Well, I can't make a direct comparison with my AC-3, as I do not have any My Sonic Lab (MSL) or Air Tight models at hand. However, I do have an Audiocraft AC-03 which was designed by Matsudaira when he was chief designer at that company. This was a low output, low impedance design (0.3 mV and 3 ohms) available until the early 2000's, after which Matsudaira started his own company with MSL. I've read reports that the AC-03 sounds very similar to the MSL Eminent models, even though these later systems have a much improved output/impedance ratio (around 0.4 mV and as low as 1 ohm impedance).
Anyway, when comparing Accuphase AC-3 to Audiocraft AC-03, I would say the Audiocraft sounds immediate, powerful, neutral and very much 'alive' . These are also characteristics often used in reviews to describe the MSL's, so there may well be a strong family resemblance. The Accuphase AC-3 on the other hand has a more refined sonic presentation. It has extended bass, a warm glow in the midband and a smoother high register. Very beautiful, but also less exiting. It seems best suited to orchestral repertoire, where the 'mid hall' perspective allows the music to breathe. The Audiocraft's 'front row' perspective works better with more rhythmic material. So they complement each other quite nicely.
Caveat: the Audiocraft and MSL systems reflect Matsudaira's own sonic priorities. But OEM work for other companies may yield different results and in this case perhaps closer to the Accuphase 'house sound', if such still exists. So perhaps the AC-6 might sound like a more polite version of the MSL. Still with me?
Anyway, when comparing Accuphase AC-3 to Audiocraft AC-03, I would say the Audiocraft sounds immediate, powerful, neutral and very much 'alive' . These are also characteristics often used in reviews to describe the MSL's, so there may well be a strong family resemblance. The Accuphase AC-3 on the other hand has a more refined sonic presentation. It has extended bass, a warm glow in the midband and a smoother high register. Very beautiful, but also less exiting. It seems best suited to orchestral repertoire, where the 'mid hall' perspective allows the music to breathe. The Audiocraft's 'front row' perspective works better with more rhythmic material. So they complement each other quite nicely.
Caveat: the Audiocraft and MSL systems reflect Matsudaira's own sonic priorities. But OEM work for other companies may yield different results and in this case perhaps closer to the Accuphase 'house sound', if such still exists. So perhaps the AC-6 might sound like a more polite version of the MSL. Still with me?