I need to replace a couple of pots in an audio amplifier (crackle badly in some places). They are the kind that have discreet positions
- I mean as you rotate the spindle there is a distinct movement to the next position - rather than a continuous sweep. Is the correct term "ident pot" or "indent pot"? maybe. Does anyone know where I can purchase some good quality ones?
I dont think its the potentiometer that clicks per each move? could be a mechanicle piece attached to the spindle of the pot?
Have you tried WD40?
Or even just a shaft-encoder which feeds a digital attenuator. The detent might be built into that 'cos it's only a couple of slotted optos to give a quadrature signal. Like the wheel on a mouse.
Thats an oil lubricant not a cleaner for electronic parts ie you should of said "Servisol"
indents. You'll find them very hard to find unless you salvage some from another amp or go to the mfr. The good news is standard pots without indents should work fine.
If you must have the indents but wont pay the price, you could always transfer tracks from a new pot to the old pot case.
What excatly is the problem, as many pot faults are easily repaired.
NT
What excatly is the problem, as many pot faults are easily repaired.
NT
Erm! the audio crackles as he's turning the control.
Fair enough, but it works extremely well. You should have said 'have' instead of 'of' ;)
If you must have the indents but wont pay the price, you could always transfer tracks from a new pot to the old pot case.
What excatly is the problem, as many pot faults are easily repaired.
NT
There are no indent pots as this would be uneconomical for manufactures to implement them into their systems. A variable pot like this usually uses a ball bearing in a plastic case ie the ballbearing jumps from one increment to the next per each smmall turn.
Yes I have fixed such an item in the past.
Isn't the term 'detent'?
There *were* pots with indents, typically stereo balance pots - usually a single click at the centre position. On occasion I've had these custom made by Morganite Resistors (part of the Morgan Crucible Company), although I think that firm's long gone now. There was one I remember - it was a twin semi-log/reverse semi-log
50kohm with, ISTR, a two-pole on-off switch. It took about a week to produce :-)You could try Vishay:-
I really can't see any saving grace in WD-40 (even though I subscribe to uk.rec.sheds).
It's neither a penetrating oil (PlusGas is much better), nor a lubricant (even 3-in-1 is much better).
It's really only a water-dispersant (hence the 'WD'!).
To clean potentiometer tracks you could try switch cleaner, which is basically a solvent and a mild lubricant. If that doesn't work, I'm afraid it's time for a new pot...
Well I'm still optomistic because I've replaced a couple of pots in the past on Sony,Panasonic and Hitachi audio controls and never came across any detent pots,they where just normal pots,however behind the actual dial lay a circular tin sping its hard to describe but it looked like a merry go round the metal was shaped up and down on the circular washer which was the size of the plastic dial a ball bearing was encased in the dial itself with a spring behind it for forcement of the ball bearing onto the circular spring.
In article , dave scribeth thus
Have a look for "ALPS" they do most all of these in domestic equipment CPC and RS components would be a good start..
As might be a company called Alice who make mixing desks and do spares like that and a company called studiospares..
Or try the makers of the amp or a can of switch cleaner spray..
Here's a better explanation of it.
Just try it Frank, you'll be amazed. Obviously, if the track is worn down through to the substrate it 'aint gonna help a lot.
They seem to be very difficult to find as spare parts - although plenty use them new. I've even got a couple of dimmers like that.
Have you tried searching for it as a maker's spare part? It's also sometimes possible to fit the track from a different pot to them - the 'indents' are usually just a mechanical action.
A good site to check is the Alps one.
Yes - and the positions will be discrete, rather than discreet :~)
Right sentiment - wrong material. Do not try WD40. Use a good quality switch cleaner / lubricant which is made for the job. Maplin will sell you a can. It's pretty rare not to be able to recover even very 'scratchy' pots, if you use the right stuff and technique.
Arfa
I don't have a degree in chemistry, but WD40 works fine, try it Arfa. I'd imagine that most fluids (except for maybe water) would work although I haven't tried scotch or Banks's (which might be terrific).
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