Van Alstine?

Not much in carefully controlled listening tests from me, I'm afraid. My Linn LK1 preamp died of a control board fault after about 18 years of service and I replaced it with an Audio by Van Alstine OmegaStar PAT-5 (purchased used directly from AVA). Music was just as enjoyable (LP12/Ittok/LK2/Saras were the other components), which I couldn't say when pressing an NAD 1020B preamp into service when the LK1 was on the fritz.

More recently, I replaced the LK2 poweramp with an AVA Insight 240. System configuration was a bit different, with the LP12 sharing time with a Well Tempered Record Player (Grado cartridge and phono stage) and Vandersteen 1C's replacing the Saras (driver failure; no replacement parts available). Compared to the LK2, the Insight 240 retained what the 1C's were capable of with respect to pitch relationships, rhythmic coherence, and dynamics while adding a bigger, deeper soundstage with better space between instruments and more stable and precise imaging.

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).