Re: Noisy headphone pot - how to fix?

I had noisy pots on my MixPre. The supplier could not fault it so wouldn't
take it back. I had a suspicion it was from DC getting onto the pots. It
seemed to happen when I moved it just after a peek and the limiter LED
coming on. I read that they can be noisy when they power up so traced it
back to a problem with my power supply being a little low. Having said that
it still happens now and then. I have a 302 now.

Adam



"Greg Glazier" <glazierg@xxxxxxxxx> wrote in message
news:1126459366.099661.274640@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> RC wrote:
>> Replace it. Failing that get some contact cleaner and try and get the
>> stuff down the shaft. But the best way is to replace it. You can try
>> replacing it yourself if you are good with a soldering iron. I haven't
>> worked on a 442 but on the Mix Pre the board is double sided so you cut
>> the pot out and remove the pins one at a time.
>>
>> I have had trouble getting pots though. I still have a Mix Pre waiting
>> for a pot.
>
> That still may not fix the problem. It's a little-known fact (in my
> best 'Cliff Claben' voice) that even a small DC offset on a pot will
> cause noise nearly identical to a "dirty" pot. The DC offset will
> remain if you switch out the pot, and may be an indication of something
> far more serious going on.
>
> g2
>


.

Relevant Pages

  • Re: How do you design a circuit?
    ... pot for gain and a pot for offset, and you could turn up the gain and ... watch pos and neg clip, or you could adj the offset and see one or the ...
    (sci.electronics.basics)
  • Re: Opamp offset voltage problem
    ... configure the opamp in an unity gain buffer and measure the output. ... connect the pot wiper to the inverting input. ... Calculate offset at the input as output voltage times ... There are nulling cicuits here: ...
    (sci.electronics.basics)
  • Re: Opamp offset voltage problem
    ... run a pot from the op-amp output to ... connect the pot wiper to the inverting input. ... Calculate offset at the input as output voltage times ...
    (sci.electronics.basics)
  • Re: Noisy headphone pot - how to fix?
    ... Failing that get some contact cleaner and try and get the ... > stuff down the shaft. ... > the pot out and remove the pins one at a time. ... The DC offset will ...
    (rec.arts.movies.production.sound)