to me through most of the audioband, including all of the midrange. To me, tetrode is less flat than triode here, which is where it counts most. Questions of ultimate tonal balance, however, are quite dependent on partnering gear and choice of input tube.

Piezo says he agrees with me that "tetrode...has more purity and naturalness". Actually (except for the part I just omitted about tetrode having greater dynamic range, which is true, and which he stipulates to), that is what I said about triode, not tetrode - which generally seems a bit less 'pure' and 'natural' than triode, for reasons I speculate some about above - and in that respect we really do agree.

Doh! I did indead mis quote you, but i do agree, as you noted that triode is more natural and pure. It appears that I forgot to add "triode" at the appropriate place.

As to our other observations being 180 out, that's strange because we both are apparently hearing the same things but in the opposite modes and have a similar overall impression of the two modes (ala triode being more natural). The question that arises is: are there system dependancies that are driving our observational differences or are we describing the same thing differently. If the latter it would seriously cause one to take all reviews with an even larger grain of salt due to the subjective listening impressions being overprinted with imprecisly defined descriptions. Just some philosophical head scratching.

This also reminds me that we audiophiles are using a particular definition when it comes to the word "natural" - one where we are mostly talking about matters of texture and tonal and harmonic balances, and here the word applies best to triode. If we expand on that definition a bit to consider other aspects that could also be described as being more so, then I would say that tetrode has the more 'natural' spatial presentation, dynamics and articulation, and ability to resolve fine detail. But we normally use other words to denote realistic performance in these areas.

I'll also mention an analogy I've used before to sum up the different impressions I get from comparing the two modes: With triode, I often feel as if the performance is less 'electronically' rendered than with tetrode, but also that I'm listening to it at some remove, sort of as if I were in the next room - while in tetrode, the performance sounds slightly more like an 'electronic' artifice, but also as if it's a performance that I'm more in the direct presence of, in the same room with if you will. Or put another way, with triode I more feel like I'm hearing the real thing but also that I can't 'touch' it, and in tetrode I feel more like it's embodied right there in front of me, but that it's less quite like the original thing and more of a slightly 'off' clone. The choice is like looking through a window at your very own mother (triode) vs. exchanging a hug with her replicant (tetrode). I guess people buy even better amps (presumably - hopefully, for me - at a higher cost) so the two qualities can be combined to an even larger degree than these amps can manage strong glimpses of in the respective modes...

I think where we are seeing things different is in the presence part of our descriptions because we both agree that triode provides the most realistic rendering of the music.

For my system and ears the triode mode conveys much more detail and recorded room ambience, more direct palpable presence of the instruments than in tetrode (small group, preferably acoustic based music is forming the basis of this comment). Listening to Keb mo i feel that i could walk around him while listening to triode, not so defined in tetrode. For me tetrode tends to provide the wash of sound that you attribute to triode, though it tends to have more body/fullness, just not as pinned down and accurate..the slightly off clone that you describe.

Seeing that we agree on a number of our observations my guess is that the way our speakers (and rooms) deal with the different modes (and resulting drop in available power in triode) may play a significant part in our differences

What are your speakers/cables? To reiterate, I'm listening through Thiel 2.2's and either Satori or Au24 cable (though these impressions were formed only with the Satori, as I'm still evaluating the newer-to-me Audience cables).

Anyway, I'm not sure I can put a tag on which presentation is 'most realistic' so easily. I think it depends a lot on the recording and type of music. As I said above, in general I find tetrode more realistic in terms of qualities I would call 'physical'. But I think triode is more 'accurate' in its tonal and harmonic presentation. I've had some recent success in transforming the tetrode tonal balance more to my liking by both changing input tubes (the previous ones had become microphonic, and were brighter) and by placing tube dampers on them. However, I'm not quite done sorting this all out yet, because I've also gone from Svet 6550C's to EH KT-88's, and on top of that I haven't yet carefully evaluated again the tetrode/triode question with all the new tubes in place. Not to mention that I'm auditioning these speaker cables, which sound perhaps more transiently accurate but less warm than my reference, and I also just had a tweeter and crossover resistor replaced and that speaker is still breaking back in...it never ends :-)

Anyway, yes, my physical impressions are pretty much the opposite of what you describe in your second paragraph above, so apparently our 'clones' are 'slightly off' in different ways. Where you say triode gives you more detail, room ambience, palpability, walk-around transparency, and is more pinned-down in space, I feel tetrode does all those things better, with triode being the mode giving more body/fullness (if less extension and tautness). It's enough to make me wonder if our mode switches are wired-up the same way or if one's reversed! But I guess I envy anybody who's come to the comfortable conclusion that one mode is usually best for them...at some point here I'll revisit this question with the new tubes and post my findings.