Discussion in 'Pioneer Audio' started by bc_leszcz, May 22, 2013.
SA6300 that should read ;-)
I had the same issue and I replaced it with a yellow LED and N4007 diode connected in series. It's been working fine.
Many thanks for your informative post! Can you please describe which exactly transistors did you use to replace original output transistors? Thank you!
On the schematic diagram the lamp is marked "8v 30mA". I had a 9v spare lamp, I connected it and it worked right on the spot.
I've just replaced the output transistors as well. I used BD243C and BD244C: "C" stands for 100 volts max rating. "B" would probably have been a better choice but I didn't find them.
I followed bc_leszcz suggestion and replaced R61-62-63-64 with a pair of 200 ohm trimmers: still, on left channel I have a minimum idle current of about 45 mV (before it was more than 150mA... quite an improvement).
I'm sure somebody put his hands in there already: there's a pair of 2N3906 replacing both 2SA763s in the input stage, I'm not sure it's the right choice. On right channel I found two 2SA991 instead, but there's no evidence of desoldering in the PCB and idle current is correct. Could be that Pioneer in later production years replaced 2SA763 with it, but in my database their specs seem quite different.
About the output fuses: on the diagram they are rated 3,15A while on the PCB there's a 4A marking. I used 4A slow blow but I'm not convinced... what do you think, guys?
Ok, I replaced Q4, Q5, Q6 and Q7 with BC559B. I bought about fifteen transistors and I selected two pairs matched as well as I could. Now I read 10/11 mV on TP1 and TP2: the amp seems working fine but I wonder if it's the right value, or if I should raise it to 30 mV. I can't find anything neither on the 6300 schematic nor in the 5300 service manual. Thanks in advance for your suggestions.
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