I need a potentiometer.

[easybass]

The volume control (potentiometer) on my 70's electric upright bass was damaged, and I need a replacement. On the pot is printed AB (in an octangular outline), TYPE W, WA4G032P205RA, 2.0 MEG. The body of the pot is 1/2" across and the connectors the wires are soldered to point straight down from the bottom of the pot. It must be this size and style so it will fit through the opening in the body of the bass.

The pickup is a Barcus Berry piezo. Between the pickup and the volume control are a resistor, brown, bands red, red, yellow, gold and a ceramic capacitor, red, printed 25U, 120OM, 1KV.

I have searched the internet and emailed a few sellers of electronic components, but have come up with nothing.

Would anyone here know where I could get this pot, or an equivalent?

Any info much appreciated.

[Enzo]

AB, and the logo it sits in are trademarks of the Allen-Bradley company that made the part. ANy brand will do if it meets the resistance and mechanical criteria for your application.

The resistance is 2Meg - 2 megohms - 2,000,000 ohms.

If Barcus Barry made the thing, contact them and ask if they still have such a part.

Can you post a photo of the bad one? I expect we may find something similar at a supplier like Mouser or Allied.

If the 1/2" dimension is important, try looking for 12mm instead. Most pots are dimensioned in metric units rather than inches, though I am sure there are exception.

[diagrammatiks]

does the pot look like this?



that's an rv6 mil spec. Mouser, alliedelec, etc will sell them. I think RA is a linear pot designation.

[easybass]

Thank you for your replies.

Yes, it looks like that's it, the RV6. But I've been to Mouser and many others and haven't found an audio 2 meg, RV6 pot. Here's a photo of the pot.

Most sites/forums I've read state that audio pots are used for volume control. But I found two people, one in this forum, who prefer linear pots for volume. There is a company offering a linear 2 meg, RV6. After hours of internet searching for, and not finding, this audio pot, its looking like I'll have to give the linear one a try.

If anyone should come across the audio version of this pot, I'd greatly appreciate it if you'd let me know.

Thanks again

[Jazz P Bass]

I would go with the linear 2M if you have a source.
Unless you use the full sweep of the pot, chances are good that you will not even see (hear) a difference.

[diagrammatiks]

if the pickup is a piezo element, there's a good chance it'll be a linear pot.

I doubt there is anyone making an off the shelf log taper rv6...if many were made in the first place.

In fact, I'm almost positive your pot should be linear since it is part of the active preamp circuit for the piezo pickup.

[Enzo]

I am inclined to agree that it is linear. The legend on your old pot as reported by you says 2M, not 2MA or 2M aud, etc.

[easybass]

Sorry so long with a follow up. I've been away from the computer.

I put in a new 2meg pot (from surplussales.com) and it looks like you're right, that the old pot must have been linear. The new pot isn't much different than the old one. The new pot begins raising the volume quicker, but increases it evenly all the way up - works fine.

Thanks for the input.