Rough copy of a tutorial on 4CM here!

[sir]

Hi Frenchfries,

Happy New Year year!

I have tried the 4CM, however, I have got too many gears so finally, I switch from 4CM to 3CM (or 7CM) as follows:

guitar -> GR20 stereo out-> Roland KC 500
GR20 guitar output -> GT8 send -> Mesa boogie amp input
GT-8 L output -> Mesa boogie FX return 1
Mesa boogie FX send 2 -> DigiTech TSR 24s -> Mesa boogie FX return 2

In this case, If I bypass the loop of my Boogie, I can use Boogie's preamp without mixing with the GT-8 preamp; as I have set the loop on my GT-8 after the preamp, so I still can use my GT-8's FXs. Seeing that my Boogie preamp got some noise, I have from time to time turn on the noise gate of my TSR 24s by switching the FX 2 button on my boogie foot controller on. If I turn the loop (FX 1) on, I can then switch on the GT-8 and bypass the preamp section of the Boogie, so now I have my GT-8 back with 4 different power amp sounding (my Road King have 4 channels) selectable.

The trouble is, if I use only one cable plugged in the Boogie, it rocks without unwanted noise, but if I once turn on the GT-8 power (with the 3CM), noise kicks in. I still can't find the "twisted pair" cables u mentioned. I wonder will this noise problem be solved by replacing my cables, or which cable should I replace actually?

Thanks!

sir

[frenchfries]

Hi Sir,
Happy new year too.
The cables to replace if necessary are those which handles an active signal. From your guitar to the first plug, you can use a coaxial model without any problem. Once the signal buffered, a "symmetrical" signal path theoretically avoids the noise... if you don't find the Planet Wave model mentioned in my posts, try to solder yourself several cables built as following:
three wires (two inside + an overall ground shielding).
First plug: solder the hot to wire 1, the ground to wire 2 and leave the shield unsoldered;
Second plug: solder the hot to wire 1 then wire 2 AND shielding to the ground.
Use some low capacitance / high quality cable (Mogami is a good example) and "Neutrik" jack plugs for sonic transparency...
Hope this helps. Good luck!

[sir]

Thanks, frenchfries! You Rock!

[DIRTEEMONKEE]

Yep they don t call him the Fries man for nothing!!!!!!!!!

[ColourSurround]

Hey FrenchFries, thanks for taking the effort to write something of such a scale.

I was reading that you should not use your amps parallel circuit in the FX loop because it can create a sort of odd mix of wet and dry signals. But somewhere else I read that it's better, though I can't remember why exactly. For use with the GT-8 how much of a difference will using series be as opposed to parallel?

Merci et Salut!

PiN

[DIRTEEMONKEE]

The serial loop is always the recommended loop....if you only have a parallel loop it is recommended to run it wide open

[ColourSurround]

What exactly does 'wide open' mean? What are some other recommended uses for the parallel port? Cheers.

PiN

[DeRigueur]

What exactly does 'wide open' mean? What are some other recommended uses for the parallel port?

If possible, the loop should be 100% 'wet'. That is, all the signal should go out the send and none should bypass the loop.

Parallel loops have a problem because a delay is introduced in the analog/digital conversions in the gt8. If this delayed signal is combined with the 'un-delayed' signal that bypassed the loop, then the 2 signals will be out of phase and sound bad.

[ColourSurround]

Brilliant, makes perfect sense. Thanks again guys.

PiN

[frenchfries]

If possible, the loop should be 100% 'wet'. That is, all the signal should go out the send and none should bypass the loop.

Parallel loops have a problem because a delay is introduced in the analog/digital conversions in the gt8. If this delayed signal is combined with the 'un-delayed' signal that bypassed the loop, then the 2 signals will be out of phase and sound bad.

+1. Thx, DeRigueur!

ColourSurround,
Parallel FX loops are probably better but require FX boxes being...
1) able to inject ONLY the FX, without any "dry" signal,
2) able to be totally desactivated when you don't use any FX.
The GT is not designed for that. It would be possible to use some extreme settings and/or some external devices in order to "mimic" a bit the two conditions above but it would reduce the potential of your modeler. No time to explain more now: I have to go to work. See you later!