Someone messed with the FEB boards in this amp..
The transistors on the boards are MPSA92 anf MPSA18 those are the orginal part numbers..
Someone switch the MPSA18 with C2371 on 2 of the boards ..
Looking at datasheets the MPSA18 is an NPN and the C2371 is a PNP maybe im wrong..
Anyone know if there is a good sub for the MPSA18 for testing only?
The transistors on the boards are MPSA92 anf MPSA18 those are the orginal part numbers..
Someone switch the MPSA18 with C2371 on 2 of the boards ..
Looking at datasheets the MPSA18 is an NPN and the C2371 is a PNP maybe im wrong..
Anyone know if there is a good sub for the MPSA18 for testing only?
Just buy the correct FEB boards from Jaime at JandRelectonix on ebay, saves you tons of headaches back engineering the issues. There were two distinct different boards. One used MPSA18's and the other used a dual transistor by Sanyo for the diff input pairs. Jaime should be able to fix you up with issue free new ones for reasonable though....just my thoughts on the matter though...😉
My info says only this for the board type:
PA_D13.SCH
My info says only this for the board type:
PA_D13.SCH
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I'm going to buy the replacement boards if needed only wondering if there is a good sub for the mpsa18's since every other thing on the board has been replaced with the correct parts just not the transistors. ..
I got the amp from an electronics repair shop and talked to them about it
I got the amp from an electronics repair shop and talked to them about it
Ok father digging into this amp i noticed alot wrong with it..
The switches are bad even after cleaning them..
All 4 of the FEB Boards have been messed with .
All of the outputs are mis- matched
So this amp is gonna be around $100.00 just in parts to fix correctly..
The switches are bad even after cleaning them..
All 4 of the FEB Boards have been messed with .
All of the outputs are mis- matched
So this amp is gonna be around $100.00 just in parts to fix correctly..
You have a rebuild/restoration project on your hands I would say. Also add in brand new emitter resistors, they rarely hold up, and to be sure they are all perfect just replace them all since most meters can't register properly at that low of a range reading... Jaime has all of the parts... A set of switches aren't that bad, and along with FEB boards, your still not too bad off. TIP107 & 102's are cheap enough also. Ask Jaime to quote you on the whole parts list, not onesy twosy ebay way. Hope this helps some...😉
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