"Eeyore" wrote in
message
Arny Krueger wrote:


I'd personally like to see someone claim that power
transistors get more linear when run at very high
currents and that there is no such thing as beta
fall-off at high currents.

Oh there is, but since a classic Class A output has such
high standing dissipation you use more devices in
parallel and you're actually working them at lower
currents than in A/B.

I think I saw the effects of beta fall-off in my testing. I was working
with 8 devices up and 8 devices down. VCC was about 80 volts. The devices
were complements from the MJE 1502x series.

Admittedly, one go add enough devices so that beta fall-off wouldn't be an
issue.