Removing a Jolida 502 Balance Control

[tbentley]

I'm deleting the balance control on my Jolida 502A. Attached is the portion of the schematic (it's a 302 schematic, but this circuit is the same).

Also attached is a pic of the vol-bal board. It'll be deleted, since I'm also replacing the volume control with a TKD unit (but that's easy).

Can anyone advise as to the changes in the circuit to remove balance? Sorry for the ignorance, but it's been 30 years since I did this last.

Thanks!

 

[artosalo]

Just take the RW2 away, or cut the copper foils at both ends of it. Nothing else is required.

 

[tbentley]

Just take the RW2 away, or cut the copper foils at both ends of it. Nothing else is required.

Thanks, you were right.

I removed the old carbon volume (100K log) and balance (100K) controls, replacing them with a single TKD 100K log pot.

Outstanding improvement.

But: dropping the old carbon stuff out decreased the overall resistance of the circuit, making the new volume control more sensitive that I like.

Question: can I put a precision resistor in series with each of the input lines of the pot? If so, would you suggest 50K, or something else?

Great forum, especially for newbies.

 

[rayma]

can I put a precision resistor in series with each of the input lines of the pot? If so, would you suggest 50K, or something else?

With a series 50k you'll lose 3.5dB of gain. To minimize loss use a 10k instead.

 

[alexvaker]

Hello from Athens Greece.
Iam facing same problems with my pots.
So... i Have to remove rw2 resistor, then remove completely the balance pot, and replace with a MONO TKD 100k volume pot with only 3 feet?
and where i have to solder the 10k in the pot inputs? one resistore in series in each leg?
Thanks for your help, and sorry to bother.

 

[Tom Bavis]

Alex, you need a dual pot - 100K log taper.

 

[alexvaker]

Thank you Tom.Already done!!