Pioneer Series 20 Ring emitter transistor recommendations needed

[brothelthug]

Hello everybody!
I have a dead Pioneer series 20 A27 amplifier in need of output transistors (I suspect that the series 20 m25 amplifier utilizes the same) .
They are 2sa1003 and 2sc2323 ring emitter transistors (to-3 case). I haven't been able to find any info or substitutions for these parts.

Googling around I found the following Ring Emitter transistors...

sanken 2sa1494 and 2sc3858
or
"super linear" 2sa1943 and 2sc5200
or
"the ultimate audio power transistor" 2sa1216 and 2sc2922

Would any of the above be a suitable replacement?

Does anyone out there have any data on the 2sa1003 and 2sc2323 ring emitter transistors? Or any recommendations to overcome this quandry?

Thanks, Ted

[Bernhard]

Are you sure the RETs are dead ?
I have a M25, RETs are MN25 and MP25.

[brothelthug]

Hi Bernhard,
Thanks for your reply.
I took them out and measured them ... a few are shorted.
Cheers, Ted

[jacco vermeulen]

Originally posted by brothelthug
2sa1003 and 2sc2323 ring emitter transistors (to-3 case).

The data:

Vcb/Vce max=150 volts
Ic max=12 amps
Ft= 20 MHz
Hfe = 50-200. 100 typical.
Pt = 120 watts
Manufacturer= Fujitsu

If it is possible to change to a different case i'd go for the Sanken 1216/2922, you will not find TO3 multi emitter devices.

[richie00boy]

You don't have to use ring emitter types as replacements. Choose from the ones you listed that have the same case style, they are all good.

Watch out for fakes, be careful where you buy from.

It would also be worth replacing the driver transistors as failed output devices often take out or at least damage the drivers.

[brothelthug]

Thanks for your help!
I'll try some non ring emitter transistors.
Cheers, Ted