Help with potentiometer.

[HellasTechn]

Dear friends.

I need to replace the volume potentiometer on a DENON PMA-280 audio amplifier.

The old one is an ALPS 4 pin 30kbx2.

I cant find the same one. Any ideas ?

Could i use a normal 30k double potentiometer ? but then again what is pin 4 used for ?

Here is how it looks like from inside.

THANK YOU !!!!

 

[Arouse1973]

Not sure what the fourth pin is for. It might be bass boost or something like that. Make sure the POT is a log type also. I would have thought you could find a replacment. Got any pics?
Adam

 

[Frenoy Osburn]

The 4th pin is usually for loudness control.

Have a look at this http://www.angelfire.com/electronic/funwithtubes/Amp-Volume.html
http://www.angelfire.com/electronic/funwithtubes/Amp-Volume.html
Toward the end of the page. If it's difficult to find an exact replacement, you could find a regular 3 pin POT and use a voltage divider for the 4th pin.

 

[HellasTechn]

I am thinking of useing a 2x30k potentiometer and 2 15k resistors connected to pin 1 and 2 one side and pin 4 other side. maybe that would work.

 

[HellasTechn]

The 4th pin is usually for loudness control.

Have a look at this http://www.angelfire.com/electronic/funwithtubes/Amp-Volume.html
Toward the end of the page. If it's difficult to find an exact replacement, you could find a regular 3 pin POT and use a voltage divider for the 4th pin.

How would you suggest that i could do that ?

 

[HellasTechn]

Note that i fould 47K and 22K potentiometers....

I guess the 47K would be better ?

I even tried soldering a 4th pin on the resistive plate but no luck it can not be soldered