Van Alstine?

Jrtrent, thank you for your thoughtful response.

Tgrisham:

Please read my posts above. Hidden in the middle is a comparison of the AVA Ultra 550 with Plinius SA100III, Plinius P8, Sunfire signature 600, and the Wyred 4 Sound ST-1000.
Unless I can establish reasonable certainty through blind testing that I am imagining rather than hearing real differences between amps, I will continue to go with the belief that that AVA model, almost the top of the line, is inferior in vitality and body to those other amps. Even the W4S, at roughly the same price, appeared to me much more exciting and realistic than the AVA.
This is dealing with two questions at once: Are there really differences?-- and, how does the AVA Ultra 550 compare to other amps?

Yes,

I did gather up the information from before. And it did speak to my original question. Unless there is something spectacular about the AVA amps, then I see no reason to change. I do like my Bel Canto M300s but was interested in simplifying and going with a transitor stereo amp. On the other hand, the M300s do many things well and for now I intend to keep them. I strongly considered the W4S amps but at present it would be a lateral move and I would only do it to step up to 500W/1000W, and I most likely have no need. The W4S amps do have a higher input impedance (60,000 vs 10,000 via RCA) but my pre-amp seems to have no trouble with them. I am still learning. I am looking to simplify when I can, such as going to computer based playback. For the money, getting a W4S DAC would be a better move than a different amp. Thanks again for your info.

Rpfef, I'm surprised the W4S drove the Hawks without any real problems. As you said, and as we both know, they are a very tough load that hits under 3 Ohms for a good part of the low end. Digital amps typically don't do real well with a load like this (yes, I've heard other digital amps with similar loads).

I have owned Van Alstine equipment for 30 t years. Currently have Insight 440 Amp, Insight Preamp and DAC. Also use an older FET Vavle Pat 5 pre-amp in a different system. The stuff sounds great. The pieces are rugged as the mountains. Frank Alstine is always willing to answer questions and suffers this fool with patience. You should also be aware that upgrades are available and seems reasonably priced. Can't recommend highly enough.