Concept amp help please

[joesch1999]

I have a concept amp I am working on problems in the p channel has bi polars I believe a1694 and compliment c4467 driver is bd14og I think I have tried looking them up with 2sa and 2sc keep getting a dead end what could I use instead as well as what driver any help would be great.

[Perry Babin]

Which of those transistors tested as defective?

[joesch1999]

a 1694 but i am just gonna replace all of them

[jordan_ciaramit]

Mouser has them. Search 2stc & 2sta.....MCM appears to have them too. Pacific semi has them.

[Perry Babin]

I typically use the FJA4213 and FJA4313 as subs for this type of output transistor. These replace virtually all BJT outputs in this case style. The BD139 and BD140 are readily available from most distributors.

[joesch1999]

Having some trouble with this amp took out p channel fets amp was going in and out of protection that made it stay on then the drivers b631 b630 got hot should I replace them and if so what r good replacements for those Korean drivers

[Perry Babin]

If you're referring to the output transistors as FET, they are not. They are NPN and PNP bipolar junction transistors.

Why did you remove the output transistors? I'm assuming that you're referring to the new transistors.

[joesch1999]

I removed the outputs and I know they r bipolar to find out why amp was in and out of protection after removed amp powered up but drivers got really hot I was thinking maybe I bought the wrong replacement driver to replace the b631

[Perry Babin]

The BD139 and 140 are relatively low voltage devices. If you used them in an application where the supply voltage exceeds their rated voltage, that could cause them to overheat.

[joesch1999]

Ok I take it b631 replacement is bd139