hello
i have problem with transistors in my peavey 112 express. one of them (motorola 70483100 W9252) gone bad and i'm having problem finding the same one or the one to replace it. the transistor is paired with A8520 BDY57. people who tried to repair it for me had problem finding the first one which would be working. tried to replace with similar but it got bad the moment i started to play. do you have a solution fot it, is there a place where i can buy transistor motorola 70483100 W9252 paired with the other one (A8520 BDY57) or thh first one alone or is there any other pair of transistors which can work with this amplifier.
looking forward to hearing from you
best tomek

70483100 is a Peavey part number, and you can order the part from any Peavey dealer. The real world equivalent part is an MJ15015, an NPN. The 70473100 would be a MJ15016 type, the PNP compliment.

The W9252 is not a part number, it is a date code, your transistor was made in the 52nd week of 1992.

The BDY57 does not sound like an original part. There are two power transistors, the 7048100 and the 70473100.

If those are burnt out, then please check the driver trnasistors - the 5331 and 5332 transistors. They are located next to the corners of the heat sink. Also make sure the two 5 watt 0.33 ohm resistors are good, and there is a 100 ohm resistor from bas to ground of each power transistor, please check that it is good.

5331 and 5332 are also Peavey part numbers, the equivalent real world parts would be MJE243 and MJE253.

If you do not already have it, get the schematic from customer service at Peavey.

thanks for quick response.
so can you tell me what pair of transistors i should put in to my amplifier in order to get it to work? (70483100 and?). from what i know everything else is checked and fine. but i will double check on the things that you are suggesting.
thanks again and forgive my ignorance but i have no knowledge about those things
tomek

I already did. There are only two output transistors, one of each. In your case 70483100 and 70473100. Those are the two transistprs that SHOULD be in the amp.

If you cannot get the Peavey parts, then replace the 70483100 with a MJ15015, and replace the 70473100 with a MJ15016

thanks a lot.