Blend Pot Question

[75Destroyer]

I was asked to fix a new Bass for my sons friend. It has a broken potentiometer on an Ibanez 5 string Ibanez :: Basses :: SR535

It looks like it's similar to my EMG hardware as the bass uses a pre-amp and the pot in question is labeled something like (25k -25k) It's hard to read under the solder. In the diagram on the Ibanez site, this pot is used in place of a standard three way switch.

I was ready to order a standard 25k pot and noticed that Stew-Mac sells blend pots just for the purpose of blending between the pups rather than simply switching. They only sell 250 and 500k pots for this purpose.

Is there a difference between a standard 25k pot and the so called (blend Pot)?
I can't seem this hardware anywhere on the Ibanez site.

[thumbs]

You might want to open the old pot and see if it's been modded to a no-load type control. This is often done with blend pots to prevent leakage and take the pot out of the circuit when not in use. Look for a cut in the carbon trace or possibly some insulating material on one end of it. If you find anything, you can modify the new pot accordingly.

[David Schwab]

Originally Posted by 75Destroyer

Is there a difference between a standard 25k pot and the so called (blend Pot)?
I can't seem this hardware anywhere on the Ibanez site.

The blend pot is a dual ganged center detent pot, and the taper is in opposite directions on each one. One side is log, and the other deck is antilog.

I wouldn't get the one from Stew-Mac though. The taper runs the same way on both. Get the one from AllParts.

When you wire it up, you have to make sure the grounds and the hots go to the right side. Set the pot at the center detent, and then take a meter, and measure from the wiper (center lug) to each outside lugs. The lug with the lower resistance goes to hot. The one with the higher resistance goes to ground. This is very important, as the pot will not work properly the other way.

The other deck is reversed. The pickups attach to the wiper lug.

[75Destroyer]

Originally Posted by David Schwab

The blend pot is a dual ganged center detent pot, and the taper is in opposite directions on each one. One side is log, and the other deck is antilog.

I wouldn't get the one from Stew-Mac though. The taper runs the same way on both. Get the one from AllParts.

I guess I'll order both pots, the allparts blend pot and a standard 25k pot. I'd feel better with the duel gang (as you put it) since that's what it's designed to do. I'll still have to dissect the old one as Thumbs suggested, it's not a duel gang and looks like any other but I suppose it could be some kind of proprietary part. I've never seen 25k - 25k listed on anything I've ever replaced.

With little knowledge of potentiometers, I assumed it was the same kind of of pot, just wired different. I guess it does something completely different than either volume or tone so it would have to be different.

Thanks for the help both of you, I'm off to find some more pot schematics so I can have a better understanding of whats going on here.

[David Schwab]

Originally Posted by 75Destroyer

I guess I'll order both pots, the allparts blend pot and a standard 25k pot.

You can't use a regular 25K pot to do blending.

25K Blend/Balance Pot | Allparts.com

Are you sure it's using 25K blend pots? Are they active pickups?

[thumbs]

Destroyer, I just reread your original post. If the bass has no selector switch, I think I'd go with David on this one. Sounds like a pan pot to me; a little different than the "blend" pot we strat players use to get more pickup combinations out of the 5-way switch. Sorry if I gave you misleading info.

thumbs

[bsmith]

You can also try Acme Guitar works as they also sell CTS blend pots.