I have a SAE a202 amplifier that has a output transistor 2SD845 that is shorted collector to emitter. Nothing else looks bad , the transistors on amp pcb check good. It has 2SC2238(Y) and 2SA1112 for drivers. Outputs are 2SD845 and 2SB775. I planned on replacing the bad transistor and I normally replace all outputs when I can. So what would be a good replacement for this that is avail. I was thinking 2SA1302 and 2SC3281? for the outputs. Would that work here? I can replace the drivers if i need to work with new outputs any suggestions?
Sae A202 amplifier - 2sd845 replacement
- Thread starter Trebolo
- Start date
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The SAE 2600 I just completed used that Toshiba pair for drivers and unfortunately they were pretty battered physically and I broke some of the leads while cleaning them. Now what? I first thought of the big MT200 xsistors but they were too wide to fit the 2600's heatsink bracket. I ended up re-drilling the PCB and bracket and used some ON MJW or MJL, not sure of the numbers until I get to the shop tomorrow. So if the MT200s are too wide for what you need the ON Semis will work fine with some reworking of the mechanics. Are the collector tabs used on the drivers?
I probably could have found some NOS Toshibas but the goal for this rebuild was to use currently made parts so the next repair if needed would be an easy task.
I probably could have found some NOS Toshibas but the goal for this rebuild was to use currently made parts so the next repair if needed would be an easy task.
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The collector tabs are not used on this amp. And I will have to drill a mounting hole on the sink for the outputs, but it will fit no problem.
I'm pretty sure I used the MJW pair. Use MJE150xx for the drivers. Have you seen Motorola AN1308 by Andrew Hefley? Pretty good reading about amp design using then/now current Motorola xsistors. You can see SAE and GAS in both of the AN1308 designs. Andy was the last owner of Great American Sound if you didn't know.
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It sure will fit.....Which one is better to use here. I had not seen those and will remember them for future reference , thank you
I am going to use the 2SA1215 /2SC2921 from digikey. Thanks . The OnSemi fanboy in me wants to modify the heat sinks and use the MJL3281/1302 since I have 50 of each. But the realist in me knows that would be unnecessary here. I will get this working and post pics of the restored unit. There are no schematics for these, so I will be posting detailed pictures
SVI2004A
Synchro Bias
Damn well worth it in my books.. I have gear in the commercial field.... SanKen is a saviour stands up to the customers thrashing’s at parties... I quickly wore thin of Toshibas efforts
At first I thought you meant that the Toshibas were damn well worth it but then your last sentence says maybe not. So what is damn well worth it, SanKens? I don't disagree but they were not an option for the 2600. I would have had to grind the sides of the transistors for them to fit on the heatsink bracket.
For sure grinding the transistors would be a bad idea He meant the Sankens are the better option for sure over the Toshibas. I just bought a gaggle of 2SA1215 /2SC2921 I like to have a few sets and this way I can get as close to a match as possible. I will be making a new test jig tonight for the MT200's as they wont fit my Curve tracer jig. But will be fun to make a new one