jwrosenthal
Super Member
Hey guys, popping over from the tube audio forum. I posted a query about refreshing my MR71's over there but got no response so figured I would ask here.
I have 2 MR71's, that have been sitting on my shelf for almost 1/2 a decade and lord knows how long before that. I brought them up on a variac this weekend not know what to expect and after a few issues that got sorted out quickly, they both work perfectly, tune perfectly, lock stations perfectly, and sound excellent....and I want to keep it that way.
I would like to refresh the power supply just to make sure they stay reliable, perhaps some of the audio section caps 1-1 (if there are particular caps that would benefit from a swap- please let me know) but I have no desire to modify the circuitry in any way (and that is above my expertise- I can solder and swap parts with the best of them, thats about it).
Can anyone point me to a tutorial that would tell me exactly how to replace the selenium rectifier, what kind of caps I should replace the paper orange cardboard caps with, and the procedure for bypassing the can cap and wiring with new caps -preferably underneath- so I don't change the esthetics from above. Pictures with arrows and things circled make it rudimentary enough for me to follow, schematics make my brain hurt. I don't have the equipment to do any kind of testing other than a multi-meter, just want to make sure they don't go poof one evening while doing dishes.
Appreciate any advise,
James
I have 2 MR71's, that have been sitting on my shelf for almost 1/2 a decade and lord knows how long before that. I brought them up on a variac this weekend not know what to expect and after a few issues that got sorted out quickly, they both work perfectly, tune perfectly, lock stations perfectly, and sound excellent....and I want to keep it that way.
I would like to refresh the power supply just to make sure they stay reliable, perhaps some of the audio section caps 1-1 (if there are particular caps that would benefit from a swap- please let me know) but I have no desire to modify the circuitry in any way (and that is above my expertise- I can solder and swap parts with the best of them, thats about it).
Can anyone point me to a tutorial that would tell me exactly how to replace the selenium rectifier, what kind of caps I should replace the paper orange cardboard caps with, and the procedure for bypassing the can cap and wiring with new caps -preferably underneath- so I don't change the esthetics from above. Pictures with arrows and things circled make it rudimentary enough for me to follow, schematics make my brain hurt. I don't have the equipment to do any kind of testing other than a multi-meter, just want to make sure they don't go poof one evening while doing dishes.
Appreciate any advise,
James