Simontju wrote:
"Actually very many amplifier manufacturers use balanced output configuration. Probably all class D amplifiers use it, for example."I'm sure you know more about it than me, but nothing you say appears to me to contradict my statement. I don't know about so-called Class D amps, but among conventional power amps, as far as I know more products don't use balanced output stages than do (even if they might have balanced drive and/or gain stages). Hence my use of the word "minority", which doesn't necessarily mean very few. Obviously, some companies do make a point of advertising their fully-balanced configuration (BAT, Krell, Atma-Sphere, etc.). Others (like Conrad-Johnson and Lamm for example), although they may not advertise it as such, eschew balanced circuits as a matter of design principle because they feel balanced operation detracts from realistic sound by way of cancelled even-order harmonics more than it contributes in the form of reduced total distortion and noise (this last being more of a factor at line-level anyhow, as opposed to speaker-level power output). Most of the rest presumably don't use it because of the extra cost in having doubled circuits, with power output stages generally being the most expensive (Class D amps, whose output stages might be in the form of IC's, could be exceptions).