Cap orientation again...

[markr14850]

and assuming that the lines on the caps (you can see them on the lower left of the cap) represent the foil end of the cap

I wouldn't make that assumption. If you're going to go to the effort to try to align the foil, you should test them all.

[telentubes]

markr14850 Yes, important point. I wasn't going to make that assumption but just wanted to use the lines for an example of orientation. I would check each cap before the refit. Maybe by some stroke of luck they all went in the right way (?) the first time (unlikely).

[KT66]

I'd flip the 6th but leave the seventh. For the sixth cap, the end going to the bass pot sees 10k paralleled with the pot setting going to ground, so zero to ~10k. For the seventh, the way it is it sees the 100k slope in series with the Zo of the CF, so about 150k. The other way it's the upper part of the pot in series with the lower part paralleled with the 10k. The pot setting could make that anywhere from ~10k to 1M. With the bass pot at noon, it's ~800k. So, I'd leave the outer foil pointing at the CF.

Thanks for pointing that out, I should have looked at it closer.

[martin manning]

I'll make those changes and look for some tonal changes. This amp already sounds great, but subtle improvements in tone or feel are always welcome. Great to learn some more tricks of the trade.
Should I replace with new caps, or is it OK to just spin the old ones around?

I don't think you'll hear a change in tone, but maybe you can lower the noise floor if you get them all in the right way around. Should be no problem reusing the ones you have. I read once somewhere that the printing was applied randomly, so it would be wise to check them all.

[paulster]

The lines on PVC caps have no bearing on the outer foil end. None whatsoever.

Excuse the bold but it seems to be an assumption on these caps that the line signifies that, and it doesn't.

I've tested loads of these and never found a hint of a correlation, so the only way to identify the outer foil is to test.

Sozo caps, by way of another example, have a line which does signify the outer foil, and all of those that I've tested have been marked accurately.

[Cliff Schecht]

Polystyrenes are also marked accurately wrt the outer foil in my experience. It's nice with these because even if they aren't marked you can physically see the outer foil.

[surfsup]

As some of you know I am going to use the big Solen Fast Cap - metallized film caps for a X10 clone build. I thought it would be appropriate to ask them if there was a side with the outer foil marked. Here is their response:

Les valeurs en haut de 39uf ont le "Outside Foil" indique avec le fil le plus long. Pour les valeurs en dessous il sont du cote du logo "S"

This says the values larger than 39uF it is indicated by a longer lead on one end. The values smaller than 39uF, the outside foil is on the side marked with the S logo. (maybe this will help someone one day)

I do have a question, since I'm using these as rail caps, the outside foil should go toward ground? Not sure if it even matters on the rail.