Replacement transistors

[Cro maniac]

Hi everyone,

I'm in a process of repairing a vintage Saba CI310 integrated amplifier with burned outputs. It uses 2SC1827/2SA769 as an output pair (TO220 BJT's) which seem to be obsolete. Can someone recommend a modern (obtainable) replacement for them ?

Thanks,
Dudo

 

[JonSnell Electronic]

Try here for some ideas; TIP41C pdf, TIP41C description, TIP41C datasheets, TIP41C view ::: ALLDATASHEET :::

 

[sajti]

Hi,

I would give a try to any of the MJE150xx family.

Sajti

 

[johnr66]

FJP5200/1943. Same transistor die as the more powerful package but used in a TO-220 with power derated to 80 watts for the smaller package. Cost much less as well. Gain is nearly flat in the current range your amp would use.

 

[AndrewT]

That would be ideal for a multi-parallel output stage that gives a high level of ClassA current from a optimal bias triple EF.
Try 5pairs of 80W devices into 0r1 emitter resistors.
Bias to ~190mA each for a maximum ClassA output current of ~1.9A (=14W of ClassA into 8ohms) and a maximum output power of 160W into 8ohms from a 40-0-40Vac transformer.

 

[Cro maniac]

Thank you guys 🙂

I put MJE15030/MJE15031 in as I could buy them in my neighborhood and it is singing again 🙂. With new transistors it was biased too high so I replaced one resistor in biasing circuit with multiturn trimmer which I had in my drawer and biased it to current level of the other channel.