Aria Pro II XRB series electronics restoration

[Jimi Windmills]

Hey everyone. I have an old Aria Pro II bass from the late 80s. I got it as my first bass when I was 14. I am 40 now, and would like to restore it to working order. I have hunted high and low for schematics and have come up short. I did find an old post here from many years ago where the OP just ended up rewiring with a passive PJ setup and another where the wiring harness basically fell apart.

My wiring harness is mostly intact, so perhaps I can get some help with a couple of points and then it will be available for XRB owners in the future.

For a start, I need some help identifying components. Secondly, I need help finding where a couple of detached wires should be re-attached.

This is the wiring. I'm sorry it's probably not a good schematic, but I hope it is enough. The ? are disconnected cables. I assumed the J-pickup goes to the 3-way switch and the DC negative to the input jack. But either other components need replacing or I was wrong.

Most the pots are seized and need replacing. Perhaps other parts too. Can anyone identify these parts

This pot with 6 legs

What type of pot is this

What type of output jack is this?

 

[Matt Liebenau]

The first one is a dual gang circuit board mount potentiometer. The second is a standard potentiometer with a switch on the back. The output jack is a stereo or TRS jack. I don’t know about value or taper for the pots. There would have been numbers on them originally. They might still be legible. If not, you’ll have to find an original schematic or test with a multimeter. From your diagram it appears the other wire from the J style pickup should be connected to the open lug on the switch. The battery negative would also typically go to the ring terminal on the output jack. The circuit board looks pretty corroded in the picture where we can see part of it and I’d be concerned about it working at all. If the bass was on my bench I’d probably disconnect the pickups and temporarily attach them to an output jack or cable and make sure they work. If they do, it might be less hassle to just replace the preamp.

 

[Jimi Windmills]

Thanks a lot Matt, glad to know I was correct with the location to re-wire the J pickup and Battery negative.

I have a question about the dual gang pot. It has a rotating back with a mid position clicker. I assume that once I measure the range, I could replace it with a pot without the clicker, if I can't find a similar replacement. Also, the J pickup was soldered to this rotating part... seems like a failure waiting to happen. Could this have been soldered to the side of the pot instead of the back?

Edit, tested pickups on a lead and they work, so that's a good start

 

[Matt Liebenau]

I’m not 100% what that board does. I’d guess some kind of a boost / cut like midrange or a combined bass and treble so the detent on the pot would be center. It should work with a pot without the detent you’ll have a harder time finding the middle position. I don’t like having the ground attached to a moving part like that. It should be ok connected to another ground point but again, I’m not completely familiar with those electronics.