Busted Tone Pot on an Aria igb805

[kumimajava]

Having acquired a curiosity for the 5th string, and perhaps too much sake whilst perusing Yahoo-auctions, I'm now the happy owner of an early 90's Aria Prio II IGB-805.

The bass is in good shape, and the tone sounds good, excepting two niggles:

1. there is a lot of noise coming through the signal when the "treble" tone pot is engage. When i roll back the treble all the way to 0, the noise goes away. (it's the one on the lower-left, in the first photo).

2. There is likely a shielding issue, since the bass hums, but a bit less so when I touch the strings. On the other hand, if i touch any of the screws on the electronic cavity, the hum intensifies... so a grounding issue as well?

I've had a look around online, and I can't find much about Aria electronics. A pic of the preamp etc. is attached. Would it make sense to try to swap out the tone-pot, or should I just get a replacement preamp? If replacing the tone-pot, would any of you have an idea as to what k-ohm values Aria was using?

Or - if the shielding issue is the main cause, is the tone-pot just a red-herring (turning down the treble filters out hiss/noise?).

Apologies for the obvious noob questions here - but would appreciate any input. I know I could probably take this issue to a shop, and get it sorted there, but since this is a "learning" instrument for me, I wouldn't mind learning a bit of the diy/maintenance that goes with it

 

[kumimajava]

Just a quick follow-up, in case someone comes across this post in the future, trying to solve a similar problem.

I got some cheap copper shielding tape, and figured I'd try shielding the electronics & pickups cavities to see whether that helps, before actually mucking around with the soldering iron.

Shielding the electronics cavity reduced the hiss/noise by around 80%, and the pickup cavities about 15%. As far as I can tell, the bass is now almost silent. Moving the pot around does cause a bit of crackling, but I expect that's normal for a pot that age. I'll leave it as is, for now.

No pics of the shielded cavity, sadly, because it looks hideous (was a quick & dirty attempt just to see whether it works), but if I do re-do it properly one day, I'll update the thread with some photos.

Overall, very happy with the bass - very comfy to play, and sounds nice and clean

 

[mech]

Moving the pot around does cause a bit of crackling, but I expect that's normal for a pot that age.

Get some quality pot cleaner, have the bass with the knobs down, squirt a little cleaner in the slot by the legs on the pots and rotate the knob it's full range a couple of dozen times.

It's good to be able to do the shielding and fix things yourself.

 

[kumimajava]

Thanks for the recommendation - didn't know they had a special cleaner for that Will see what I can find.