Had both a T400 and a T800, the T800 is a superior sounding amplifier, IMO.
The T400 had a higher rail voltage and more output devices per node. The higher rail voltage resulted in less bias current and because of the more output devices less per device also.
The T800 on the other hand was a a fully Balanced amplifier, basically 2 of the sweet sounding T200 in one chassis. Lower rail voltage more bias current and more power.
I suspect that the T400 because of the high voltage pushed the transistors out of their sweet spot. A transistor has a voltage and a current where it prefers to operate and just sounds right. With a higher voltage one can only adjust the current so high before the heat sinks become too hot.
Good Listening
Peter
The T400 had a higher rail voltage and more output devices per node. The higher rail voltage resulted in less bias current and because of the more output devices less per device also.
The T800 on the other hand was a a fully Balanced amplifier, basically 2 of the sweet sounding T200 in one chassis. Lower rail voltage more bias current and more power.
I suspect that the T400 because of the high voltage pushed the transistors out of their sweet spot. A transistor has a voltage and a current where it prefers to operate and just sounds right. With a higher voltage one can only adjust the current so high before the heat sinks become too hot.
Good Listening
Peter