I'm a novice player, I ordered the MPA40BT and have no complains.

One thing to note, I was using only XLR cables most of the time and without some amplification between the stick and the speaker I couldn't get any decent volume out of it.

But if you use the TRS cable included with your stick you'll get a lot more volume. Apparently the speaker has more gain on the TRS inputs than the XLR pins.
(Granted it's a combo socket).

So, if you have no DI box/mixer or other preamp, use the TRS jacks with this speaker if you want volume.

Apologies for any missed terms. I'm a complete novice at stick and electric guitar topics. Meanwhile, I'm happy with this combo amp. I haven't used it on battery-only mode, it's just what I practice with.

- Dave