I need help as to how to wire the two together. The volume pot alone is easy , I can just take the wire leads from the original pots. But I'm not sure how to wire in the balance pot in the curcuit and I understand there are several different ways to do so.

Can anyone draw me a point to point drawing, or send me a schematic with the best way sonically to wire these up?

Thanks for your help, Peter

note: each post has three leads, numbered 1,2,3 per channel.

What this does is to make clockwise rotation of the balance knob turn the left channel up and the right channel down. Counter-clockwise rotation does just the opposite.

So I'm a little hesitant to wire this up until I'm confident I know which wire goes where. When you say input and output, I'm not sure on the stock pot which is which. I do have a schematic but not sure of the signal flow.

I'm not sure if I go from the amps (out)( From the orig. pot ) to the new volume pot then the balance then back to the amp?????

I hate to ask you but what I really need to feel confident to do this is to ask you to draw me a picture, form the nine different lead/contact points per channel.

3 leads from the orig. pot, 3 contacts on each channel of the alps volume pot and 3 contacts on each channel of the alps balance pot.

Thanks for your help, Peter

Internally, the potentiometer has a resitive substrate with connections on both ends, pins 1 and 3. It also has a wiper that can be moved along the substrate, pin 2.

The audio signal flows out of the preamp circuit to the potentiometer. The resistance across the potentiometer is the load to the preamp circuit. One side of the pot is connected to the preamp output (input to the pot) and the other side is connected to ground.

The wiper rests on some point between the signal side and ground. This makes two resistances from this point, one to ground and another to the preamp signal. This forms a voltage divider, and the signal level depends on the position of the wiper.

To wire this up properly, you will need to know what wires go to what points in the circuit. You need to identify why lines are ground, what lines are from the preamp output and what lines are inputs to the next stage.

I appreciate your excellent discriptions, etc...

Peter

So I'm hoping I don't have to tear back into the chassis of this old amp as it's quite messy. I'm hoping that maybe I only need to change the wiring on the balance pot. But I'm not going to doing anything until I hear back from you.

Thanks, Peter 310-465-5629

I spent a great deal of time studing the circuit to make sure I did it right the first time. I felt very confident that I was wiring these pots up exactly as you had advised me. Using all three contacts on the balance pots. Now you suggest I lift the grounds ?

You can see why I had first hesitantly asked if you might draw me a picture of the what should be fairly simple wiring. This old amp is very messy inside and I don't want to experiment and possibly do damage to this very special amp of mine.

I know I can just forget the balance pot, wire up the volume and hope the left and right levels match, but... I spent a lot for that balance pot and of course would like to use it in my system.

I'm sure there is an exact correct way to do what I need and I was hoping you could help me with that or perhapes refer me to one of the other audio guru's that may be able to assist.

I do so appreciate your help.

Sincerely, Peter

Honestly, the balance pot should be at least twice the value of the volume pot and it should have linear taper. Using the wrong pots is probably what's causing your problem. If you want to replace a 500K volume pot with a pair of pots, one for balance and one for volume, you probably should have gotten a 150K volume pot and a 350K balance pot. The volume pot should have logarithmic taper, the balance pot, linear taper.

Wire them like this:
LEFT RIGHT

in 1 ___ in 3 ___
| |
|2 |2
|----- 1 |----- 1
350k | | 150k 350k | | 150k
balance | | 2 volume balance | | 2 volume
| |---- out | |---- out
| | | |
gnd 3 ___|_____|____ 3 gnd gnd 1 ___|_____|____ 3 gnd

If you don't feel comfortable doing the job, maybe you should take it to a shop. They can do this for very little money.

Any suggestions? Could it be just a matter of switching the wires on the pot?

It seems to work fine. And sound fine. But sure makes me wonder if it could cause some problems.

Happy New Year! Peter