In the past I've been a big downer on the topic of a single 200iQ stereo, versus a pair in mono. I have to revise that opinion. Since the absolutely stunning Master 300's took over my main system duties, I've been playing the 200iQ's in a second system. This 2nd system is smaller and scaled down. Even allocating floor space for a pair of 200iQ feels overcrowded. And then, we have the Russian tube supply issue - I'd much rather rap on a quad of KT88/KT120 at a time, versus an octet!
So given that, I've been experimenting all over again with amps in this 2nd system (I've previously experimented with all these same amps in the main system):
* Rogue Apollo Dark (high power PP tube, 250 Watts/ch) - Best bass and dynamics. Good treble. Worst midrange - always a little dry and sterile, no matter what you do (tube rolling, triode mode, etc). In the past, this midrange didn't bother me as much as it does...now, I just can't get over it. Still a great rock & roll amp! Or for large-scale orchestral (not that I play it much) - the dynamics are stunning.
* Phison A2.120SE (Danish boutique, solid-state class AB 120 Watts/ch) - Good at everything. Very close 2nd in bass to Apollos. The Phison's bass is a little tighter and quicker; Apollo's bass a little fuller and more satisfying. Midrange done right for SS, here - it's even sweeter than the tubed Apollos! Can be a tad bright in some systems (Tannoy pepperpot tweeters can be rough), but not in this one (Tannoy tulip tweeter, even being much cheaper, is smoother).
* VAC 200iQ stereo - Better midrange by far, versus Phison and Apollos. Super sweet. Most holographic, 3D image. Most natural sound - full and satisfying, and with the most detail (except in bass). Bass is a bit soft and sluggish; starts to fall apart a little on hard rock.
* VAC 200iQ monos - Takes the stereo qualities and tightens everything up. Notes are fleshed out with a more weight and solidity; mono also renders cleaner tighter edges without harshness. Bass power and clarity / tightness is significantly improved. However, I STILL feel its bass loses out versus both the Phison and Apollos. I'm talking about hard rock at loud volumes, where the beat is hitting hard and fast. The 200iQ monos also seem to aggravate some room acoustic issues here in certain bass frequencies, whereas the other amps glide through this more easily. Now here's what's interesting - I find the 200iQ stereo might have a more "romantic" tilt to the midrange. Better clarity and detail on the monos for sure but...stereo configuration seems a little more rich, organic and satisfying somehow. You know what - I need to try stereo bi-amping!
* VAC 300 Master monos (only used in main rig) - Compile all the BEST attributes from the above amps, improve them further, and put them all together again. Add some "how did they do that" magic, for good measure. That only begins to express how amazing these amps are! Worth the price (you have to sit down for that part). Single biggest component impact I've ever heard in 20+ years. I haven't even tried a single 300 in stereo mode, yet. I might be in for a good surprise? My speakers are 8 ohms, and like with 200iQ's the 300's mono mode appears to be tap-optimized for 4 ohms (better match to 8 ohms in stereo?). I haven't picked on Kevin yet about the topic of taps for 8 ohm speakers, but I want to.
Anyways - I think a single 200iQ stereo amp might be looking like the winner in 2nd system! VAC sound, especially midrange, is very addictive.