Anthem Pre 2L: Potentiometer

[markmay]

I am having a problem with the replacement of the potentiometer in my Anthem preamp.
I have replaced the volume control pot with an Alps RK27112 100K blue velvet. This is the same pot value that was in the Anthem from the factory.
My problem is that I get about 90% of the volume when it's only turned up to about 5% of the pot rotation travel.
Should I consider a pot with a different resistance value?
I have switched the gain selector to lowest level (8db).
Any suggestions would be appreciated.

 

[eclectic2k]

My problem is that I get about 90% of the volume when it's only turned up to about 5% of the pot rotation travel.

assuming nothing is mis-wired...
it sounds like you have used a linear taper pot in place of what should have been an audio taper (log)

take a look at the RK271 spec sheet for the details and a nice graph of travel vs output. (or just do some googling) The taper is denoted in the full part number of the pot if you have it handy. (refer back to the spec sheet for the numbering system)

With a few extra resistors to form a sort of extra voltage divider you can make the lineartaper approximate log taper, or you can buy a new pot.

-CK

 

[markmay]

CK,
Thanks for the info.
I looked at the specs and it is an audio log taper pot, however it does seem to taper more like a linear pot. The factory pot was guilty of similar performance, but not as bad. Will the resistor application work on a log taper pot? What do you think about channel bleed over, since both of the outputs would now be connected so close to the ground. Would the current prevent the bleed.
Thanks,
markmay