Effects loop / Pre-amp question

Gresh · #1 10-03-2002, 10:45 AM

Not that I would do this, but just curious.

Would this work:
Guitar into AB switch. One signal routed to Marshall TSL, other to POD Pro. POD Pro output into Marshall effects return.

Seems simple and logical to me, but I've never tried it. Looking at getting a Marshall head to play with, but would still like to use some of the tones in my POD Pro as well.

Rodney James · #2 10-03-2002, 02:41 PM

The Effects return on the Marshall is same as a Power amp in, with the Marshall preamp being by passed when used. If you run the Pod into the return, even though you have a signal run into the Marshalls main input, the pre amp would be inactive.

Picture A head or combo amp having a Pre-Amp and power Amp, the effects loop is a break in the signal path between the two. Effects Send is pre-Amp out, Effects return is power Amp in...

Doing the A/B thing, you would of course have to run the Pod into it's own amp if you want to A/B the Marshall Pre-amp for tones also.

Gresh · #3 10-03-2002, 02:55 PM

OK, I get it. I didn't realize that by using the effects return jack it automatically bypassed the pre-amp section, but that does make sense.

MidnightFlamed · #4 10-03-2002, 03:33 PM

I'm guessing the TSL doesn't have a footswitch-controllable effects loop?

Two hands31 · #5 10-03-2002, 03:34 PM

Ok, here's what you'd need to do. You'd need to put a y-cable of some sort to blend the POD Pro with the signal coming from the FX out of the Marshall. It would be sorta like this:

http://www.geocities.com/two_hands31/PodMarshallRig.jpg

mike777 · #6 10-04-2002, 02:42 PM

Remember that even though you'd be bypassing the preamp, you need to make sure that the FX mix control is set to "10". The reason I say this is because that circuit is designed to by series and parallel. It's a parallel circuit from 1-9 and series at "10". I'm just thinking that you may get some extra residual noise (hiss or whatever may naturally occur even if no signal is passing through it) if you have the FX mix set to anything less than "10" let alone the volume of the signal coming in to the return jack will be at a lower volume.

This brings up another possibility: If you have an ABY switch where you can run both signals simultaneously-you could experiment by BLENDING both sounds usinge the FX mix control as a mono mix control.

Since the FX loop is footswitchable-you can take it out completely when you want to use the AMP tones only by just taking out the FX loop which will avoid any residual noise from the POD.

So now your capabilities and options just tripled. Life is good. God Bless America and British amplification! I never thought about this and this is very interesting now that you've made me think about this. I'm so glad I'm off next week!

Mike 777 Haug