George kindly let me have his AVC for an evaluation in my system these days. It was a nice chance to meet him in person. He is indeed the great man one would imagine following his contribution in this forum. He already has covered the chapter "measurements". I can only try to put my listening impressions in this post. My system is completely diy from source to speakers so this humble and subjective review should be valid only compared to others.
So, let's start from the negatives -but are they?- as George himself spotted. The crosstalk is there, I could verify when I searched for it but on no account affects the stereo image and the soundstage orientation. I think it would be eliminated if it's built in a bigger chassis. George knows better. Regarding the bass boost, I think I could hear it, but it's not the big difference one would hear from a tube amp compared to a solid state. And is definitely welcome, at least from my open baffles.
From there on only positive impressions. Besides a very nice assembly, it's also a joy to use. It doesn't add noise at all, it has fine gradual steps and most important it matches to everything literally. No matter what source and load impedance, it will provide a useful range to adjust. No struggling with Ohm's law here, just plug and play.
Sonically, is very interesting too. I had compared it only with the digital volume control -default by decision in my system. It doesn't sound the same with all kinds of amps. With my KT88 PP -not the typical tuby sound one would expect- it makes no difference. AVC and digital VC same thing! In my system I rank this high, really! I'm used to a neutral sound to the extend I can hear what an ALPS pot adds. But it is also true that my amp is not a reference. With a class D amp, the difference was audible. The digital VC sounds marginally harsh. The AVC rounds it nicely so it gets very pleasing to listen. By contrast, it didn't make a good synergy with NP Vfet. This amp is already sonically balanced so the AVC made it sound too rounded for my taste. While I can understand the difference between the class D and the Vfet, it's hard to explain why it doen't affect my tubes. Moreover, given that the AVC in all cases was not connected directly to the amps but in front of a preamp -namely Salas DCG3. No other difference was detected regarding frequency response or dynamics.
I can't think of anything else. Generally, very nice work! If I was to move to an analog VC, I would seriously concider this!
That's all! Not sure it makes sence to you. Happy to answer any questions.
Kostas