transistor sugestions


2002-04-28 4:42 am
I'm looking to build a quad amped system with a active crossover and i need six 60 watt rms class-a bi-polar amps and two 250 watt rms class-ab bi-polar amps.

My question is this i'm thinking that rail supplys will be 40-75 volts +/- on the rails with matched npn/pnp pairs on the outputs with a 8 ohm load. So can anyone suggest the best output stage transistors (not mosfets) to use (preferably in a to-3 package ) and that will let me use 2 or 4 devices per an output stage for the 60 watters. The 250 watt ab can use whatever.

Also what would be the ideal voltage for the 60 watt amps, if it makes a differance.


2001-02-04 4:23 am
"Best I know are 2sc2922 (npn) and 2sa1216 (pnp) "
These are plastic MT200 package, not metal TO3 type. What is the difference? Glad you asked. The A1216/C2922 are about $6 each, the MJ21193/94 about $2 each. The A1216/C2922 when derated for a normal operating junction temperature (100*C) and secondary breakdown at 100V can handle 60W, the MJ21193/94 can handle 120W. So for the same safe area capability the A1216/C2922 cost six times as much as the MJ21193/94 on a dollar per watt basis. That is for the 250W amp. For the 60W amp the safe area improves on the A1216/C2922 so that it only costs 5.625 times as much on a watt per dollar basis.