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Author Topic: 5 String Washburn Rb2500 pot help!  (Read 1236 times)

Offline hexbreaker

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5 String Washburn Rb2500 pot help!
« on: January 19, 2017, 07:30:30 PM »
So i picked up this bass for fairly cheap, but the pot is busted.  Pulled it out and took it apart, the guts are all broken.  My question is, where in the world can I get a replacement pot.  I figured it would be easy to find but keep coming up empty.  I believe it is a 100k pot, but the numbers were wiped off the back.

anyone got a link or a part number or anything?  is it not a 100k?  it seems a 500k is easier to find.  Help?
heres a link to the picture of the bass with the pot in question circled.

https://drive.google.com/open?id=0B1ZMB4V1IZZUbjNXdFhSYlpLUVk

Offline Tony Raven

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Re: 5 String Washburn Rb2500 pot help!
« Reply #1 on: January 19, 2017, 10:40:20 PM »
If it's a passive pickup set, then according to Seymour Duncan it's likely 250K & goes something like this...


M1SDL; XB-400 (natural), XB-400 (burg), XB-500 (teal); X-10, X-33; D46CESP, WCSD30SCE; BT-3, BT-4, BT-6, JB-80; WS-4; WI-66V; Lyon LCT24; OS Autoharps

resident troublemaker: http://forum.frugalguitarist.com/

Offline hexbreaker

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Re: 5 String Washburn Rb2500 pot help!
« Reply #2 on: January 20, 2017, 08:17:28 AM »
thanks for the diagram.  It is an Active pickup tho.  Where did you find that diagram? 

Offline philpm

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Re: 5 String Washburn Rb2500 pot help!
« Reply #3 on: January 20, 2017, 05:38:38 PM »
Based on an old post from here that I found, if its the volume pot, it should be 500K.
On and off newbie player for about 20 years.

'08 Washburn WD-114SK (currently residing in Denver)
'10 Washburn WMJ11S
'09 Cherry Epiphone Dot
'13 Epiphone Thunderbird IV

Offline hexbreaker

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Re: 5 String Washburn Rb2500 pot help!
« Reply #4 on: January 20, 2017, 07:17:09 PM »
That's kinda what I found.  My dad has the bass and when we pulled the old pot out he says it said 100k but rubbed off.

The pot was for the bass or Tone I think?  Not the volume.  Just starting to play.  I have a Fender Jazz bass, but managed to find this one for 80 bucks. Should be an awesome deal if I can get it working.  First time I've ever tried to mess with any wiring really tho.

Is there any reccommended sites to buy from?

Offline Tony Raven

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Re: 5 String Washburn Rb2500 pot help!
« Reply #5 on: January 21, 2017, 10:23:58 AM »
Where did you find that diagram?
I reach first for Google Images. I'm very visually oriented, & it's easy to spot something in seconds.

if its the volume pot, it should be 500K.
:( Well... depends what you mean by "active" I suppose. Back to basics, then, before we get into difficult stuff..

Sure, an active circuit can have its volume controlled by a passive Vol pot. In that case, it would probably be 250K for a small pickup (Precision or Jazz type) or 500K for a big double-coil like the Music Man config. (In a passive config, each MM coil has its own Vol knob, & in that case each would be 250K.)

But if the Vol control is actually PART of an active circuit (rather than tagged on at the end before output), it is going to have MUCH lower value. I've seen anything from 25K down to 10K.

The pot was for the bass or Tone I think?  Not the volume.
In an active circuit, three pots is almost always going to be Volume + Treble boost/cut + Bass boost/cut. In a four-knob setup, it could add a Mid knob, or (like the later XBs) a pickup selector.
M1SDL; XB-400 (natural), XB-400 (burg), XB-500 (teal); X-10, X-33; D46CESP, WCSD30SCE; BT-3, BT-4, BT-6, JB-80; WS-4; WI-66V; Lyon LCT24; OS Autoharps

resident troublemaker: http://forum.frugalguitarist.com/

Offline Tony Raven

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Re: 5 String Washburn Rb2500 pot help!
« Reply #6 on: January 21, 2017, 11:16:20 AM »
This is what the StingRay active circuit looks like -- note the Tone pots are all 100K.



So far, so good.

Problem is, you don't show me what the internals look like. Here's how they're supposed to be --



The main circuit is attached to the centre potentiometer... about which you've said "the guts are all broken."

???

If the circuit board is busted up, then replacing the pot ain't gonna do nothing positive. Those basses haven't been made since like 2000, the RB2005 was replaced by a two-pickup 2502 the next year so the circuit might be different, & in any case the RB series was cancelled 2003 to favor the XBs. And the Washburn brand has changed hands at least once since then, with a major paring back of stateside build/repair facilities, so the likelihood of spare parts is tiny.

If the board is shot, you'd either need to locate one that's been salvaged, or rewire it as a passive (pickup from Bartolini, Duncan, Wilkinson, EMG), or replace what you've got (selling it on eBay or Reverb, of course) with something like a Duncan SMB-5DS system (<$219 on eBay) or add whatever pickup you want to their circuit (STC-3M3, $139) or maybe see if you can find an EMG MM5TW kit.

If you're fortunate, all you need is a new pot -- probably 100K -- & some careful soldering skills. I used to have four XBs, two of which have a "frozen" control that's locked up due to disuse & oxidation.

(My guess is the circuit allows a super-tiny trickle of voltage even when unplugged, so the battery doesn't wear appreciably BUT there's enough electron transfer to "plate" the wiper to the resistor plate. Anyone with one of these basses should ensure they work the knobs on a regular basis & maybe use some DeoxIT.)

As for parts: ANY GOOD COMPONENTS. Don't fall for the hype -- you can get a perfectly good pot for two bucks. Check Allparts.com or Reverb.com... or eBay or Parts-Express.com or Stewmac or even Digikey. Allparts deals mostly in passive stuff for modders, so they might not have anything under 250K.

Get a fullsize pot, not the mini (only useful in guitars where there's no room for a fullsize). If you'reunsure, stick to classic brands like CTS or Alpha... but on eBay you can get generics for 2/$1 with free shipping. If you want to go fancy, consider sealed plastic-body pots (the Bourns can be had for like $4, shipped).
« Last Edit: January 21, 2017, 11:50:10 AM by Tony Raven »
M1SDL; XB-400 (natural), XB-400 (burg), XB-500 (teal); X-10, X-33; D46CESP, WCSD30SCE; BT-3, BT-4, BT-6, JB-80; WS-4; WI-66V; Lyon LCT24; OS Autoharps

resident troublemaker: http://forum.frugalguitarist.com/

Offline Tony Raven

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Re: 5 String Washburn Rb2500 pot help!
« Reply #7 on: January 21, 2017, 11:46:16 AM »
While I'm here -- I hope you're not committing the rookie error of trying to do all the soldering inside the cavity. :o

That can be okay for a quick repair, but generally makes extended overhauls MUCH more difficult AND increases odd of burning the wood & melting the insulation & even burning the finish from heating up a pot body with the iron.
M1SDL; XB-400 (natural), XB-400 (burg), XB-500 (teal); X-10, X-33; D46CESP, WCSD30SCE; BT-3, BT-4, BT-6, JB-80; WS-4; WI-66V; Lyon LCT24; OS Autoharps

resident troublemaker: http://forum.frugalguitarist.com/

Offline hexbreaker

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Re: 5 String Washburn Rb2500 pot help!
« Reply #8 on: January 21, 2017, 06:47:27 PM »
Thank you thank you thank you.

I found that Diagram thru Ebay but was not positive.

The circuit board is intact.  The pot I unsoldered we cracked open and the guts inside the pot were busted.  The treble cut was working and the bass cut (the pot that was bad) just popped and buzzed when plugged in. The dial would spin and spin and spin and if you fiddled with it enough the bass would work but had a horrible buzz as if it wasnt grounded.  Like a turntable with the ground wire undone, annoying as all hell.

The issue with finding a pot was looking online there was so many but I wasn't sure which one.  Audio, linear or whatever.  My dad swears it need some kind of center indent or something.

From what I see any old 100k Audio pot should work and Ill check out those sites you mentioned. 
the pot in question was attched to the board.  Yes i pulled it all out and away from the cavity before heating it up.

https://drive.google.com/open?id=0B1ZMB4V1IZZUaE5WelItVEFKbXc
« Last Edit: January 21, 2017, 06:54:42 PM by hexbreaker »