Pilot 240 Integrated Amp questions

[Ziradog]

I finally procured, tested, painted, and installed the replacement output transformer for this unit, and I am starting to re-cap it. First oddball thing that came up was in the power supply, specifically C1A & C1B (2 halves of a can capacitor). On the attached schematic (from a SAMS I bought), the A half is 80 mfd and the B half is 40 mfd (see schematic section attached). On my unit, and on the doner unit my OPT came from, these are reversed. I am guessing that this is a schematic error but I would like a sanity check. Does it make sense to have the 40 mfd "first in line" so to speak, then the 80 mfd next?

Next question. My amp is full of "Imp" capacitors that I plan to replace. The donor unit has a mix of "Imp" and some other brand. Sometimes there will be an Imp in one channel and the red/white brand in the other. Same values & voltage ratings in both amp. Any idea why that might be (other than pricing at the time)?

Thanks.

 

[FlaCharlie]

I finally procured, tested, painted, and installed the replacement output transformer for this unit, and I am starting to re-cap it. First oddball thing that came up was in the power supply, specifically C1A & C1B (2 halves of a can capacitor). On the attached schematic (from a SAMS I bought), the A half is 80 mfd and the B half is 40 mfd (see schematic section attached). On my unit, and on the doner unit my OPT came from, these are reversed. I am guessing that this is a schematic error but I would like a sanity check. Does it make sense to have the 40 mfd "first in line" so to speak, then the 80 mfd next?

Next question. My amp is full of "Imp" capacitors that I plan to replace. The donor unit has a mix of "Imp" and some other brand. Sometimes there will be an Imp in one channel and the red/white brand in the other. Same values & voltage ratings in both amp. Any idea why that might be (other than pricing at the time)?

Thanks.

You're correct, the Sams is in error. The first cap after a 5AR4 rectifier should be replaced with a 47uf if you're replacing the can sections with individual caps. If you're using a replacement can, don't go over 50uf for the first section. For the second section you could go a bit higher, say 100uf.

You're probably also correct about the reason for the mix of other caps.

 

[gadget73]

40uf straight off the rectifier makes more sense. Datasheet limit on that I want to say is 60uf, though thats also if all other conditions are at max. You *might* get away with 80, but it would be a lot harder on the rectifier tube.