G-System Channel Switching Assistance

[davec69]

I can't seem to find much info on using the G-System's Channel Switching feature with my Mark IV (A). After searching TC Electronics Knowledge Base, I've determined that I can use 2 Y Cables to split into 4 mono lines, into the external switching section of the Mk IV. I'm thinking of going with:

1. Clean
2. R2
3. Lead
4. EQ

Can anyone provide further advice?

I've seen mention of problems switching two cables on at the same time.

Is there anything that I need to watch out for when setting up the relays in the G-System?

 

[Pinweaver]

The only thing which really seems to work well is using the CFX4 from Axess Electronics in between the G-system and your Mark IV. They can even provide a special cable for the mark IV.
As far as I can recall it's even mentioned in the TC Electronic knowledge base, but I could be wrong.

 

[thindave]

Don't use 2 y cables - you can damage your amp. Something to do with the MkIV switches sharing a ground (or something like that - do a search, it's been discussed a few times).

I second the CFX4 - works like a charm and no "POP" when you switch channels...

 

[davec69]

I'm familiar with the CFX4, but i'm not looking to buy another piece, if I don't need to.

I pulled the following from the TC Electronics knowledgebase:


This answer is valid for all these models: Dual and Triple Rectifier, Rectoverb, Lone Star and Lone Star Special, Solo 50, Roadking.

According to Mesa Boogie Tech dept, these units require an isolated ground connection for each of the rear panel 1/4" external switching inputs.Since Y-Split cables are sharing the ground, they cannot be used from the G-System or G-Major (which output connection is TRS) because they could cause damage to the amp switching network.

You can still use mono cables from the GMajor / G-System to any of this amp. This will obviously divide by 2 the switching possibilities since only 1 relay per output can be used.

An other solution is to use a switching device such as AXESS ELECTRONIC CFX4 or MIDI SOLUTION R8 in combination with the G-System. Note that the R8 is midi powered only and requires an adapter available at MIDI SOLUTIONS that can be powered by one of the DC 9V outs of the G-System : The G-System does NOT provide Midi power.

The Mark series (Mark 2,3 & 4, Quad, Studio Preamp, formula Preamp, V-Twin rack Preamp) can be used with Y-Split cables.

It appears that the Y-cable issue only applies to the newer models listed .

 

[thindave]

You can use the y cable, but only from 1 relay, so you can only switch between 2 channels. If you try to use 2 cables, you'll get a loud, annoying and potentially harmful "pop" in from your mkiv when you try to change to that 3rd channel.

I didn't want to get any external hw either, but I'm afraid you'll have to...

 

[6L6C]

Don't use 2 y cables - you can damage your amp. Something to do with the MkIV switches sharing a ground (or something like that - do a search, it's been discussed a few times).

I second the CFX4 - works like a charm and no "POP" when you switch channels...

ME TOO!

If you want to go a little old school try to find a Rockman Octopus on ebay like this one http://cgi.ebay.com/Rockman-MIDI-Octopus_W0QQitemZ250113307004QQihZ015QQcategoryZ22669QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
this will allow you to control all of the jacks back there so besides 1,2,3, channels, EQ, effects loop, simul-class/class A. for me there is to much of a volume difference live to be using simul-class/class A I usually just leave the loop on full time (live that is) so I would favor the CFX4.

I'm familiar with the CFX4, but i'm not looking to buy another piece, if I don't need to.

In the long run you will be better off IMHO. Just do it you will feel better once you get it.

 

[Russ]

I was about to suggest the Octopus but I figured he was already heading towards the CFX4

 

[Toneseeker]

I have recently acquired a mark 4 b and a g system. I use two y cables, one from each swithch jack on the g system. The first is attached to the R1 and R2 jacks and the second is attached to the lead and eq jacks. I have programmed presets that allow me to instantly access any channel with or without EQ. I have also assigned a button on the g system to turn the EQ on or off within each preset. Occasionally when I change between channels there is a short, loud burst of sound. I don't know why this happens only some of the time - I am still learning about this gear combination. It only seems to happen sometimes when switching while sustaining a note or chord and seems more likely to happen changing from clean to distorted sounds. I can prevent it completely by not playing briefly while switching. To me, the immense convenience of being able to switch channels with the g system outweighs any imperfections in switching. I certainly don't feel the need for extra switching gear. The latest software update for the g system (2.01) provides improvements in switching times over earlier versions - I think it might be down to 50ms but I can't remember for certain.

 

[davec69]

Well, after my first night with the G-System, I can second Toneseekers post, to the letter.

My setup is exactly as he described his, and it is working perfectly.

I unlpugged the MKIV's own footswitch, flipped the switch on the back to external switching, ran two Y cords from G-system's switch 1 & 2, into R1, R2, Lead, & EQ, put the amp in standby, and started scrolling through the relay settings until I found the desired effect. Here's my g-system setup:

CCCO = R1
CCOC = R2
COCC = Lead
OCCO = R1 w/EQ
OCOC = R2 w/EQ
OOCC = Lead w/EQ

The G-Sytsem allows you to save two relay settings with each patch. I setup a live starter bank as follows:

Patch 1 = R1
Patch 2 = R2
Patch 3 = Lead

Patch 5 = Relay Toggle (Switches between eq & no Eq for each patch)

I'm guessing that I could just move the cable from EQ jack and put it into the Simul/class A jack and use that instead of the eq, but I haven;t tried it yet.

With this setup, I can step on mod, pitch, delay and reverb or step on any of the three loops, or kick in the filter or boost section.

Tomorrow, I may get around to trying out some of the factory patches, but I wanted to get a good basic setup in the user bank, first.

BTW, I didn't have any issues with tonesucking. I went with the suggested 4 cable setup.

The problem is that there are so many areas that need attention, you really have to get your head around the signal flow, and make sure that each step in the chain is working at the correct level.

Once done, this setup sounds great.

One Important note for the 4 cable setup: The insert loop is off in all the factory presets, by default. You'll need to turn it on in each preset, or use the lock feature to lock it on all the time. If you don't do this, your signal bypasses the MKIV preamp, and goes straight to the MKIV's power amp. it took me a few minutes to figure out why my channel switching was having no effect on my tone.

 

[thindave]

That burst of sound that ts refers to is what I was told could damage the amp. I figured $150 to protect $1800 was worth it...

 

[davec69]

thindave. Did that info come from someone at Mesa Boogie? According to Mesa Boogie, there should be no problem using this setup. I will keep a close eye on the setup though, just in case.

I may still get the 150.00 Axess piece, though. Btw, what is the deal with the 50.00 MKIV cable that they have listed. Is that needed also?

 

[thindave]

You know, I can't remember where it came from - TC or Boogie - because I know I called both of them. I found it quite disturbing, so I went the Axxess route...

I'm not sure what that cable gets you - I just use 3 short, cheap 1/4" cables to switch channels...

 

[6L6C]

I may still get the 150.00 Axess piece, though. Btw, what is the deal with the 50.00 MKIV cable that they have listed. Is that needed also?

No you don’t need that cable it’s more of a convenience thing in this case. The custom cable would go from the CFX4 to the Mark IV’s jack where you would normally plug in your FU-3 footswitch. Otherwise you can still use 4 tip/ring cables audio cords are fine

 

[davec69]

I kinda like simplicity of the additional cable, but I wonder how they arrived at the 9 foot length? Why not 10ft?

Sort of off topic a liitle, but does anyone externally switch the Simul/Class A setting. I feel sort of hesitant to switch this setting too often. Maybe it's just me, but it seems like it would be hard on the amp.

 

[6L6C]

I kinda like simplicity of the additional cable, but I wonder how they arrived at the 9 foot length? Why not 10ft?

Sort of off topic a liitle, but does anyone externally switch the Simul/Class A setting. I feel sort of hesitant to switch this setting too often. Maybe it's just me, but it seems like it would be hard on the amp.

I have used the simul/class A (with the footswitch) I don’t think it’s hard on the amp, the thing is in simul-class it’s a bit of a volume jump so for me it can be a bit annoying