Hey what's going on? so when I play music through the amp the left channel is distorted the right channel is clear. when I moved the amp, both channels went completely distorted and I had to unplug it, loud buzzing through the speakers and buzzing around the bad darlington area. I pulled the Darlington transistors and tested them, I will include pictures. the one marked RR for right right, seems to be testing faulty. should I just start by replacing the four or one darlington's? if so what would be good replacement for that? Thank you.
SAE MARK XXXIB distorted channel, then loud buzzing.
- Thread starter robc23
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- 31b amp darlington help mark repair sae transistor xxxib
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The originals were 2N6284 and 2N6287, the 2N6284 is still available if not Back Ordered, the 2N6287 went obsolete a couple of years ago and tough to find. Hamrules listed the current transistors that will work. I just checked Mouser and all are in stock but only two of the MJ11015G. If you have shorted output transistors you'll want to replace the bias IC at the same time, CA3046 or CA3086. Cool little amp, I rebuild lots of them. Super simple also.
DON'T MIX the different pairs.
Craig
DON'T MIX the different pairs.
Craig
That listing isn’t necessarily 100% accurate as is but is great for assembling info
Ok I will go with the 15 and 16. I'll replace the ic as well thank you
CA3086 / IC / DIP / 2 PIECES (qzty) | eBay
We have that item. All parts are warrantied from date of receipt.
www.ebay.com
The 46 and 86 are essentially the same, the 46 has a matched differential pair. Doesn't really matter the way it's used in the amplifier. As long as it's not coming from China you should be OK, probably not a lot of call for this item so no fakes. You can also look for LMxxxx series. Jameco has 100s of both in stock.
Craig
Craig
I'm also going to install a volume control. I've done this in a few dynacos of mine. https://www.ebay.com/itm/1335696190...94C1ayOSeG&var=&widget_ver=artemis&media=COPY
Should work, the ones in the P500’s I did were 50K.
How can I be positive which is the npn/pnp location? Wouldn't want to mess up the installation. Somebody did write on the board but I'd like to be 100 percent. 2nd pic pulled from web. Looks legit.
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The easiest way is to look at the big RED(+) and GRAY(-) power supply wires, the 2N6284/MJ11016/NPN go on the RED side, the 2N6287/MJ11015/PNP go on the GRAY side. OR in SAE speak, the lower number SAE103 will be the NPN transistor and the SAE204 will be the PNP. Clear as mud now.