Aria wiring repair issues

[ViVino]

So I have been given an Aria CTB-2 bass to repair due to a pot being completely broken, will not turn or anything.

 

Firstly, trying to find even a schematic on this thing is crazy hard to find ! So I open it up and it has a really interesting active/passive circuit. It looks like it has a vol/tone & pickup selector, followed by and active/passive switch and then has a really cool dual pot with a board attached. 

 

I've never heard this working, but I believe it is a similar setup to the fender Japanese power jazz / jazz specials which had an interesting active tone pot that cut the bass one way then boost the treble the other? Creating an interesting mid shift as it swept ?? (Someone can confirm and correct me on this if I'm wrong)

 

So, not surprisingly the active pot is the broken one. It is a dual pot, 500k, but it is A/C (top and bottom) so one side is log taper and the other side is reverse taper. Then to top it off it's a strange reverse mounted panel mount/PCB connections for soldering. I have been looking to source a direct replacement, but, finding even a dual 500k A/C seems difficult, let alone anything that would mount directly.

 

Any ideas ?

 

 

[itu]

That pot clearly has a centre detent mechanism. May be downright impossible to find similar. Is there something wrong with it?

[ViVino]

7 hours ago, itu said:

That pot clearly has a centre detent mechanism. May be downright impossible to find similar. Is there something wrong with it?

Yeah, it's just broken .. it won't turn at all, like the pot has seized somehow due to some damage along the road

[itu]

At all? I would open it - carefully - to find the issue. WD40 to the axle could help to turn it. Or not. If the latter, you have to open the case.

 

That centre detent mechanism is the first to be opened (after removing the pot from the bass). You can see it has been hit with a chisel (two grooves at the end of the axle). Try not to remove any material, and you may be able to put it back.

 

Opening the pot casing is usually the easiest part, if you do not ruin the metal parts. Take it slow, and put all parts to the same order as you remove them. More table and more light will be helpful.

 

If all parts are in good condition, rebuild the pot. Use deoxit to clean carbon tracks. Excessive oil is bad, and does not belong to the tracks. Only to the axle. Make sure the contacts are functional. 

 

You should have found the issue that prevents turning by now. If something is broken, find another pot from the same manufacturer, and take spare parts from that. Good luck with your journey.