A few good options for adding a remote are available from diycables.com. You can use a DACT stepped attenuator with a motor provided by Bent Audio or you can use a motorized Alps pot. The first is about $400 whereas the second is about $100, and although most tend to favor the first option, not everyone agrees with that. Both require an external DC power supply, and I suppose one could shield the PS cable going in to the board if needed. Many manufacturers seem to argue that remote controls make marginal audible noise, though in my readings I've typically seen this statement refering to when the motor is moving. And as long as it's just marginal and limited to the changing of volume, who cares! Unless someone else knows of a reason to avoid doing this, I think you should go for it!
The methods outlined above are for the direct swap-out approach. I had a buddy add a whole DACT attenuator setup after (downstream of) two independent volume controls on a dual mono setup. When the volume controls are up to full, they are essentially out of the circuit. That is a great sounding preamp, though (of course) it would be preferable to substitute the old volume controls with the new one. Another more radical substitution approach is to use the Welborne Labs digital remote volume control, which uses relays to change stepped attenuators. This is not a standard shaft-and-knob approach, so it requires major modifications to the chassis. Too much messing around, but good if you're building your own preamp!
The only real downside I can see is that (some) people are less likely to trust mods if you are planning on reselling the equipment. Also, if you use the DACT approach, make sure that you add adequate support beneath the motor - that's a rather large weight held out far from the attachment point between the shaft and the front face of the chassis.
The methods outlined above are for the direct swap-out approach. I had a buddy add a whole DACT attenuator setup after (downstream of) two independent volume controls on a dual mono setup. When the volume controls are up to full, they are essentially out of the circuit. That is a great sounding preamp, though (of course) it would be preferable to substitute the old volume controls with the new one. Another more radical substitution approach is to use the Welborne Labs digital remote volume control, which uses relays to change stepped attenuators. This is not a standard shaft-and-knob approach, so it requires major modifications to the chassis. Too much messing around, but good if you're building your own preamp!
The only real downside I can see is that (some) people are less likely to trust mods if you are planning on reselling the equipment. Also, if you use the DACT approach, make sure that you add adequate support beneath the motor - that's a rather large weight held out far from the attachment point between the shaft and the front face of the chassis.