BTW, a Maverick owner who I have been in contact with got the following information from the Xiangsheng factory on how to defeat the volume control of the line out by soldering two spots. Not as simple as a jumper switch, but still possible for anyone handy with a soldering iron.
It will involve 4 steps (see attached picture):
1) You need to remove the front panel PCB ( not the main PCB, just the small PCB attached to the front panel).
2) You need to remove the volume control switch.
3) Below the volume control switch, when the 2 points are connected in the place A and B, you can bypass the volume control.
When the 2 points are connected in the place C and D, you will enable volume control.
4) After you disabled the volume control on PCB, solder the volume control switch back on, put the front panel panel PCB back to the case.
So now, the only real differences out there are price and aethestics (and upgraded tube).
It will involve 4 steps (see attached picture):
1) You need to remove the front panel PCB ( not the main PCB, just the small PCB attached to the front panel).
2) You need to remove the volume control switch.
3) Below the volume control switch, when the 2 points are connected in the place A and B, you can bypass the volume control.
When the 2 points are connected in the place C and D, you will enable volume control.
4) After you disabled the volume control on PCB, solder the volume control switch back on, put the front panel panel PCB back to the case.
So now, the only real differences out there are price and aethestics (and upgraded tube).