Help Wiring a Replacement Potentiometer for Sonic T

[Smokehouse Bob]

Can someone explain the wiring sequence for connecting the amp to an ALPHA 50 K (3 post) pot? This would be using the "5" available white wires off the stock connector. I don't have a double pot on hand and would like to use this one but can't figure out which wires are soldered to which post. I've tried the obvious websites, but all references I've found refer to the ALPS double pot (which I don't have and would surely cost me more than the amp to order!).

[Smokehouse Bob]

She powered up once with sound in the left speaker, nothing in the right. Rechecked all solders, figured I wired the pot wrong. Unsoldered the pot and tried numerous permutations, no sound only a low buzz in each speaker. LED lights up and no smoke. Did I kill it?

[PCHuggs]

The pinouts for the T-Amp control are in THIS thread.

This is from Motherone's description:

Originally Posted by Motherone

=============
Connector #1:
=============

(from Left to Right):
V + Ro Lo G Li Ri

V = switch 12volt out
+ = switch 12volt in
Ro = to volume from right channel
Lo = to volume from left channel
G = ground
Li = from volume control to amp left channel
Ri = from volume control to amp right channel

Best regards,
PCH

[Smokehouse Bob]

Thanks! Well, I think I screwed up with this amp. No smoke, but no sound either. Either this Alpha pot I'm using must have been damaged when I hooked it up last night, I am connecting it incorrectly (5 wires to 3 posts?) or I fried a perfectly good T.

Motherone (I believe) previously suggested ground may be left, input on the right, and L/R in the middle. That isn't working on mine, so back to the bench I go. I measured the pot using a DMM and got 50, but now what to do? If I had only gone with a double pot in the first place (as described by others), I wouldn't be here now. I'd be enjoying the tunes that this amp put out while encased in its original plastic box. Using what is cheap/readily available in components can be a downfall.

[PCHuggs]

The schematic from Mike Mardis may help -



You need two potentiometers (ganged for stereo is good).

The ground goes on one end, the input on the other, and the ouput (to the amp) from the middle.

Go back to the original potentiometer and hook it up again. This way you can tell if the amp or your pot is is the culprit.





PCH

[Pano]

Originally posted by PCHuggs
[This is from Motherone's description:

Unfortunately this is reversed. It should read:

(as seen from the top - Left to Right)
V+ | Vin | Ri | Li | G | Lo | Ro

V+ = to positive power rail
Vin = from power connector
Li = to amp left input
Ri = to amp right input
G = ground
Ro = to volume from mini jack
Lo = to volume from mini jack

I wonder if we can get a moderator to correct the post? It would be a shame to leave it reversed.

Hooking it up backward won't hurt, but it won't work!

[Smokehouse Bob]

I can read the pinouts with no problem using the old pot PCB. It's the application of these 5 wires to a 3 post pot that has me confused. Are all the white wires going to the pots, then 1 extra wire each going from there back to each input RCA center pin (Li and Ri)? I understand left, right, and ground....it's the other 2 wires that I can't sort out.

Thanks for your help, I know you are really trying hard to coach me out of this but as often suggested by others here I am "obviously in over my head" and will pitch this formerly nice sounding amp in the garbage and walk away with 30 less in my pocket but richer for the experience.

[BWRX]

Perhaps this diagram by amt will help clear things up.

[audio1st]

You will only get mono from your 3 pin pot. My dia' is attatched and you would have to join Li & Ri to one pin and Lo & Ro to the other (middle). Ground to the third pin.
You should have bought a £15 pot!

[Pano]

audio1st, I like your diagram! Not the prettiest but it sure is clear.

Thanks for that. Sometimes photos just work better.