Post by wdln on Dec 19, 2020 17:02:55 GMT
Hello... I'm working on the amp for an R-80. The amp is an R-2179A. Each driver board uses two Darlington power transistors, a Motorola MJE6044 (NPN) and a MJE6041 (PNP) in TO220 cases. Both transistors have failed on one of the boards; I have a transistor tester that shows both of them as bad and it immediately blows one of the fuses when the amp is unmuted. There are a few NOS MJE6041's on ebay right now, but I can't find a 6044. I was doing some cross referencing and found the 2n6045g, which has similar specs, although it's the slightly different TO220AB case (should still mount to the heat sink though).
Here are the specs for the Motorola MJE6044 and suggested cross-references. The 2n6045g at the top of the list seems closest, just with higher Vcb and Vce limits but otherwise identical.
alltransistors.com/crsearch.php?mat=Si&struct=NPN&pc=75&ucb=80&uce=80&ueb=5&ic=8&tj=150&ft=4&cc=200&hfe=1000&caps=TO220
Does that seem like a plausible substitute? There are a handful of NOS 6044's out there but I can get these for a fraction of the cost. And looking at equivalents for the 6041, the 2n6042g would also be a much cheaper substitute.
alltransistors.com/crsearch.php?mat=Si&struct=PNP&pc=75&ucb=80&uce=80&ueb=5&ic=8&tj=150&ft=4&cc=300&hfe=1000&caps=TO220
If I went with anything in a TO-220AB case, I would need to insulate the screw going through the heat sink so it does not ground out the transistor; the 6044/6041's TO220 case has the mounting hole entirely insulated.
Thoughts from The Collective?
Here are the specs for the Motorola MJE6044 and suggested cross-references. The 2n6045g at the top of the list seems closest, just with higher Vcb and Vce limits but otherwise identical.
alltransistors.com/crsearch.php?mat=Si&struct=NPN&pc=75&ucb=80&uce=80&ueb=5&ic=8&tj=150&ft=4&cc=200&hfe=1000&caps=TO220
Does that seem like a plausible substitute? There are a handful of NOS 6044's out there but I can get these for a fraction of the cost. And looking at equivalents for the 6041, the 2n6042g would also be a much cheaper substitute.
alltransistors.com/crsearch.php?mat=Si&struct=PNP&pc=75&ucb=80&uce=80&ueb=5&ic=8&tj=150&ft=4&cc=300&hfe=1000&caps=TO220
If I went with anything in a TO-220AB case, I would need to insulate the screw going through the heat sink so it does not ground out the transistor; the 6044/6041's TO220 case has the mounting hole entirely insulated.
Thoughts from The Collective?