Mic input on Loudbox
 

I have this new LR Baggs M1 passive which isn't a real hot pickup. I have been running it through a Behringer ADI21 into the mic input on my Loudbox Mini. (We're talking just for home use here.) I am getting a very nice sound and A LOT of volume. Compared to plugging it into the regular guitar channel with the ADI21, I get a nice sound also, maybe a little better, but not near the volume. I have to turn everything up a lot. Why would that be and is it OK to put it through the mic channel?

I have noticed also that in the guitar channel, The A string starts vibrating and feeding back until I hit the phase switch on the amp. Maybe my strings are too close to the pole? I didn't think that a phase switch would matter with a magnetic pickup?

Enlighten me please.

Well, the M1 is passive... so the signal it sends is high impedance, while the mic input on your Mini is low impedance... running it through a different unit (the Behringer) and out must be giving the signal the transformation from high>low - that's why it works through that input.

When you go into the regular channel on the Mini, the signal from the M1 is again "stepped down" to low impedance, BUT the channel "wants" to hear a high impedance signal... so you have to jack the controls around to get the sound you want... in essence, the input signal is weak when compared to what the input on the amp wants to see...

As for the feedback? Well, welcome to the Wonderful World of Amplifying Acoustic Guitars!