Re: List of Bad Cap Manufacturers

Nope... I thinks it was a "Sino" brand (China).
Probably Lelon, though I guess that's technically Taiwanese. (R.O.C.)

BION (Bleeve it er Not), there are folks out there offering update kits for the fancier Behrenjer (sic) products, where they supply you with better OpAmps (to replace "economy" TL074s, for example) and higher-Q, Lo-ESR electrolytics.
They claim (& I don't doubt it) the part kits- once installed- improve the overall 'sound' of the product *immensely*. See, for example:
http:...

Re: Cap self-recharging

Thanx, kc8 ! didn't figger Wiki had an actual page on the phenomena.

Re: List of Bad Cap Manufacturers

I know Be'ren-jer (sic) products use crap Chinese caps in their power supplies.
I forget the cap maker, but there was an 'O' or 2 in the name.
Replace 'em all with some good 'uns like Panasonic or United Chemi-com (UCC) & those beast will actually work for a good while!... until some other cheep part bites the wazoo.

Re: Cap self-recharging

Steve, et al:
On the webpage you linked us to, Tony Stewart posted:
"On large electrolytic caps, like "main-frame" computer grade 100,000uF and TV HV 10uF 25KV doubler Caps, power supplies there is a phenomena like in batteries, known as memory. After you short it out the voltage creeps back. That's all you need to know. Short it long enough to discharge the memory effect."

Hmmm... All I need to know, huh? ("But wwhhyyyyy??", markie cried.)
P.S: I've discharged some old caps in gee-tar' amps for...

Re: Cap self-recharging

Steve, You might be the closest so far.
It certainly doesn't charge from the voltmeter, Per, as they "drain" the source- to varying degrees- due to the impedance of their input. (VTVMs or "vacuum tube voltmeters", were the highest input-Z meters out there for a LONG time and presented a load no more than a couple megohms, if that.)
Nope, stj, i think any & all EMF fields "permeating" the cap would both charge & discharge the cap, as it is all essentially A.C., resulting in a cancellation of any added DC charge....

Hi folks,
Ya know, for years I've always wanted to know just how an electrolytic capacitor, especially a Hi-V filter type, can seem to "recharge" itself after a full drain via a temporary short across it's leads...
In other words, what kind of chemical action or re-action- or other electrical phenomena- accounts for, say, a 22uF/ 500 volt filter cap which is *removed* from any circuitry (isolated) developing up to several measurable volts across it's plates (leads) if it's been in service for some time?
An E.E. assistant college professor said it was beyond the...

Re: Peavey KB100 popping and thumping with humidity

Carefully resolder all low-level audio stages, clean the P.C. board in the preamp area, dry it COMPLETELY and then try spraying some clear non-conductive sealent over both sides of the board.
The goal is to make any connections which are in close proximity with each other [in the preamp or output driver I.C. area] from having moisture [beads] conducting spurious D.C. currents around, like between pin 3 (+ In) & 4 (-Vcc) on a dual (or single) op amp I.C. That should help.

Re: New Members - please post your introductions here

Hi All, I am from apple-snapper country (NH,USA) & have made a living servicing 'tronics' since college. Good to see a Site with great technical information resources. Hope to add shematics, diagrams & repair tips over the next few months... on music industry products from gee-tar' amps to tape masheens.
Found 'badcaps' while desperately lQQkin 4 a jbl "schem". Got it! Many thanx. -M