Citation 22 output transistors needed

[rickl]

I'm trying to bring back a dead 22.

I've narrowed down the problem to the outputs and drivers.



I need:
Q439 2SC3298A, NPN
Q437 2SA1306A, PNP
Q441,Q443 2sc3907, NPN
Q449,Q451 2SA1516, PNP

a search suggested 2SA1516 / 2SC3907 can be replaced with 2SA1962 / 2SC5242 for a big yamaha.

Is this correct?

What about the 2sc3298a/2sa1306a pair?
I did find this in the transistor replacement thread suggest 2SA1837 and 2SC4793

Do these suggested replacements look correct? These are available at digikey or mouser.

I did check the pre-drivers and they appear to be good.

Thanks!

 

[ivandezande]

For the driver pair MJE15032/33 should work, they always seem to.
For outputs, I'd use NJW3281/NJW1302. All are On Semi and in stock, I've used all of them many a time with great results.

 

[rickl]

Thanks Isaac. I should have the mje15032/33 in my parts bin too.

Since everyone likes nudies

 

[rickl]

Thanks again Isaac. I replaced the drivers with MJE15032/33 and outputs with NJW3281/NJW1302 and got both channels working. Both channels look like:



I need to adjust adjust bias, check DC offset but nice to see both channels working.

 

[ivandezande]

Thanks again Ivan. I replaced the drivers with MJE15032/33 and outputs with NJW3281/NJW1302 and got both channels working. Both channels look like:

View attachment 1500106

I need to adjust adjust bias, check DC offset but nice to see both channels working.

Lookin good!

 

[rickl]

Just a quick follow up.

This amp sounds great and a lot of power.

Realized the display didn't work.

Fixed the power supply for the display board. One resistor, just had to find which one.



I think I'm done with the amp. A few caps, a few resistors and a few transistors. And correct sized fuses.