He uses cheap bullshit parts sourced from Ali-Express for his power amps. I've had to fix a few for a buddy because they were noisy and not grounded. Even with some fixes they were never quite right. Noisy and unreliable. He epoxies his screw heads and puts labels like "UNAUTHORIZED OPENING OF DEVICE WILL VOID WARRANTY!". He obviously doesn't want people seeing that he uses cheap bullshit. In some of the amp builder/modding circles he is not talked about positively.
Modding a bandmaster to have high gain is similar to a IIC+, it involves cascading the channels. You can hit up any of the known and reliable amp modders out there to do a mod like this.
Here's his pedal power amp thing with links of his circuit boards. I've seen a few of them and they were all like this.
https://www.aliexpress.us/item/2251832719836411.html
https://www.aliexpress.us/item/3256803507710062.html
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