UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Sony-STR3800L. Output transistors.

samjmann · 22nd Jan 2023, 8:58 pm

Finally got round to fitting the new MJE ouput transistors. The defective channel ran up first go no problem. I'd set the quiescient current pot to minimum current before switching on. I've also added the 10pf cap across the feedback resistor too.

The service manual quotes a set up current of 50mv across 0.94ohms. This equates to 53mA, this seems very high to me. I would have thought that 10-15mA would have been Ok for a small amp like this.

Thanks again to all who have replied. Christmas, long hours at work and and the flu got in the way of a quick job!!

SJM

22nd Jan 2023, 8:58 pm	#7
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 649	Re: Sony-STR3800L. Output transistors. Finally got round to fitting the new MJE ouput transistors. The defective channel ran up first go no problem. I'd set the quiescient current pot to minimum current before switching on. I've also added the 10pf cap across the feedback resistor too. The service manual quotes a set up current of 50mv across 0.94ohms. This equates to 53mA, this seems very high to me. I would have thought that 10-15mA would have been Ok for a small amp like this. Thanks again to all who have replied. Christmas, long hours at work and and the flu got in the way of a quick job!! SJM __________________ It's never been right since we've had it...