- Joined
- May 14, 2014
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- 2,277
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- Southwest Kootenays BC
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- No such things as bad days, just bad moments
I dug into an old receiver again that I thought I got working well in 2017. It was doing OK before packing it up for my move in April but it fritzed as soon as I turned it on recently. Blew the main fuse and as near as I could tell, three resistors in one channel got hot, as in at least one was smoking. They have since been replaced.
Between 2017 and now, all electrolytic capacitors have been changed out.
No schematics exist for this thing so in November 2017 I followed an AK thread about a Pioneer receiver with a 2SA497 / 2SC497 pair for drivers, the same as those in my receiver of which one was bad. The thread I was following claimed KSA1220 and KSC2690 were suitable replacements so that's what I used.
All four output transistors mine had were 2CS3055's but from different makers or of different ages so I put in four fresh ones of those as well and like I said, it was good for a while.
Dealving into it again over the past couple of days, I learned that 2SC3055's may not have originally been in this thing but a good possibility they were 2SC1030's. And again, according to an AK thread about 2SC1030's, MJ21194's can replace those.
And I learned that KSA1220's and KSC2690's were not intended for audio.
Four of those MJ21194 outputs are $10 per plus, plus and I would need to order BD139/140 driver pairs. I can get them all from Mouser.ca but would this be a mismatch therefore a waste of money?
Between 2017 and now, all electrolytic capacitors have been changed out.
No schematics exist for this thing so in November 2017 I followed an AK thread about a Pioneer receiver with a 2SA497 / 2SC497 pair for drivers, the same as those in my receiver of which one was bad. The thread I was following claimed KSA1220 and KSC2690 were suitable replacements so that's what I used.
All four output transistors mine had were 2CS3055's but from different makers or of different ages so I put in four fresh ones of those as well and like I said, it was good for a while.
Dealving into it again over the past couple of days, I learned that 2SC3055's may not have originally been in this thing but a good possibility they were 2SC1030's. And again, according to an AK thread about 2SC1030's, MJ21194's can replace those.
And I learned that KSA1220's and KSC2690's were not intended for audio.
Four of those MJ21194 outputs are $10 per plus, plus and I would need to order BD139/140 driver pairs. I can get them all from Mouser.ca but would this be a mismatch therefore a waste of money?
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