Capacitor Outside Foil Placement Dumble

[scotto]

Had a little spare time today so decided to give this a try. Good excuse to play with a recently acquired scope. Was pretty skeptical but have always had much trust and respect for Gil and what he says. Only 3 were in backwards but 2 were in the "critical" group. I ignored the tone stack caps due to time and general laziness. WOW! I would have lost a bet on this for sure. Much cleaner and just sings and sustains like never before! Actually dialed back my delay and I'm an "always on" delay guy. Don't hesitate to do this!

[scotto]

Just to follow up with another observation, amp now seems more friendly/consistent across multiple guitars. Tried 5 different humbucker guitars and the tone seems much more consistent e.g. no need to adjust tone controls on amp, just volume control on guitar. All sound better than ever before. Pickups range from very low resistance Wildwood humbucker on my CS336 (very bright) to a higher output TV Jones on a Hamer that always sounds a bit dark. They now seem much closer tonally and somehow smoother. I'm clueless as to why it would have this effect.

[erwin_ve]

Just to follow up with another observation, amp now seems more friendly/consistent across multiple guitars. Tried 5 different humbucker guitars and the tone seems much more consistent e.g. no need to adjust tone controls on amp, just volume control on guitar. All sound better than ever before. Pickups range from very low resistance Wildwood humbucker on my CS336 (very bright) to a higher output TV Jones on a Hamer that always sounds a bit dark. They now seem much closer tonally and somehow smoother. I'm clueless as to why it would have this effect.

Enjoyable isnt it?
I did this several yrs ago and do it in every build now. My theory is the outside foil to the lowest impedance side is less receptible to electromagnetic interference.

Erwin

[scotto]

It really is Erwin. Now I need to do my other amps. Not exactly sure what to do with the tone stack caps. Just measure resistance to ground?

[digi2t]

Just a quick question regarding the first cap on the right. Since it's ultimately going towards ground (via the mids pot), wouldn't it be best for the outer foil to be orientated towards the pot?

[pompeiisneaks]

Just a quick question regarding the first cap on the right. Since it's ultimately going towards ground (via the mids pot), wouldn't it be best for the outer foil to be orientated towards the pot?

My general understanding is outer foil should always go either directly to ground if there is one (not in this case, there are other components between it) and if not, to the lower impedance or gain section of the amplifier. I.e. rejecting noise going forwards, keeping it 'back'. Since some portion of the signal you're referring to can get to the next gain stage, i.e. what doesn't go to earth via the mid pot, then it needs to remain before it instead, so noise gathered by the outside foil doesn't go further down the signal chain.

I'm personally still in the camp of the idea that the noise floor this reduces is so low, that it will make a quiet amp audibly quieter, but make no discernible difference to an amp being played at about 2 out of 10 on the volume dial.

In theory the science on the outer foil placement is solid, in practice, I think only the extremely sensitive of hearing can even tell. This is my personal theory on why audiophiles can and do search after unobtanium, it's very likely their hearing is in the ranges that 99.9% of humans can't even hear, and therefore can sense sounds the common person can't. (me)

~Phil

[digi2t]

Gotcha. Thanks for the clarification.

[libtech]

Probably already covered but is there a way to tell without a scope?

[ijedouglas]

Probably already covered but is there a way to tell without a scope?

Yes. You can use a cable plugged in to an amp. Attach tip and sleeve to cap. Side attached to sleeve when quieter is outer foil.

[Charlie Wilson]

Probably already covered but is there a way to tell without a scope?

Yes. You can use a cable plugged in to an amp. Attach tip and sleeve to cap. Side attached to sleeve when quieter is outer foil.

Yes, or you can use Martin's suggestion of simply setting your mutimeter to mV(AC) and read across the cap in either direction. The lowest reading will have your negative probe on the outside foil side of the cap.
CW

[norburybrook]

Probably already covered but is there a way to tell without a scope?

Yes. You can use a cable plugged in to an amp. Attach tip and sleeve to cap. Side attached to sleeve when quieter is outer foil.

Yes, or you can use Martin's suggestion of simply setting your mutimeter to mV(AC) and read across the cap in either direction. The lowest reading will have your negative probe on the outside foil side of the cap.
CW

Charlie, I've not heard of that method before so thanks for sharing. I've found with the current generation of orange drops it's really hard to tell now using the old 'noise' way so this will be a better method.


M

[martin manning]

I've not heard of that method before

https://ampgarage.com/forum/viewtopic.p ... 75#p417375

[libtech]

Great thanks guys, surprised on the multimeter one, one would think it shouldnt make a difference