Mesa Mark IV - External Switching Problem with RJM Mini Amp Gizmo

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Joined: Fri Jul 10, 2020 1:38 pm

Mesa Mark IV - External Switching Problem with RJM Mini Amp Gizmo

Post by yillars » Fri Jul 10, 2020 1:48 pm

I have Mesa Mark IV Head version: A
I've recently bought an RJM Mini Amp Gizmo in order to switch the amp using Midi Signals.

There is a rotary switcher back of the amp (FT. SW + R1 + R2 + R3 + EX. SW) and I chose EX SW which is the correct settings to be able to use external switchers.


There are 4 cables from the Amp Gizmo;
(1. channel) (TRS) - Red -> Connected to Lead Input
(3. channel) (TRS) - Blue -> Connected to R1 Input
(5. channel) (TRS) - White -> Connected to R2 Input
(7. channel) (TRS) - Yellow -> Connected to FX Loop Input


And I put my FX Racks to the Switchable FX Loop I/O. I'm not using Normal FX Loop I/O.


When I turned off all the signals of the Amp Gizmo, I could hear a clean sound but there is no indicator on any channel which is OK.

When I turned on only 1. signal, I hear Lead sound without FX Loop which is perfect.
When I turned on only 3. signal, I hear R1 sound without FX Loop which is also perfect.
Same for 5. signal, I can hear R2 sound only.

So, when I trigger 1. signal and 7. signal which I expect to hear Lead + FX Loop, I hear only feedback. But if I turned off 1. signal which is Lead, and will let 7. signal alone then I'll hear FX Loop + Clean. Because on the backside of the amp there is a section where you can combine the FX Loop to any channel. For instance, you can combine FX + Lead or FX + R1 or FX + EMPTY which I currently set.

I already checked the manual but I couldn't find anything there.

That's what I want to have;
(1. ) -> Lead
(1. + 7. ) -> Lead + FX
(3. ) -> R1
(3. + 7. ) -> R1 + FX
(5.) -> R2
(5. + 7. ) -> R2 + FX
(7. ) -> On any channel I want to be able to turn on and off.

I hope I can find an answer and here you can find a clip;


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Re: Mesa Mark IV - External Switching Problem with RJM Mini Amp Gizmo

Post by Eevil » Fri Jul 10, 2020 1:55 pm


Can you test the switch combinations with dummy plugs or shorted cables? So you could check the correct switch combinations first without the unit :) and after you’ve figured those out would be easier to program the gizmo. IMO
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