NAD 917/2100 problem

[theblackbear]

Hi,

Please excuse if this has been covered, but I couldn't find an answer to my question using several search criteria.

I'm using an NAD 917/2100 PE combination to push two JBL studio monitors. I've had the amp and pre-amp since new. Recently one or the other channel has been going dead. Turning the volume up usually causes the dead speaker to come back on immediately, although sometimes it takes two or three rotations of the volume control to get it back on.

I assumed it's a dirty pot, but reading some of the forums I've seen discussion of other problems these units experience as they age. Any recommendations greatly appreciated.

Thanks

~ Blacky B.

[lineup]

you should

1. disconnect, de-solder, the volume potentiometer

This is usually one DUAL Logaritmic special 'volume pot'.

People told me, that there are some spray or chemical oil/grease
that can be used onto the carbon resistive surfaces.
To fix them a bit.
If is only dirty carbon layer and/or moving metal wipers
you may get it work perfectly alright again.

Otherwise you could consider find one Replacement pot = same size & value.
First search should be at the closest NAD website = Support/Service/Contact.


2. dirt or just worn out and damaged carbon layer.
Potentiometers, especiall those most used = The Volume Control Pot
will have a limited life.
This is specified as:
---> minimum guarantee,
Number of turnings (like 5000, or 10000 operations)

Cabon, Cole, as in one carbon pencil pen you write with
(charcole also used by painters when drawing in black & white )
will be scratched and carbon will go away, like black dust.

Same way with carbon layer pots.
They will eventually no more have a carbon contact to the metal wiper.
And when this happens, there will not be any sound from this particular area of the cole layer.