My preamp doesn't have a balance control, but, having moved things around in my listening room, I need one. Is there an "audiophile" grade external balance pot I could get and if so how would it be connected?
There is no such thing made commercially, that I have ever seen, and a balance control really needs to be integral to the internal circuitry.
If you have an imbalance, however, you might be able to put an attenuator (a variable resistance) between the preamp and amplifier in the channel you want reduce the volume of. The resistance value of the variable resistor would probably need to be about 50K ohms or so, depending on the input impedance of your amplifier.
With an integrated amplifier or receiver where one does not have access to the signal, however, that is not going to work either. Putting a pillow over one speaker is probabaly not a good solution, either....
I've never seen such a product. Your solutions as I see them would be:
1. Change to a preamp that has a balance control. This solution also has the added benefit of giving you an excuse to upgrade.
2. Change to an amp that has an input sensitivity adjustment. See number one for added benefit.
3. Reposition things (either speakers or listening position or a little of both) so that you have a more symmetrical set up. Sadly, this doesn't offer the the opportunity to upgrade because you "have to."
OK, I may be FOS, but how about a couple of Alps RK50's between the preamp and the amp?
We've all forgotten, including myself to ask what's in the system? Knowing that might affect what would be considered an acceptable solution.
These will do the trick
4db steps? That's huge. 2db might do it but that's still pretty coarse. In my experience even 1db is audible, though just barely. I'd think that for subtle adjustments you'd want something that did 1db, maybe even 0.5db.
If you have a really revealing system my gut feeling would still say that using an attenuator on one channel and not the other could cause some sonic issues. If it were me I might ALSO use one on the channel that did not need any attenuation and run it wide open just to keep the two channel's signal paths as identical as possible. That might sound a bit extreme but when all of the small things in a system are done right it really adds up to big sonic results