Rotel RA-980BX equivalent transistors

[WernerLouw]

Hi All,


I have a Rotel RA-980BX amp with a blown channel. I have sourced most of the transistors, but am struggling to find the other 4.


Part numbers as follow:
2SC3478
2SC4381
2SA1376
2SA1667


What would be suggested equivalents / suitable replacements?


Also, some advice, I suspect the bias pot to be bad. Based on the circuit, would you think that the bad bias pot would cause the drivers and outputs to blow? Any suggestion on modification to prevent this re-occurring?


Thanks



Regards,
Werner

 

[WernerLouw]

Any suggestions?

 

[jvhb]

Hi, I think KSC3503/KSA1381 is a good replacement for the predrivers SC3478/SA1376.

But the driver pair SC4381/SA1667 are TO220 package, BCE pinout, 25w/15mhz/35pF devices.
The classic Toshiba pair SC3298/SA1306 should work here, if you can find them. Note, that you can get these new as Inchange (ISC) brand now!

PS: When asking about replacement transistors, it's a good idea to attach (or link to) the datasheets of the originals 😉

 

[WernerLouw]

Many thanks! I will have a look at these

 

[ferret]

Hi Werner,
If you struggle there is Roland Vlok in Roodepoort who may be able to give you advice. He is quite well known around these parts. Drop me a PM if necessary.
Kevin (Pretoria)