VH4 Parallel Loop "Popping" Issue

[Peter Diezel]

Dear Mr. TC Electronics,

please build us an effect unit with the following specs:

1. Input load > 1 Megaohm
2. Output load < 600 ohm
3. No loaded caps on the inputs and outputs
4. A main cable that has no ground connection

Thank You very much,

Peter Diezel

 

[Peter Diezel]

Thanks Legene,

I would use the unit serial without switching.

Thanks for the kind words.

 

[i.ak]

Currently I am using Lexicon MPX G2 until I can afford Eventide Eclipse (dying for the DSP models, but...). No problems with Lexicon even though it is rather old unit. I think it was introduced in 1998 so about the same time as T.C. Electronic introduced their G-Force.

How about buying an audio switcher/looper (i.e. Digital Music Corp. / Voodoolab GCX Guitar Audio Swithcer) and putting your unit in its loop?
I am not sure does this eliminate the popping issue, but if not I think the only solution is to take a soldering iron and few resistors and so on.

 

[edgemeister]

Sorry dude, the G-Force is a pain in the behind to use witht he VH4.

Reason being is that when you have mechanical switching (dizel uses true bypass relays) to completely switch out an effect. The switching suffers from DC imbalances.

In a normal effect, if you measured the amount of DC voltage coming from the input and output jacks you'd get close to 0, as these effects have been designed for switching on and off.

The g-force on the other hand emits quite high (in effects terms) DC output from its jacks.

So what happens is, when the VH4 tries to switch the G-force out of the loop, theres an immediate switch in voltage levels in the loop, in this case a good few volts from the G-force suddenly gets shifted to 0 volts when the amp switches. This sudden change in voltage needs to escape somehow and you witness this in the form of a popping sound.

What I've also found is that if you put the g-force in the serial loop, this also annoys the hell out of the 4 channel inserts as well as obviously, these end up being affected by the g-force voltages that are emitted into the serial loop.

One way in which I've managed to solve this problem and has given me absolutley fantastic results is to use a line mixer. A guy called lyle caldwell makes one and what this does is it attaches to your serial loop, you then plug your g-force into the mixer (theres no controls on it or anything, just a box and jacks).

What this does is allow for a parrallel setup as it mixes the dry with effect signal, the same way the VH4 does, but the beauty of this is that it has a relay on it that can be triggered that can perform a 'dry kill' which essentially makes the g-force 100% serial, so you can basically switch between a serial and parrallel setup at will.

Peter, putting one of these switchable line mixers in your future amp builds might be a really cool idea! and is relatively simple

The only drawback is that the drykill on the mixer is not midi controllable it uses a relay controlled thing much like a normal amps channel selector. The way I got round this is that I have a GRX4 which can accept midi program changes and then do this switch for me. So in essence, my whole rig stays midi controlled and I have an amp that can switch between a serial and parrallel setup at will...

Hope this helps...

John