Slaving a Markbass LMK II to a Mesa Walkabout heas

[Lobaw]

Hey there TB electronic wizards:

I was hoping I could get some guidance on how to properly slave a LMK II to my Walkabout head. I don't want to blow up anything.

If it's easier to slave the Walkabout from the LMK II, that would be fine too.

Thanks.

[RickenBoogie]

What spkr cabs are you using, and how many? "Slaving" is usuallyt used with multiple cabs, each amp having it's own. You could also run them stereo. But first things first, what are the spkr cabs? and the rest of the rig?

[Lobaw]

I'm running 2 EPI T-112's (8 ohms each) off of the Mesa Boogie and wanted to slave it to the MB to run a single Acme Low B 2x10 4 ohm cab, or 2 more 8 ohm cabs. I'm kinda stuck with this configuration since the Low B demands so much power, but wanted to take advantage of the tube pre in the Mesa Boogie. I've got a few other cabs which are variously 8 ohms and 4 ohms. I don't want to run the Mesa below 4 ohms, although I hear, unofficially, that it can go down to 2 ohms (not according to the tech I spoke with at Mesa). I do have an IAMP 800, which goes down to 2 ohms, but I'm retiring it and will be selling/trading it for something else. It will be up here on TB soon. Thanks.

[RickenBoogie]

Run your bass signal to the WA's input, and the cabs for the WA from spkr out. Then, run a line, (normal instrument cable) from WA's PREAMP OUT, or Effects SEND, into theLM's Effects RETURN or Poweramp IN, and connect the 2nd set of spkrs to the LM as usual. This will have the tone controls of the WA as a master for both units.

[sunbeast]

What Rick said- unfortunately the Master Volume control on the Walkabout comes before the FX return, so if you were to use it as a Slave you wouldn't be able to control the volume from it independently, whereas most amps that aren't Mesa have the Master Volume AFTER the FX loop. I think I recall reading that the LMII has its FX loop located before the EQ section on that amp, so that might complicate things as well (I could be wrong about that though).

[vin*tone]

You might also be able to use the DI out of the WA into the XLR input on the Markbass? The DI is effected by the master vol too.

[murphy]

remember the fx loop on markbass heads is parallel, so it will still be affected by markbass preamp eq controls.......unless you change it to series....by the internal jumpers

[murphy]

when i run both my heads together, i go out of the fx loop of one and just into the regular input on the other .

[Lobaw]

murphy: are you saying that you run a line out of the fx send on one Walkabout head into the instrument input of a second Walkabout head? I think I was under some impression that, if you ran a line out of the fx send on the Walkabout without closing the loop with the return, it disabled the power amp section. Hence my confusion about the whole thing.

vin*tone: I hadn't thought about running out of the DI into the MB. It makes sense, though.

The last time I tried something like this, I used a separated preamp which I ran into the fx return of another amp with good results. I don't think I'm, worried too much about dialing in the right sound on the MB. Once I get it right, I'll be able to set-up the amps each time without a problem.

Thanks, again, for the input.

[murphy]

No,no, I don't have a walkabout head, but I do run my Markbass heads together

[BassmanPaul]

The possible problem I see is that if the power amp of one head inverts the signal and the other does not then they will cancel instead of add. Identical amps should work well but those of different manufacture could be a crapshoot.