What amp / int. amp would you still like to try?

Well, given the first two replies, I feel that I must comment. I am in the process of selling my amp (Atma-Sphere S-30 Mk III) and preamp (Messenger) and purchasing the VAC Phi Beta (directly from VAC...the last one ever produced).

Curriemt11

what is it that you hope to improve on regarding the Atmosphere?

I'm a big believer in amp/speaker synergies. So it's fairly useless to talk about amps in a vacuum without considering what they're driving.

For instance, the Atma-Sphere S-30 is said to be a heavenly match with Audiokinesis speakers. So maybe a speaker switch is a better bet than an amp switch.

Similarly, the Quad 57's sound fantastic with McIntosh MC225's (my dad's setup). When I had some later Quads (63's) they sounded extra nice with an OTL Transcendent Sounds amp. And quite good with a lowly Dynaco ST-70 too.

On the other hand, my Maggies sound too laid-back with McIntosh, but really come alive with an Innersound ESL amp.

I extensively auditioned a pair of Green Mountain Audio Calypso's (GREAT speaker), and those were nicely driven by a VAC Phi integrated.

My point is that the amp technologies need to match the characteristics of the speakers to obtain maximum sonic benefit. So it's helpful to know not only where you are going with your amp choices, but where you are coming from, and the speakers that are your partners in the process!

This is very true and a good point. You can never overlook system/room synergy in building a good system or the synergy between amp and speaker.

Even though I realize its all system synergy, whenever I make any system change, I always tend to think about one component change at a time. Any more than that becomes too confusing. When I make the one change, then I can easily evaluate the results. After that, if the synergy between spkr and amp isn't there, I can then think about changing speakers.

Naturally, if I'm radically changing spkr designs, from a high efficiency speaker to a low one, then I'd also have to change amps as well.

Over the years I have heard representations most of the successful analog amplifier designs. I would like to hear all the digital amp designs. So far I have heard a Spectron, a Tact and a Bel Canto, and have been very favorably impressed with the latter two (perhaps our sample of the Spectron was defective). As seductive as tubes are, they "color" and fog the sound, while transistors add noise. Digital seems to have the potential of doing less harm. Whether that has yet been achieved is another matter.