There's one downside to 4cm connection
Balancing levels is a major PITA
It helps if you can record it or have some kind of output indicator
in a worst case scenario go straight into a recorder/indicator from the preamp/G-system's outs,
it may sound like crap, but it gets results
Any old tapedeck with VU meters could do the job, even without tape
-It goes without saying that you make a patch in the G-system with the loop enabled,
where you already select where the preamp is gonna be in the signalchain
and which FX are gonna be pre-or post preamp-
First up, Post-Preamp Signal
-Plug your guitar into you amp without any other devices with the levels set at the desired volume
Listen to/look at the levels
Next
Keep your guitar into the preamp input
Plug the preamp out into the G system loop return
Plug the G-system outs into the RM100's serial return (or recorder/indicator)
keep all FX off and adjust G-system's loop return level if needed
(Or RM's Preamp signal if it's too hot going in)
Listen/Look/Compare
Then
Switch all Post-preamp FX on/off one at a time (or use a bypass function), but keep the FX at 0% wet,
so your FX are passing thru an unaffected signal
Listen/look/Compare per FX-block
Adjust any differences
Post FX could become a lot easier if you use only the parallel (100% wet, 0% Dry) loop/FX
but once you want to use post-EQ/Compression/Flanger/Etc,
You're again wrestling with levels
It's much easier afterwards only having to adjust Dry signal to zero when using parallel
and this way, you can always swap FX blocks in the signalchain around the preamp without any problems
So when this is done you can keep the G system in the serial loop
(since those levels wil now be 'calibrated')
Next up
Pre-Preamp Signal
Plug into the G-system, put the Preamp in the G-system Loop
Listen/Look/Compare
Then repeat what you did with the post loop -exception being you first have to adjust (if needed) the G-system's Loop-Send level-
Switch all Post-preamp FX on/off one at a time (or use a bypass function), but keep the FX at 0% wet
Listen/look/Compare per FX-block
Adjust any differences
Save patches between adjusting respectively under name "Unity Gain"
Save it to the last available presets on the G-system and -if possible- make a midi dump from it
(or write the settings down)
this way you'll always have a blank slate to start from
-
Don't know if this helps, or if I'm even close to giving you a correct way of doing things, had to type it all by memory and there's been a lot of time and beer since I had to set up my Lexicon G2
Surely there are people around who can simplify, correct or dismiss any suggestions I've made here if needed