GCX - recto channel switching problem

[skot]

Got my rig all set up this weekend, running rack wah, jc120h, gmajor, dbx gate and a 2 channel dual rectifier head, the problem I am having is my GCX wont switch the channel on my mesa consistently, if you mash the button on the ground control it will switch every 5 or 6 times the switch contacts. The lights on the mesa flicker like it wants to switch but it just stays on channel 2 most of the time. it switches the FX loop just fine, and when i plug the pedal the mesa came with it changes channels every time with no issue. I have tried every channel on the GCX and had the same problem. other than this the gcx and ground control pro are working flawlessly.

My first thought was that the contacts in the GCX were not staying closed long enough for the recto to change channels or there was something wrong in the amp, but I am posting here as well as on the mesa forums to try to get this resolved, any help will be much appreciated.

[JohnClark]

The cable being used between the GCX and the amp could be the culprit... have you tried a different cable? What cable are you using, and are you wanting to use the GCX to switch the channels and the effects loop?

Are you certain that the GCX loop being used for the channel switching is not set to Momentary?

Let us know what you find.

[skot]

I am using brand new cables, standard 1/4" and i have tried 4 different cables with the same result, I think the brand is livewire or proco i'd have to look. I tried setting the controller to momentary to see if it would work but it did not so i switched it back. atm i just want to change the channels, the fx loop switches just fine when i have it hooked up to the controller but im not using it currently

[JohnClark]

This amp requires a latching action and will use the GCX Loop Out/N.O. jack for control. Mesa sometimes recommends using speaker cable for connecting to the External Switching jacks.

On the other end of things... you said that you felt like you had to mash the button on the Ground Control Pro to get this to sometimes work. I should have asked before, but does the LED for the button on the Ground Control Pro (I am assuming you are talking about an Instant Access button) change state with every button press? Does the corresponding GCX Loop status LED change state with each button press?

[skot]

sorry, by mash i meant press repeatedly until i see the amplifier switch channels, the lights on the switch and the ground control respond normally, but the orange and red LED's on the amp head flicker when you press the button and maybe every 4th or 5th time it will actually switch the channel. I do have a few speaker cables lying around I'll give that a try.

[skot]

tested with a speaker cable, verified that both channel 7 and 8 were set to normal switch procedure and not momentary. tested in NO and NC jacks on GCX channels 7 and 8. tested with the front and back channel select jacks and still the same thing, all 3 of the LED's flicker i noticed, couldn't see the green FX loop light coming on with my room lights on. Going to try to call mesa tomorrow, the website wont let me register due to having a hotmail account.

[espboogie123]

I believe you need to have a TRS to dual mono cable to switch both channels. You would insert the TRS end in the mesa external switching/footswitch jack and the tip mono plug in loop 7 OUT/N.O. and ring mono plug in loop 8 OUT/N.O. Loops would be set to normal.

Link to cable
http://accessories.musiciansfriend.com/ ... sku=330897

[JohnClark]

We may be on to something here... I have been referring to the External Switching jacks found on the back of the amplifier. The External Switching jacks are each mono connections. There should be one for the Channel A/B and another to turn on and off the FX Loop on this particular amp. The Out/N.O. jack of a GCX loop should be connected to a single External Switching jack in order to control the labeled function.

The Footswitch jack on the front of the amplifier is in fact a TRS connection and would require an Insert Cable in order to control the switching functions, as described by espboogie123. We can assume by the trouble that the channel A/B must be on the ring connection of this jack.

So I guess the real question here is exactly which jack or jacks are you using, scot?