How to daisy chain two GK MB 115's
 

I have them set up parallel using my Line 6 M5. Works decent except for adjusting tone and volume. I have them stacked so I can't access the controls on the bottom amp.

Sooo...

How can I run the amps together to be able to use the controls on the master amp to control the slave amp.

Remember the MB 115's have two inputs, headphone jack, line in and XLR out. That's all. No effects loop(sucks) and no preamp out.

While we are at it, could I hook yp my Ampeg BA 108 in this mess with it's effects loop to use it as a preamp for the other two?

Please help!!

Use an amp lift to get them off the floor about a foot and lay then on their side.

It would take some experimentation to see what works. You could get a hybrid XLR to 1/4" cable and run out of the direct out to the input of the second amp. You would have to set the second amp at a level where you can get some volume but not so high that the direct out of amp 1 distorts the preamp of amp 2. You also have to experiment with which control (gain or master) of amp 1 changes the direct out level.

As for driving both with the Ampeg, I think it has a preamp out you could use. Just get a y cable and run from the preamp out to inputs of both MB 115's. You might also be able to run from the preamp out of the Ampeg to one input of one of the MB 115's and then come out of the other input of that MB 115 to the input of the other MB 115. Since the input jacks are in parallel, whatever signal you put in one jack is present on the other jack. Upping the level on the Ampeg should raise the level of the preamp out and drive up the volume of both MB 115's, but it will also turn up the volume of the Ampeg. I guess you could plug some headphones in the Ampeg and turn it into a silent preamp.

Here's what Ampeg's owner's manual says about the preamp out
This output can connect to external power amplifiers, or powered loudspeakers, as long as they have their own input controls to adjust the volume level.

Stack them "sideways up" so the control panels wind up on the side of the stack.

You may be able to jigger the XLR out to the line in of the 2nd one but unless the line out is an actual line signal it would need a mini mixer to match up the gains.

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Well said :smug:

You can’t. Two GK MB115 bass combo amps can't be "slaved" together.

+0.1
Could be the master doesn't control the line out, if that's the case no master slave control.