Ancient NAD 114 stereo preamplifier service manual?

Hello!

My old NAD 114 preamplifier has pot problem. Does anyone have service manual or know what potentiometer it has behind volume knob?

I'm just lazy and I don't want to take it off the rack just for checking the pot. Besides I like to have documentation for my devices.
 
Alps 20KAX2

I found the service manuals in a few places... the pot is 20k Logarithmic

Japan Alps 20KAX2 LOG type Volume Potentiometer

I have the crackling problem - but I thought it could be caused by DC in the signal path - cos I got a crackling in the selector switching...
...and, apparently, NADs have a problem with the white goo turning brown and going conductive - but the 114 hasn't got a lot of that in the signal path except in the phono and headphone sections...

I'll tear my brown goo out and make lots of measurements before I consider replacing the pot.