The MJ21195/96 aren’t really a lesser version of the of the MJ21193/94. Back when Motorola made them there was a difference as one set were 200v devices and the other 250v. When Onsemi took over they’re now both 250v. The 93/94 have slightly better gain and higher currents while the 95/95 pair are the better choice for amplifiers with higher rail voltages (100v or higher). Realistically they’re so ridiculously close that in the end it really doesn’t matter. Pick one set and they’ll work. I’m surprised they haven’t EOL’d one of the sets. I still have about a hundred pair of each, but with the NPN of the 93/94 set being hard to get I’m using the 95/96 set a lot more often. But I definitely wouldn’t consider it a “lesser” set.
Depends. I likely shorted some supply to the base of that output transistor and punctured the junction. Wouldnt effect the other necessarily. Lucky it opened instead of shirting or there would have been alot of smoke!
Fisher had darlington setups of this vintage. The principal is similar here except they have single junction bi polars and emitter follower style output design for impedance matching. Maybe they just didn't trust the darlington output transistors available at the time.
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Thanks, Mark that means alot.
Well explained, You cover it well, Nice work
They sound so nice, live some old school pioneer stereo.
828 is one of my faves. My 2nd receiver was a 727. I got a soft spot for these
Well you fixed it and it's better than it was before the slip up.
Can you tell I'm on your side lol.
Knowing what i know after fixing the channel it might have failed on its own so im happy i screwed it up. May not have noticed it otherwise!
on the right conner top shelves looks like a old vantage tv cool
The MJ21195/96 aren’t really a lesser version of the of the MJ21193/94. Back when Motorola made them there was a difference as one set were 200v devices and the other 250v. When Onsemi took over they’re now both 250v. The 93/94 have slightly better gain and higher currents while the 95/95 pair are the better choice for amplifiers with higher rail voltages (100v or higher). Realistically they’re so ridiculously close that in the end it really doesn’t matter. Pick one set and they’ll work. I’m surprised they haven’t EOL’d one of the sets. I still have about a hundred pair of each, but with the NPN of the 93/94 set being hard to get I’m using the 95/96 set a lot more often. But I definitely wouldn’t consider it a “lesser” set.
Great work, this receiver is turning the corner!
I'm really surprised that it only popped one output transistor instead of both---I would think it would affect both equally?
Depends. I likely shorted some supply to the base of that output transistor and punctured the junction. Wouldnt effect the other necessarily. Lucky it opened instead of shirting or there would have been alot of smoke!
Jesus, i wish modern amps were this easy to work on lol. is this a similar principle to darlington setups then jordan?
Fisher had darlington setups of this vintage. The principal is similar here except they have single junction bi polars and emitter follower style output design for impedance matching. Maybe they just didn't trust the darlington output transistors available at the time.