Problem with volume control on mag pick ups.

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JACK G
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Posts: 18
Joined: Wed Jun 01, 2022 2:12 am

Problem with volume control on mag pick ups.

Post by JACK G »

I'm in the process of restoring another P38 - not the one in my "My Parker P36/P38 hybrid project" posts.

All was working OK with the electrics except the mag pickups volume control was crackling when turning volume up or down.

I gave it a good dose of switch clean but the crackle is still there and now the mag pickups are quiter!!!! I have just fitted one string to test it and the volume control now has no effect - just same volume if switch is in full volume or off position. Also tone control is not doing anything which I assume is due to the volume control problem.

I guess I need to change the pot or have I created some other problem? The volume pot on the piezzo seems OK so I am hoping it is just the mag p/u volume control.

Also is this a good pot to use as a replacement...............

https://www.ebay.co.uk/itm/272443950408 ... R-zZ38zcYA?

Thanks, Jack
mmmguitar
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Re: Problem with volume control on mag pick ups.

Post by mmmguitar »

@JACK G, that pot should be fine, provided the 250k value and logarithmic taper are to your preference, and your preferred knob will fit on the split shaft-end.

I hate pot gremlins. Most guitar pots are so cheaply manufactured that, if a spritz of DeoxIT or other contact cleaner doesn’t fix an internal issue, the typical recourse is to just replace the component. There’s only so much that can go wrong with a sliding contact wiper turned across a layer of carbon residue adhered to a printed phenolic wafer; and almost none of those problems are repairable, beyond rebuilding the pot from scratch.

Any time a guitar’s on my workbench with its control cavity open, I clean its pots and switches. And it’s incredibly frustrating how many times a simple mod or repair has led to having to replace a pot or switch which has suffered a simple mechanical failure resulting from a manufacturing compromise for the sake of keeping the retail price of the component as low as possible.
Summary of the Parker Guitars speculator market, 2020-2022: https://en.wikipedia.org/wiki/Greater_fool_theory
JACK G
New Member
Posts: 18
Joined: Wed Jun 01, 2022 2:12 am

Re: Problem with volume control on mag pick ups.

Post by JACK G »

Thanks @mmmguitar for your response and I will order one today.

Regards, Jack
JACK G
New Member
Posts: 18
Joined: Wed Jun 01, 2022 2:12 am

Re: Problem with volume control on mag pick ups.

Post by JACK G »

I managed to replace the volume control a couple of days ago but the problem with the very quiet pickups remained.

Today I had a really good look at the wiring and checked to see if all the connections were OK. They seemed fine.

I then checked my wiring against the P38 wiring diagram on this forum and discovered that the shield wire from the jack input lead had come adrift from the power chip - it was a clean break so was not easy to spot.

Now all is OK - a working volume control without crackling and the pickups all back to normal.

Just one little wire!
mmmguitar
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Re: Problem with volume control on mag pick ups.

Post by mmmguitar »

JACK G wrote: Fri Sep 09, 2022 1:10 pm Just one little wire!
Often the case! Congrats on knocking another one out.
Summary of the Parker Guitars speculator market, 2020-2022: https://en.wikipedia.org/wiki/Greater_fool_theory
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