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Hi,
My Sansui 1000A arrived with 7591A output tubes. The schematic says these should be plain 7591. Is this substitution OK without any modifications? If mods are needed, what should I do? Thanks for your help!! Vince
Follow Ups:
The change from 7591 to 7591A is just fine for your amp.If you intend to use modern production 7591As (JJ or EH) be sure the grid resistors for the power tubes are 200K and haven't drifted up in value. If they have then replace them.
Many (most?) of those old oil caps will be electrically leaky, they gotta go!
I've worked on a number of the 1000As so if you need more info drop me a note off forum.
Vince
The 1000a is a KILLER receiver and and is all my all time favorite along with the SCOTT 340a and 340b as well as the sherwood S8000IV.
The original paper in oil caps in the unit need to changed along with the doubler diodes and doubler caps.You will love that receiver.
Thanks Mike for you help. Could you please tell what diode you use
when replacing the doubler diode. I ordered replacements for the doubler caps, as they were leaking, but didn't realize the diodes should also be changed. Thanks Again, Vince
I used hexfreds in mine but I have Jim mcshanes diodes also..Jim has all the filter caps and diodes you need.
No problem, You can subsitute the 7591A for a plain 7591, but I'm not sure if you can put a 7591 in an amp that uses the a's.
Thanks truep--- That took a load off my mind!! The thought that I might have to re-tube it was not pleasant. Thanks again, Vince
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