Rebuild of my clone combo.

[glasman]

That is a sweet looking build! What is the black on the ends of some of the caps? Outer foil designation?

Yes, I test every cap to determine the outside foil leg and connect it to the low impedance side of the circuit.

Gary

[BobW]

Gary, that's a wonderful build! Your coax runs seem a lot smaller now too.

[Fischerman]

Yes, I test every cap to determine the outside foil leg and connect it to the low impedance side of the circuit.

I remember Randall Aiken (IIRC) mentioning this years ago on the old Ampage forum. Do you notice a difference in tone due to feedback from other nearby signals in the amp...or is it mainly for noise reasons?

And if you don't mind...what test do you perform to determine the outer foil? I thought you needed a scope and I didn't have one at the time...but I do now. Do you just do the test in Aiken's article (i.e. test leads on cap leads...grip with fingers and look at the 60Hz 'noise'...then reverse the leads and repeat...lowest 'noise' means the negative lead is connected to the outer foil)?

[HiGain]

You can download scope software for your PC. That's what I use, following Aiken's method. Works fine.

Jake

[tomrasdf]

I thought you needed a scope

I use the method Gerald Weber mentions in one of his books. Wrap foil around the middle of the cap and check the capacitance between it and either lead. The lead with the greatest capacitance between itself and the foil is the outside one. Works fine and saves buying a scope

[glasman]

Yes,

I have a scope on my bench and I simply puts the leads on the cap and grab it firmly between two fingers. I then look at the scope reading and then reverse. I typically see about a 2:1 ratio in the two measurements.

I set the scope on its highest sensitivity and pull the 5x magnifier.


Gary

[paulster]

I have a scope on my bench and I simply puts the leads on the cap and grab it firmly between two fingers. I then look at the scope reading and then reverse. I typically see about a 2:1 ratio in the two measurements.

That's exactly how I do it, and I get the same sort of difference between the two directions, so it's not easy to mistake the outside foil.

I've found it works similarly with a whole range of different caps - Sozo (although they now have a line on them), Cornell-Dubilier, Mallory, LCR, etc.