Mark IIC+ Slave Out - How does it work?

[LockStock]

I understand the IIC+ slave out was used by Metallica to slave the amp into a Marshall head with 6550s, and then into a Marshall 4x12 cab with Vintage 30s. Please correct me if I'm wrong.

Did they go into the front end of the Marshall head, or in through an effects return, hitting only the power tubes?

And if so, how can I use the slave out to get an instrument-level signal capable of doing either of these things. I understand the slave out is a tap off the OT, but wouldn't that be too much for an instrument cable?

I have a power scaled power amp, and I am hoping to control the volume by running the slave out into the power amp, and then using the power scaling to reduce the volume to manageable levels with the Mesa OT fully engaged.

 

[psychodave]

They prob went into en effects loop of a Marshall (prob a mod).

As for Slaving, I slave my IV into my III all the time. I just come out of the IV with a normal guitar cable and into the return of the III's loop. I adjust the level on the IV.

I have also gone from the slave if the IV into a Marshall poweramp using the same procedure. 8)

 

[LockStock]

Thanks - do you have your Mark IV attached to a speaker or load as well, or can you really turn your Mark series all the way up and just slave it by an instrument cable into the power section of another amp?

 

[devilrob1979]

It has to have a load. You can use a dummy load but something's gotta be there for the output transformer or you will blow your amp up.

 

[LockStock]

That's what I thought. Thanks! So the solution to a too-loud full-bore Mark series is simply to put the output into a loadbox, line out from the slave into a solid state power amp, and turn the volume to taste? You get all the tone, and get to retain your hearing?