Mark IV effects loop preamp trick

[Tuna141]

I just wanted to share a cool Mark IV effects loop feature that I discovered:

Since the loop is switchable, you can switch between the Mark IV preamp section and another preamp section if you have something that can split the input signal.

For instance, I can plug my guitar into my GCX unit, which splits the signal and feed one output to the Mark IV's input, and the other into my rack preamp's input. Then feed the rack preamp's output into the Mark IV's effect return jack. The result is that I can use the Loop button of the Mark IV footswitch to toggle between the Mark IV and my rack preamp being powered by the IV's power section. The Graphic EQ is functional in both modes. Talk about versatility. I'm going to mess around with this set-up more this weekend.

In amps with non-switchable loops this type of configuration isn't possible.

Just thought I'd share...

 

[zx81]

My amp has a non-switchable loop, so I used the old a/b box trick. The a/b box is connected to the preamp and the amp. The pre-amp signal goes into the amp's fx-return. A dummy plug goes into the amp's fx-send so that the Fx-level can be used to set the level between the two signals.

 

[PRSKILLER]

So it this to say if I wanted to, I can use a Marshall JMP-1 preamp with the Mark IV? If so that would be cool to have the best of both worlds.

 

[zx81]

It works for me, has worked for others. But why Marshall??? :shock:

 

[t0aj15]

I just wanted to share a cool Mark IV effects loop feature that I discovered:

Since the loop is switchable, you can switch between the Mark IV preamp section and another preamp section if you have something that can split the input signal.

For instance, I can plug my guitar into my GCX unit, which splits the signal and feed one output to the Mark IV's input, and the other into my rack preamp's input. Then feed the rack preamp's output into the Mark IV's effect return jack. The result is that I can use the Loop button of the Mark IV footswitch to toggle between the Mark IV and my rack preamp being powered by the IV's power section. The Graphic EQ is functional in both modes. Talk about versatility. I'm going to mess around with this set-up more this weekend.

In amps with non-switchable loops this type of configuration isn't possible.

Just thought I'd share...

I use the same basic idea with my Mark IV and TriAxis setup, but I have carried it a little further. The preamp out signals from both preamps feed back into the GCX which then selects and sends them to A. the Mark IV power amp to power a center channel dry speaker and to B. all the efx which are also switched in and out of the chain by the GCX and then on to a Boogie 50/50 stereo power amp which drives two Boogie Thiele 1-12" cabs which carry the wet signals. The whole thing is then controlled with a Ground Control Pro midi footcontroller. It makes for a great sounding W/D/W setup.

 

[PRSKILLER]

It works for me, has worked for others. But why Marshall??? :shock:

I want to have both brands at hand, ready to kick in at anytime. :lol:

 

[jargapix]

Mine was made in 2003. I don't believe it's switchable...anybody know.

JA

 

[Tuna141]

zx81 Posted: Fri Feb 24, 2006 9:33 am Post subject: there's more... My amp has a non-switchable loop, so I used the old a/b box trick. The a/b box is connected to the preamp and the amp. The pre-amp signal goes into the amp's fx-return. A dummy plug goes into the amp's fx-send so that the Fx-level can be used to set the level between the two signals.

ZX81 - I'm still not exactly sure how you hook up your non-switching loop. Will you explain in a little detail (especially about the "dummy plug")?

I presently use the Mark IIC's effect return (power section) to power my rack preamps (Triaxis & Egnater IE-4), but didn't think I'd be able to switch between the preamps and Mark IIC's preamp section with the Mark IIC. I tried doing it on the Mark IV because the loop was switchable.

If it can be done with the Mark IIC, then I'm defintiely going that route :lol: