Thoughts on the First Watt SIT Amps

Hi Phil,
That was an interesting and informative read(as always). Compared to your Audion SET amps(845 and 300b) would you say the SIT-1 is'more'resolved, nuance,faster and extended(Srajan found these qualities superior with the SIT-1)? Calling it the best SS amp you`ve heard is high praise.
Regards,

213cobra,

Good write-up! I couldn't agree more, that the SIT amps could uses a little more power and headroom. Did any of the SIT amps exhibit any noise or crackling sounds that you could hear through the loudspeakers?

I heard one of the SIT amps recently, and it sounded very good, fuller and richer than other First Watt amps also demo'd.

One concern I might have is how many of these SIT devices exist. It's not the same as availability of NOS tubes.

>>Did any of the SIT amps exhibit any noise or crackling sounds that you could hear through the loudspeakers? <<

Both SIT-2 and SIT-1s were dead-quiet in any practical snese, in my two encounters with them.

Phil

>>...would you say the SIT-1 is'more'resolved, nuance,faster and extended<<

Audion amps, whether SET or Push-Pull have a uniquely fast and transparent aural fingerprint, so I don't hear the SIT-1 as "faster" than the amps I prefer. In fact, in some respects I'd say a conventional Pass transistor amp sounds a bit faster than does the SIT. I also don't hear it as able to reveal more nuance nor is it more resolved. As to the latter, let me say that I don't hear the Audion SET amps leaving anything out that I can otherwise hear through the SIT-1. But the presentation of resolution is asserted more by the start of the note than the finish, if you understand my meaning. The SET amps lead a little more softly and finish with more "glow" or decay. But the momentary event is fully present through either amp. Will some people *perceive* the slightly softer leading edge of SET as less resolved than the SIT solid state amp? Maybe, and I can understand why. But that's not how I would rank the two different presentations.

As for extension, in the room I listened in, with recordings I am familiar with on my own systems, I did not hear deeper bass information with the SIT-1 (nor the SIT-2) than with SET, but the definition and agility of the sub 100Hz region is superior on the SIT amp -- either one of them. I'll venture that Dominance's extra measure of dynamic ease over Definitions is also apparent in the downfiring sub, by a discernible margin. So in a larger room with much more power, that speaker can deliver bass authority that might be mistaken for more "range," but where it might dig deeper I think that's relevant on very few recordings. As for the SIT amps, I haven't heard deeper-than-SET in either case, but the SIT amps reproduce bass more precisely, which is good.

On the top end, the Radian 850 is exceedlingly resolved and smooth at the same time, but it is not a hyper-extended tweeter for the ultra-sonic obsessives. Both the Audion SET amps and the SIT amps have top end response exceeding the flat response of the tweeter. Again, the presentation of top end information is different, but the presence of it is the same. I have this debate all the time with people who believe they like p-p tube or ss amps over good SET. With the Audion amps, all the information is present on top, that you get from the SIT (either one) but the sonic profile is somewhat different.

Where things get dicey from a value standpoint is: would I choose a single-ended SIT amp with tunable bias over a very simple-circuit push-pull tube amp like a Quad II Classic or Quad II-Forty, at $3k - $4k for the tubes and $10k for the SIT monoblocks? I would definitely pick the Quads over the SIT-2. The SIT-1 is a tougher call if cost is discounted and only sound is the selector. SIT-1 has the tonal unity of SET, which even the simplest p-p can't quite duplicate, but the simple Quads do better on dynamic heft and deliver the whole note with a minimum of crossover notch grunge. Not so with more complicated and massed-push-pull mad-power tube amps. With efficient speakers, I'd take SIT-1 monoblocks over any modern overwrought push-pull tube amp featuring more than one pair of tetrode or pentode tubes per channel.

Phil