Fender Rumble 500 v3 Pot Replacement

Ask your question in the Fender Rumble Club..people in there may be able to help you. This is the link here below.

Fender Rumble Club

 

It looks like a 16mm Alpha vertical PC mount pot.

Check here or here. Its value is 500k, audio (log) taper.

 

It's a custom pot, needs to be ordered through a Fender service center.

Since that's a double sided PCB with plated through holes, you need to be very careful not to damage the plating.

 

This is a very good place to buy Fender parts. They are a Fennder service center and parts distributor. Send them an email with all the details. They should be able to help you.

Fender amp potentiometers

 

With that back lug, I kind of figured that. Probably custom length on all the legs, too.

 

I don't know, but Fender buys pots by the millions so they can get whatever they want/need.

 

It’s a style that Fender uses. It adds stability that helps prevent broken solder joints.





Although these type of frames do a better job but require enough space to mount.

 

2 different orientations

 

True. I've seen both orientations available. With all the metal, people find the bottom one difficult to unsolder. I snip the metal frame, then unsolder the snapin pins.

I use a lot of these Alpha pots, with a properly nut in place on a firm plate, it's hard to imagine how a top mounted pot could break like in the image from the OP. Folks always seem to find a way.

 

I see a fair number of PCBs ruined by folks (including some techs) who have no idea how to properly remove parts without damaging the PCB. A simple repair can easily turn into an expensive re-work or sometimes beyond economical or reliable repair.

Yes, always cut the part out and remove (GENTLY) the pins one by one. Suction is usually much gentler on the pcb than wick, but either can become disastrous with "ham fists".

 

It's a spider style pot, I found several audio taper ones but finding an audio taper 500k eluded my 5min search.

 

Note that there are different terminal heights, bushing heights, shaft lengths and styles within this series. All of these need to match, which is why I suggested contacting an authorized Fender service/parts center.

 

I'm not actually disagreeing with any of that, just stating that you can find them outside of a service center with the correct physical specs.

It's not like we're talking about finding esoteric milspec parts that aren't in production anymore.

 

Not necessarily, they are build to order parts generally and not available or shocked off the shelf. I use some of these types of parts which are only available in OEM quantities as built to order parts.

 

Has anyone actually found a replacement for this a30500k Pot? I have a fender rumble 200 with this exact same problem. I’ve done everything everyone’s suggested in this thread with no success. I’ve called three different fender service centers and everyone told me they cannot sell me a fender part. I’ve emailed Darren Riley and received no response. Any help is greatly appreciated.

I would just drop in a 500k pot and call it a day but it’s the 4th leg that confuses me. If there’s a way to modify a 3 leg pot to work in place of the 4 leg spider I’m open to that too, all suggestions welcome. Thank you.

 

The 4th leg is not used... it MAY be connected to something internally but it's wired as a conventional pot.

The 30A taper is somewhat custom, it may be easier to find as a 20A taper.

IIRC, the PCB needs the mechanical support of this pot.

Service centers in general are getting away from selling parts to end users, it often ends with an unhappy customer who still has a broken amp bitching to the service center about either the part being defective (not), or that it's their fault that the part didn't fix their problem, or they created new damage and ruined the amp completely. To sell a $5 - $10 part then have to deal with this is not a professional shop's core business. They will however repair it for you with the correct parts.

 

For that application a 250K-A taper pot will work fine, the spider style is available as a Peavey replacement part BUT it's a spline shaft and the bushing is different and that means that the height is also likely different. It's critical that you have the proper dimensions. Generally, Fender uses D shaft and the standard zinc cast bushing. The height is specified by the designer and is ordered custom (along with the bushing).

 

Appreciate the feedback, I purchased a 500k d shaft pot from tube depot and I’ll just run wire from the lugs to the PCB. I really don’t want to have an odd knob on the amp so I passed on the peavey 250k.

 

Update: I installed the 500k pot into the amp connecting the lugs to the spider legs of the previous pot. The d shaft is reversed so the knob was on backwards. I used some almond and black touch up to reverse the line on the knob… seemed like best possible solution, there’s no way I was going to wire the pot in backwards. Tried firing the amp up and got a real blown output. Took it back apart and noticed FE100 was totally fried. Ha, this is the way my lucks been goin lately. I threw a wire in there connecting to left over copper tracings, closed her back up and she’s workin like a champ now. Appreciate the help!