VTL Tetrode/Triode

I feel like a complete fool, but I recently plugged each mono block into its own dedicated outlet, and man, what a difference! Now tetrode and triode sound a lot more alike, and I actually prefer tetrode for 80-90% of my listening.

Tetrode sounds perhaps "grittier," but more real! I certainly agree with Zaikesman that with tetrode there is more extension, and that the frequency spectrum is flatter. This is important to me, as I can lean back, listen, and there is nothing missing (highs, mid-range, lows, everything is there, and nothing jumps at you - - just like in the symphony hall). The soundstage is incredibly linear and extends well beyond the speakers to the left and right (but is also deep).

Conversely, with triode, I feel that the midrange is accentuated. Vocals are clearer with triode, yes, but over the long haul, it's not as involving (it get's a bit "glassy" and the soundstage is smaller than with tetrode. Actually, the soundstage with triode stays beween the speakers, and it's more "curved."

My experience is that the db difference for equal loudness is maybe 1.2 to 1.5 (i.e., triode needs to be set at 1.2 to 1.5 db higher than tetrode, which is also easy to do with my preamp (Levinson 380s).

I agree that it would be nice to keep tetrode the way it is, but also have triode's better harmonic structure and inner detail. Why can't VTL do that? Hopefully, they will at some point in time.

Interesting result on the outlets - are they separate dedicated lines too? I guess your 450's in tetrode were pulling too much from the wall to share nicely. My 185's probably don't - I have them plugged into the same Power Wedge Ultra PLC I use for all my gear combined, with its lone cord feeding from the single available outlet. I haven't minded, but I may find an improvement if I ever re-situate to allow plugging into multiple lines or outlets (then again, maybe not - hum can often become worse in such installations).

Freaky that you have the same preamp as me - how many guys could be running Levinson pre's into VTL's? Our slightly different impressions of the relative tonal balances between triode and tetrode could be because of our different speakers, and also because of different tube and cable choices. I've recently done some switching in the tube department, you can read about it on this archived thread.

Yes, the outlets are separate, dedicated lines @ 20 amperes each. It is funny we have the same preamps. My speakers are B&W 803 Nautilus, hooked up with Transparent super Bi-cable speaker wire. I also use Transparent super interconnects, and my digital source is Mark Levinson 390s. Good sounding system, very lively, I like it now (but it took me a while to get there)!

BTW, your thread is interesting, thanks!

Zaikesman, you description of the physical qualities of tetrode verses triode are exactly what i would say...only completely opposite. I agree with you where you say tetrode has a greater dynamic range and has more purity and naturalness. But i find triode to be more detailed, have a more focused images, tends to reveal more high end detail with a little less body, all characteristics you attribute to tetrode. Interesting.

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.