Sure. There are 2 connections on the back of the Balance control. These will have 2 wires fed to them from the back of the chassis. Trace those wires back and you'll see they are part of the AC input wires from the AC cord. Some of those wires will also go to the outlets on the rear panel originally intended to handle other amps and gear.
Solder a wire between the 2 connections on the back of the Balance control. In other words, short them out. What this does is to render the ON/OFF knob useless since the unit will not come on as soon as you apply AC power to the AC cord itself.
What you are also doing is to provide a low resistance path for AC power without the current running through the switch on the Balance control. You want to leave the ON/OFF switch itself in the OFF position to keep the switch contacts open so there is absolutely no current being run through the contacts. This forces all AC current to go through the short you just installed.
To power the MX-110, then, just use an external power strip with its own switch on it. This is what I do. Works great and the ON/OFF-Balance control does not run the risk of arcing contacts which, when hot enough, can burn up the Balance pot.
Hope that helps.
Cheers,
David