Replacement for Ibanez volume pot marked 1B100?

[glebert]

Working on an Ibanez Soundwave 65 (aka SW65) bass amp for my kid. No schematics available that I can find. Traced problem to the volume pot which measures complete open to all terminals. Pot is marked "1B100 (ohm symbol)". There are some parts lists online which call out a part number of "VRRE1ECPK00A". Looking online doesn't show me what that is, other than it exists, but not available from any US supplier I see. Other pots are more conventionally marked, so I don't know if this one is a custom Ibanez thing and if it can be replaced with something more readily available. I have tried calling Hoshino USA but haven't gotten to speak to an actual person yet.

Anyone know about this part?

Thanks,
Greg

[glebert]

Did get a hold of Ibanez support but they couldn't tell me anything about the part and were going to do some digging. In the meantime I looked at the circuit and didn't see anything special about it so put in a 100k linear pot. It seems to work fine. Decent sounding little amp. While I was doing that Ibanez did get back to me and said they did have the part in stock in case anyone else is looking for one and wanted the original part. The Ibanez part number is actually 32S01749.

[Enzo]

Two steps:

1. find out what it is.

2. find a replacement.

So do you have some pots in your shop? I would solder some wires to a 100k pot and tack it into the circuit. Does it work? If so, great. If not, we could try it with a couple other values like 1 meg or 1k. Doesn't matter if it fits, we just want to verify something that works.

Then assuming a 100k - or whatever value - works, THEN we set about finding one from whatever resource that fits the amp.

[olddawg]

I would guess it’s a 100k B taper. As Enzo says. Flywire something in. It won’t hurt anything. I doubt if it’s a linear taper for a volume pot. Also look at other Ibanez amps with similar architecture.

[g1]

It's marked as 100 ohm isn't it?

[The Dude]

I read that as single (1)/linear taper (B)/100 ohm. Could certainly be wrong. If in doubt, have you tried taking apart the pot and putting your probes directly on the track? Often it's just the rivet connections that are bad. If the track is broken somewhere in the middle, measure each side of the break and add them together.

[g1]

Here's a pic that came up from that part number.

[glebert]

put in a 100k linear pot. It seems to work fine.

Perhaps I buried the update.

No idea why this part had such an unconventional marking. I was thinking it was some nonstandard pinout or something.

[The Dude]

I saw the update. If it works, it works. No problem. I'm just not sure where the "K" came from. I saw it as 100 ohms- not K ohms. It's likely just a simple voltage divider circuit, so just about anything might work.

Edit: It's not "common" marking, but I've seen it before. The B100 ohm is common (taper followed by value). The first number is used by some manufacturers to differentiate whether it's a singe or dual pot.

[J M Fahey]

Just curious: so whatīs the actual value?

Worlds apart.

[olddawg]

Do what Dude says. Take it apart. You should be able to measure the rest of the element. Measuring to the middle from each end it will give you an idea of the taper too.

[glebert]

Took apart the old pot, which was cracked off above the pins, probed to the ends of the resistive trace and it read about 100 ohms. No idea how a 100k could be working with a reasonable sensitivity, and if the amp wasn't such a pain to get back together I would take it apart just to see if it actually was 100k, but I'm pretty sure it is.

[olddawg]

Took apart the old pot, which was cracked off above the pins, probed to the ends of the resistive trace and it read about 100 ohms. No idea how a 100k could be working with a reasonable sensitivity, and if the amp wasn't such a pain to get back together I would take it apart just to see if it actually was 100k, but I'm pretty sure it is.

Then my best guess is it’s a 100 ohm B taper just like it says. Measure from the middle of the element to each end. Should be about 50 ohms each way.

[Enzo]

When I suggested 100k, it was pretty arbitrary, the idea being sub SOMETHING in there and see if it works. If it is 100 ohms, fine, though that seems a very odd value for a volume control.

[J M Fahey]

I think I can reasonably confirm itīs indeed 100k , just marked in a unique "Ibanez way".

Weird, so far could NOT find the schematic, which normally is the first Tech data available for anything, while I found various instances of its parts list, which generally is not available, unless itīs a detailed service manual

Said parts list does not fully clear it about mystery volume pot but we can compare its description to other pots (treble, bass, etc.), although all pots are called "volume pot".

* VR101 32S00265 VRRE1ECPB10A VOLUME POT B10K
* VR103,105 32S00522 VRRE1ECPW20C VOLUME POT W20K
* VR102,104 32S00390 VRRE1ECPB50C VOLUME POT B50K

Now it gets slightly more twisted: they seem to have reserved the last 3 characters (2 numbers + 1 letter) in the VRRE string to indicate value in k.
But what values above 99k, which need four characters? (3 numbers + 1 letter)
I guess they drop the first one but print the string twice, the second one showing the full numerical value:

* VR106 32S01749 VRRE1ECPK00A VOLUME POT 1B100
Which I read as: 3 character code: 00A (should say 100A but no space reserved for first "1" digit) so they clear it by printing in a second string "B100" .
They "should" then print an third string specifically stating 100k, like the ones above, but probably their Excel page or whatever this software is based on, does not include the extra column needed.

Thatīs the only logic "explanation" I can find.

Can add the educated guess that 100k is a reasonable value for a volume pot plus the successful experiment of using b100k there.

Why would Ibanez print such weird label, even on pot itself?
Maybe Ibanez is using some old inventory control software, long on the tooth by now, but are stuck to it because itīs been used in thousands or previous products for decades.

Just an educated guess,of course.