Wow, this is an interesting turn of events. I actually emailed Rich a week or so ago and he asked that I call him, which I may do today. However, I believe Rich is now located in Nevada, not Long Island. Interestingly, I have read from someone on Audiogon that Tube Research Labs go very well with Apogees. Having said that, I'm a bit disappointed the NAT Symmetrical won't be a great fit with the Centaur Majors. How Marc describes his NAT gear is EXACTLY the sound I'm looking for!
You and Bonzo were kind of talking past each other because he was mostly (and incorrectly, IMHO) saying that big SETs from NAT don't work well with Apogees and you were asking about their preamps.
I don't know if your budget extends to their current, significantly more expensive, models but the Symmetrical is a good sounding preamp, rich and big boned but still with very good resolution. The word on the street though is that the Plasma was better, specifically the older Plasma before they switched to 6N30P tubes. I have one of these older Plasmas and it has 6 x PCC88 per channel! I think they are all in parallel to act like a single big triode. It is also somewhat rich, but not overly so and has dynamics that are thrilling. Transparency and imaging/soundstaging are also superb. It does need about 45 minutes of warmup time to really open up but that is not so unusual in the high end world. I doubt that there is a better preamp on the market for the price. When you look inside you see the quality: Truly dual mono with big power transformers, large caps, tube rectified and tube regulated and lots of SS regulators for those filaments. Well designed and executed I would say.
i haven't heard the latest and greatest NAT preamps but they might be killer but also the price is no longer the bargain they once were.
As for amps, if you are curious about SET amps then you should give NAT a try on your Apogees...I think it could work very well despite the advice Bonzo has given you...I know it sounds quite good in fact. Be aware though that the new SE2SE is using GM70 tubes now and not 211s. Sonically it will be different than Marc is describing.
I have heard the exact amps Marc has (2 different versions in fact) as well two different SE1s and the mighty SE3 on Apogees and other speakers. All were powerful, transparent and with holographic imaging. They were not particularly warm sounding, unlike the NAT preamps I have heard, which are all a bit warmish. I also found that they were a bit lacking in the ability to transport me emotionally...not sure if that had to do with the rest of the systems though. In addition to the NAT Plasma, which is full of emotion, BTW. I had the NAT hybrid, the Symbiosis SE. That one was a pain as it took over 2 hours to warm up properly and THEN it would sound deliriously holographic but before that it was a bit too stiff in the hips and I just could wait 2 hours every evening for it to warm up.
KR delivers really good sound on all kinds of speakers. The other one to consider is Aries Cerat. The Diana Integrated is a beast, sonically as well as physically. The new Diana Forte, at 60 watts, will drive the hell out of the Apogees for sure and is more transparent and has more dynamic slam than any of the others mentioned here. Have a look also at the Incito preamp. It is about 8.0K new and the design is very promising.
