If amplifier output power is most important to you, see post #8, no need for those smiles,550 W with+ /- 65 V dc
Regards zeoN_Rider
Regards
Yes, but i have only 5 of them. Used - but working o.k. in testing circuit as constant current source.
regards
frank
For rail voltage over +/-65V DC, BC546 must be replaced with 2N5551 (reversed pins!), 2N3773 must be replaced with MJ15024 and MJE15031/MJE15030 with MJE15032/MJE15033.
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Crown DC300A used four pair 2N3773 on ±65V for 300W/4R x 2 (1.5KVA transformer).
2N3773 150W SOA at 70V, 150W at 100V (±70V rails max)
MJ15024 160W SOA at 80V, 100W at 100V
MJ21196 240W SOA at 80V, 200W at 100V
2N3773 150W SOA at 70V, 150W at 100V (±70V rails max)
MJ15024 160W SOA at 80V, 100W at 100V
MJ21196 240W SOA at 80V, 200W at 100V
post46.
surely not, not even for ClassB.
The output to VAS cap?
The missing Re on output?
The missing driver emitter load?
surely not, not even for ClassB.
The output to VAS cap?
The missing Re on output?
The missing driver emitter load?
to lose >20V between quiescent PSU voltage and maximum peak output voltage is very poor performance.
I would expect >200W into 8r0 and just under 400W into 4r0 from +-65Vdc when biased to quiescent currents.
550W into 2r0 is a reasonable short term target while the output devices are still cool. I would expect better from a 4pair output stage.
This is old simple circuit, and poor performance are expected for retro design, but work good and easy for made. This is amp for begginers as I say, for make expirience and have fun.
Regards
If you can have PSU without voltage drop with full output power, you can get 120Vpp or 42vRMS output voltage with +/-65V DC rail voltage. That will be 225W/8R or 450W/4R with 1% THD, or 300W/4R with 0,1% THD like CROWN DC300 with 1,5kW transformer. Power is not important, this amplifier give great chance for begginers to made functional amplifier.
Regards
if power is not important then why call this a 550W amplifier?
Why do you show a 4pair output stage?
Why do you show +-65Vdc as the supply?
I would suggest a beginners amplifier should start with PSU <=+-50Vdc, 1pr output stage and specified for the real power into 8r0., not this monster of 550W. That is approaching what CAR Audio can only think about - POWER is all!
Stage 2 is the option to add a second pair to improve the current capability of the amplifier.