GR-55- Creating an external effects loop for the modeling tones

Started by justinmorell, April 30, 2011, 11:26:45 PM

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justinmorell

Hi all,

I'm new here, and just got my GR-55 about a week ago.  So far, I like it quite a lot, but like a lot of other users around here, I'm pretty disappointed that there's no external effects loop.  I know others have described how to insert external effects in a "loop" that essentially consists of running cables from the magnetic "Normal Pickups" output of the guitar, to the effects, and back up to the GK, but I'm more interested in getting external effects patched into the modeling sounds before all of those time-based effects built into the GR-55.  I came up with a method that seems to work, and posted it on my blog page, but here's the basic info:

Master Settings

First you'll want to go to System Settings-Other and assign the Guitar Out Source to Modeling. This will send the dry Modeling signal to the Guitar Out jack at all times. It is recommended that you do this first, since the effects loop wiring can create a feedback loop if this jack is set to receive the Normal Pickup signal. You can also change this setting on a patch by patch basis in the Master-Guitar Out settings, just don't forget to undo the wiring setup described below before you change to any patch using the normal guitar through the guitar out jack.

The Cabling

The next step is to run a cable from the Guitar Out jack to any external effects you want to use, and then run a cable from the last effect up to your GK pickup, and plug it into the guitar pickup input on the GK. Essentially you're tricking the GR-55 into thinking that its own modeling signal is coming from your regular guitar pickups. Keep in mind that any effects you have patched in here will be heard in the signal chain before the rest of the internal GR-55 effects. Your special wiring is done.

Set Up Your Patch Volumes


The final step is done in the main Tone edit page. You'll want to turn your modeling signal on and set it to about 100 or whatever setting you think sounds best for your setup. This will be the volume that is sent to the Guitar Out jack. You also need to turn off the little Patch Switch virtual button on the left side of the model tone name. This mutes the modeling signal to the main mono/stereo mix outputs. Finally, you need to turn on the Normal Pickup signal and set it to whatever volume you like. Remember that the GR-55 thinks you're sending it your regular guitar pickup to the Normal Guitar input, but in fact the signal it's hearing has been rerouted from the modeling tone and all of your external effects. It's up to you whether or not to include any PCM sounds in addition, since these will still function as usual.

I'm thinking that using a US-20 with the hardware mod some others have described in other threads (adding the guitar in/out from the 13-pin cable) might make this wiring more efficient.  However, I don't yet own a US-20, so I can't try it out.  Any ideas?  You can check out the more detailed version of this setup on my blog http://justinmorell.com/blog/?p=322 but the basic info is really all in this post.  Of course, you won't be able to use your regular pickups through the GR-55 with this wiring, and you'll have to send the modeling signal out the mix outputs to your amp/PA, both of which are a bit limiting.

I've learned a ton about this unit from other members on this site, so I'd really like to thank all of you for the help!
justin

GR-55, VG-99

gumtown

Justin - I see in your sig, you use a GT-8.
Have you tried this?

GK > GR-55
GR-55 guitar out (normal and/or modeled) > GT-8 input
GR-55 L/Mono Output > GT-8 Loop Return (return level @ 35)
GT-8 L/Mono out > Amp

Have the S/R Loop at the end of the GT-8 signal chain.

And maybe try
GT-8 midi-out > GR-55 midi-in
GT-8 midi-in > GR-55 midi-out
with the GT-8 and GR-55 EXP pedal cc# send disabled.
This will allow both units to track the same patch changes together from either unit or the GK S1/S2 buttons.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

justinmorell

Thanks Gumtown.  I actually haven't tried that signal routing setup, and here's why:  I always run the magnetic guitar signal directly out of my guitar and into my other effects/amp, since I don't like the way the GR units color the sound of the magnetic pickups (I did this with my GR-20 and my GR-50 too).  I also have several other effect pedals that I like, and I use those in the effects loop of the GT-8, so that means I can't use that effects loop for anything else.  Finally, my favorite amp is an old Rivera-modified Fender Vibrolux with two separate channels, one of which i LOVE for my regular usual guitar sound but that is way too mid-rangy for any of the more traditional modeled sounds.  Therefore I need to run the modeled sounds (and the synth sounds for that matter) into a separate channel in the amp for a flatter EQ curve.  It doesn't bother me too much that the modeled guitars and the synth sounds share the same channel since I tend to set that channel with a fairly flat response that works well for both.

I think what I was hoping for with the GR-55, other than an updated PCM sound library--and I do really love the fact that I can still get my favorite classic GR-type sounds from the GR-55 plus a whole bunch of new stuff--was a set of versatile traditional guitar models that I could call up on a gig for that one song that just needs a Strat or Tele or whatever.  The fact that I couldn't insert a distortion pedal on the modeling tones before the rest of the effects was a big disappointment, since the internal overdrives are a little, uh, lackluster at times.  The method I came up with at least allows for the insert to occur on the modeling tones, even though it precludes one from mixing in the magnetic pickup sound . . . and of course still means that I have to carry around a ton of other effects and cables.

What I'd really like is to set up a break-out box with a "guitar in"--as has been described in other threads--so that I don't have to run a cable back up to the physical GK pickup on the guitar itself.  I'm wondering, since the GK-3 does have an impedance step-up (or step-down) for the guitar input, does this need to be compensated for when using the above described loop setup?  I mean, do you think it might sound better if there were a way to bypass that impedance step?  Is it possible to bypass it with some hardware mod, perhaps by putting the jack on the unit itself and jumping over it?  Or is the impedance change compensated for somewhere in the software implementation of the GR-55 much later on?

I must say that with the modeled tones, I'm not that sensitive to whatever tone loss might be happening by rerouting the signal through the GK guitar input, perhaps because the modeled tones are a kind of "already processed" sound to begin with.  But if I could gain a little extra transparency, I suspect it might be noticeable in some situations.
justin

GR-55, VG-99

paults

Wiring the "Guitar Out" signal directly to the Pin 7 wire for the 13 pin connector inside the GR-55 would do work, as long as you will never use the regular guitar signal, or ever send signal out of the "Guitar Out" jack.  If you want to keep those options open, add a switching jack that will bypass the jumper, and/or a pin 7 "pickup or internal source" switch.



justinmorell

Quote from: paults on May 01, 2011, 09:34:01 AM
Wiring the "Guitar Out" signal directly to the Pin 7 wire for the 13 pin connector inside the GR-55 would do work, as long as you will never use the regular guitar signal, or ever send signal out of the "Guitar Out" jack.  If you want to keep those options open, add a switching jack that will bypass the jumper, and/or a pin 7 "pickup or internal source" switch.

This would work to refeed the modeled tone back into the magnetic pickup input, but would defeat the purpose since it eliminates the ability to insert an external effect between the modeled tone and the internal effect chain--if I understand you correctly.

The more I think about it, the more it seems that the only way is to put a jack wired to pin 7, and include the appropriate buffer, if I want to avoid the wiring tangle back up to the guitar-mounted GK.
justin

GR-55, VG-99

paults

Have you listened to your idea? Is a buffer needed for the Guitar Out signal to Pin 7?

I'll rephrase my wiring suggestion:

Wire the "Guitar Out" signal to a send/return 1/4" jack.  The return is directly wired to the to the Pin 7 wire for the 13 pin connector inside the GR-55.  You can use a jack that also has switching terminals, to make the GR-55 behave normally when no cable is plugged in.  Or, you could have it connect directly to pin 7 when no cable is selected.



justinmorell

Quote from: paults on May 01, 2011, 02:15:09 PM
Have you listened to your idea?

Wow!  OK, I guess I must have offended you.  I did not mean to.  As I said in my earlier post, perhaps I misunderstood your suggestion.  I have in fact "listened to my idea."


Quote from: paults on May 01, 2011, 02:15:09 PMIs a buffer needed for the Guitar Out signal to Pin 7?

Perhaps I just don't understand how the guitar input on the GK-3 works, but from what I've read elsewhere in this forum (here for example: https://www.vguitarforums.com/smf/index.php?topic=3644.msg25551#msg25551), there is a built in buffer that lowers the impedance on the magnetic pickup.  It would seem to follow that simply inserting a jumper to pin 7 and sending a guitar-level signal (i.e. the signal I'm feeding out of the Guitar Out jack with the modeling tone) to the inside of the 13-pin jack on the GR-55 would thus require a similar buffer to compensate for the fact that the aforementioned "loop return" will no longer be fed directly into the GK-3.  Obviously, according to your post, I must be wrong.  I'm not an expert in electronics.  My apologies.


Quote from: paults on May 01, 2011, 02:15:09 PMI'll rephrase my wiring suggestion:

Wire the "Guitar Out" signal to a send/return 1/4" jack.  The return is directly wired to the to the Pin 7 wire for the 13 pin connector inside the GR-55.  You can use a jack that also has switching terminals, to make the GR-55 behave normally when no cable is plugged in.  Or, you could have it connect directly to pin 7 when no cable is selected.

What I don't understand here, and in your previous post, is this: What would be the purpose of having the "Guitar Out" signal connected to pin 7 at any time, since this simply sends a signal right back to where it started?  Why wouldn't one simply turn on the modeling signal and send it as usual to the mix outputs?   Perhaps there is a reason, but I honestly don't know what it would be.

Anyhow, the point of my original post was to share an idea I had that for me seemed quite useful, and I thought it might be useful for others.  I did not mean to cause trouble.  However, I hardly think I deserved such a snide response.
justin

GR-55, VG-99

gumtown

Justin, i can follow your idea and line of thinking, and i think it is an absolutely brilliant 'out of the square' way of achieving the most from your gear.
I have been thinking of modifying my GR-55, by drilling in an insert jack (or two - one out and one return) next to the GK socket, and breaking into the normal pickup of the GK wiring, but of course i am natuarally a little apprehensive on doing that.
That would allow either the normal PU via the breakout jack or the modeled tone and/or the normal PU via the guitar out jack, to pass to an external effects processor, and then be re-inserted back into the GR-55.
That will do away with the extra cabling to the GK pickup.

I could also add one more jack socket connected to one of the GK hex signal inputs, to use the GR-55 with a non-GK source as a monophonic modeling/synth unit.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

ddlooping

Diaz Guitars (work in progress)

ddlooping

Diaz Guitars (work in progress)

Elantric

#10
As a reference: The Normal Guitar signal flow goes like this:

STEP#1: Normal Guitar pickups on your guitar will feed a guitar mounted GK-13 Preamp driver board (Roland, Ghost, RMC) .

STEP#2: Inside the GK-13 Preamp driver board is an op amp buffer that performs a Hi Z to Lo Z impedance conversion, whose output feeds GK13 cable pin #7. 

STEP#3: The 13 pin GK cable from your guitar feeds the GK IN" jack, and pin #7 from your 13 pin cable has the "low Z" Normal Guitar signal.

STEP#4: Due to the low impedance of the internal "normal guitar signal path" inside the 13 pin cable (as a result of Step # 2) If you modify the signal downstream to create an FX Insert point, you must use a signal buffer between your Guitar and the Pin#7 signal connection.

Using an ordinary Boss pedal works as a HiZ to Low Z signal buffer for this function ( I use a Boss TU-3 Tuner), but many other pedals work too - Ibanez Tube Screamers, Boss  CS-3 Compressor, DS-1 distortion, etc, as used in my US-20 "magic Box" mod. If you use FX which feature "True Bypass" - you will need to add a Hi Z to Low Z buffer circuit to feed the Normal PU path on the target processor (VG-99 / GR-55) 



Gastric

There's a TON of room in the chassis to splice some jacks into the 13 pin wiring harness (what I would do) or PCBs inside, somewhere I posted a pic showing some jacks stacked up next to the GK jack.  In my opinion that would be preferable as opposed to running another cable to your GK controller on your guitar. And if you used switched jacks you could use them as inserts - don't plug anything in and everything works 100% as factory, they only enable when you physically plug a cable into the jack. Gives you a lot of flexibility without risking screwing stuff up. I was hoping I'd toss the idea out and some electronics genius would take it and finish up a nice step-by-step for us detailing the proper cables to splice into, etc. :)

gumtown

Quote from: Gastric on May 01, 2011, 07:17:59 PM
There's a TON of room in the chassis to splice some jacks into the 13 pin wiring harness (what I would do) or PCBs inside, somewhere I posted a pic showing some jacks stacked up next to the GK jack.  In my opinion that would be preferable as opposed to running another cable to your GK controller on your guitar. And if you used switched jacks you could use them as inserts - don't plug anything in and everything works 100% as factory, they only enable when you physically plug a cable into the jack. Gives you a lot of flexibility without risking screwing stuff up. I was hoping I'd toss the idea out and some electronics genius would take it and finish up a nice step-by-step for us detailing the proper cables to splice into, etc. :)

OK i think i will step up to that challenge, i will probably do 2 plugs and a switch (if they will fit) like this,
1) Socket for normal PU out
2) Socket for Normal PU return (insert switched jack, a plug in here will break the circuit)
3) Switch to connect normal PU to one of the hex GK inputs,
    so i can plug in a normal non-GK guitar/bass/mic and make use of monophonic cosm modeling and pcm tones.

I will try it first un-buffered, and if there is an issue with impedance mismatch, i will install a home built op-amp buffer (copied from the GK).
Will also take step by step photos and provide a detailed description on how to do it.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

Elantric

GumTown, I suggest perform a reversible modification.

Swap out the plastic USB thumbdrive door with a new metal plate which houses 1/4" FX Loop jacks , remote S1 & S2 switching and a USB jack for thumbdrive.

Avoid drilling holes in the GR-55 , which only serves to lower the resale value.

justinmorell

Quote from: Elantric on May 01, 2011, 06:53:46 PM
STEP#4: Due to the low impedance of the internal "normal guitar signal path" inside the 13 pin cable (as a result of Step # 2) If you modify the signal downstream to create an FX Insert point, you must use a signal buffer between your Guitar and the Pin#7 signal connection.
Using an ordinary Boss pedal works as a HiZ to Low Z signal buffer for this function ( I use a Boss TU-3 Tuner), but many other pedals work too - Ibanez Tube Screamers, Boss  CS-3 Compressor, DS-1 distortion, etc, as used in my US-20 "magic Box" mod. If you use FX which feature "True Bypass" - you will need to add a Hi Z to Low Z buffer circuit to feed the Normal PU path on the target processor (VG-99 / GR-55)

Ok, this is great info, thanks.  Let me just make sure I understand, if you don't mind.  A pedal such as the Tube Screamer will output a Low Z signal, right?  And this means that once your guitar hits the first pedal in a chain of effects, you are essentially running Low Z from that point on, all the way into the amp?  I never knew that, and I think this is what had confused me above.  It seems so counter-intuitive that an effect pedal would not convert back to Hi-Z on the way out, considering that one would expect to hit the amplifier preamp with the same impedance of the regular guitar output.

With this in mind, assuming I would never want to plug the guitar directly into the pin-7 "return" modification, and that I would ALWAYS be using the output of the GR-55 "Guitar Out", it shouldn't matter that there's no buffer going to pin 7, since that Guitar Out signal will have already been converted to Low-Z.  Is that correct?  And if so, does it hurt anything to install the buffer and then run the Low-Z signal into that jack?  Presumably not, since running the guitar through a series of stomp boxes (each of which would add its own impedance step to the chain) seems to work just fine--except for the bit of tone-drain that always occurs with multiple stomp boxes.

Am I getting this? Sorry, guys, for being a bit dense with this stuff.

Quote from: Gastric on May 01, 2011, 07:17:59 PM
I was hoping I'd toss the idea out and some electronics genius would take it and finish up a nice step-by-step for us detailing the proper cables to splice into, etc. :)

I like this idea!  :D  I did see the pic with the internal jacks in that other thread.  I'm trying to work up the nerve to do it, but would like to have a clearer idea of exactly what I'd be doing once I start drilling and soldering.

Thanks guys!
justin

GR-55, VG-99

Elantric

All you state below is precisely correct.
QuoteOk, this is great info, thanks.  Let me just make sure I understand, if you don't mind.  A pedal such as the Tube Screamer will output a Low Z signal, right?  And this means that once your guitar hits the first pedal in a chain of effects, you are essentially running Low Z from that point on, all the way into the amp?  I never knew that, and I think this is what had confused me above.  It seems so counter-intuitive that an effect pedal would not convert back to Hi-Z on the way out, considering that one would expect to hit the amplifier preamp with the same impedance of the regular guitar output.

With this in mind, assuming I would never want to plug the guitar directly into the pin-7 "return" modification, and that I would ALWAYS be using the output of the GR-55 "Guitar Out", it shouldn't matter that there's no buffer going to pin 7, since that Guitar Out signal will have already been converted to Low-Z.  Is that correct?  And if so, does it hurt anything to install the buffer and then run the Low-Z signal into that jack?  Presumably not, since running the guitar through a series of stomp boxes (each of which would add its own impedance step to the chain) seems to work just fine--except for the bit of tone-drain that always occurs with multiple stomp boxes.

gumtown

Quote from: Elantric on May 01, 2011, 07:44:01 PM
GumTown, I suggest perform a reversible modification.

Swap out the plastic USB thumbdrive door with a new metal plate which houses 1/4" FX Loop jacks , remote S1 & S2 switching and a USB jack for thumbdrive.

Avoid drilling holes in the GR-55 , which only serves to lower the resale value.

Now i do like that idea !!  ;D
That will give me the opportunity to test the USB plug, because i am having a bit of grief with the File Player not reading the USB pen drive most of the time, and having to wiggle the stick and restart the GR-55 for it to read the songs.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

samandlyn

Quote from: justinmorell on May 01, 2011, 07:55:39 AM
Thanks Gumtown.  I actually haven't tried that signal routing setup, and here's why:  I always run the magnetic guitar signal directly out of my guitar and into my other effects/amp, since I don't like the way the GR units color the sound of the magnetic pickups (I did this with my GR-20 and my GR-50 too).  I also have several other effect pedals that I like, and I use those in the effects loop of the GT-8, so that means I can't use that effects loop for anything else.  Finally, my favorite amp is an old Rivera-modified Fender Vibrolux with two separate channels, one of which i LOVE for my regular usual guitar sound but that is way too mid-rangy for any of the more traditional modeled sounds.  Therefore I need to run the modeled sounds (and the synth sounds for that matter) into a separate channel in the amp for a flatter EQ curve.  It doesn't bother me too much that the modeled guitars and the synth sounds share the same channel since I tend to set that channel with a fairly flat response that works well for both.

I think what I was hoping for with the GR-55, other than an updated PCM sound library--and I do really love the fact that I can still get my favorite classic GR-type sounds from the GR-55 plus a whole bunch of new stuff--was a set of versatile traditional guitar models that I could call up on a gig for that one song that just needs a Strat or Tele or whatever.  The fact that I couldn't insert a distortion pedal on the modeling tones before the rest of the effects was a big disappointment, since the internal overdrives are a little, uh, lackluster at times.  The method I came up with at least allows for the insert to occur on the modeling tones, even though it precludes one from mixing in the magnetic pickup sound . . . and of course still means that I have to carry around a ton of other effects and cables.

What I'd really like is to set up a break-out box with a "guitar in"--as has been described in other threads--so that I don't have to run a cable back up to the physical GK pickup on the guitar itself.  I'm wondering, since the GK-3 does have an impedance step-up (or step-down) for the guitar input, does this need to be compensated for when using the above described loop setup?  I mean, do you think it might sound better if there were a way to bypass that impedance step?  Is it possible to bypass it with some hardware mod, perhaps by putting the jack on the unit itself and jumping over it?  Or is the impedance change compensated for somewhere in the software implementation of the GR-55 much later on?

I must say that with the modeled tones, I'm not that sensitive to whatever tone loss might be happening by rerouting the signal through the GK guitar input, perhaps because the modeled tones are a kind of "already processed" sound to begin with.  But if I could gain a little extra transparency, I suspect it might be noticeable in some situations.
Hi Justin,

I am getting my GR-55 any day now, and your comments have been great food for thought, and I have been mulling over the implications for hours now.
It sounds to me like you have certain effects pedals that you don't want to change in your set-up, although bringing a new unit like the GR-55 to your repertoire can also open up new possibilities.

In theory, if you could free up the effects loop in your GT-8 for a bit,  what would you think of the  the following setup?
Magnetic pickup of guitar > input GT-8
Effects send of GT-8> 1/4" input jack of GK-3
Guitar out of GR-55 > effects return of GT-8
mono L output of GT-8> 1st channel of your amp
mono L ouput of GR-55 > 2nd channel of your amp ( the flat response one)  or for others into PA

Now when you want PCM synth or modelled sounds from your GR-55 you activate the S/R loop on GT-8 and have these sounds added to the GT-8 chain?

Or am I just confused???


a2dconverter

#18
Hey Guys...here's what I've done to modify my US-20 Clone that allows a SEND/ RETURN before the GR-55 as well as allowing me to connect a Normal Guitar to the GR-55 in the absence of a 1/4" Guitar in on the GR-55...

GUITAR OUT  - allows you to SEND the MAG signal from your Normal pickups using your 1/4" guitar cable to EXT FX
GUITAR IN    - allows you to RETURN the output of your EXT FX to the GR-55  OR  to connect your normal guitar to the GR-55 and use the GR-55 FX

When I'm using the GK Pickup, and there is nothing plugged into either the GTR IN or the GTR OUT jacks, the signal is Normalized and the MAG signal is continuous from the US-20 GK IN to the GK A and B OUTS as normal.

After that long explanation, I rarely use the GTR IN/OUT... I installed those Jacks on the off chance that I want to use the GR-55 FX with my non-GK Guitars in the future.

What I really do use is a US-20 Mod that breaks out the GK volume and the S1/S2 switches.

This is useful for me as all of my Guitars have Graphtech Piezo saddles and Hexpander drivers installed and I didn't want to modify my guitars with extra holes, so, the S1/S2 swiches and GK volume control are not on my guitars. The S1/S2 and GK Volume break-out of the US-20, to two external footswitches and an EV-5, allows foot control of those functions. The small RED toggle switch allows the use of a standard GK Pickup for GK Volume or the external EV-5 for GK Volume (Since my guitars do not have a GK Volume...  the switch would allow GK volume with a GK-3 loaded guitar in the future)







Because of Roland's oversight to allow the internal GR-55 FX to be processed through the GR-55 GUITAR OUT Jack, I use this configuration...

GUITAR OUT from GR-55 through an external effects board to a MESA tube amp. This sounds the best as I have invested so much in my Guitar outboard gear and can use the GR-55 alternate tunings to my existing Guitar setup. The GR-55 synth sounds go to the PA via direct box.



Hopefully this gives you guys some ideas...

seeya

Joe
Guitar Synths/ Controllers
GR-1
GI-20
GR-55
Custom US-20 w/ Breakout for GK Volume and S1/S2
Inline RMC GR-55 Sub-Filter
2 x Ibanez Roadstar II with Graphtech Floyd Rose Piezo Bridge and Hexpander Driver
PRS Santana w/ Graphtech Piezo Saddles and Hexpander Driver
etc...

ddlooping

Very nice job, Joe, and thanks for sharing the info. :)
Diaz Guitars (work in progress)

justinmorell

Quote from: samandlyn on May 02, 2011, 05:29:15 AM
In theory, if you could free up the effects loop in your GT-8 for a bit,  what would you think of the  the following setup?
Magnetic pickup of guitar > input GT-8
Effects send of GT-8> 1/4" input jack of GK-3
Guitar out of GR-55 > effects return of GT-8
mono L output of GT-8> 1st channel of your amp
mono L ouput of GR-55 > 2nd channel of your amp ( the flat response one)  or for others into PA

Now when you want PCM synth or modelled sounds from your GR-55 you activate the S/R loop on GT-8 and have these sounds added to the GT-8 chain?

If I understand correctly, it looks like the advantages to your wiring above are: 1) that you're hitting the GT-8 with the direct guitar signal as opposed to the guitar signal that comes from the GR-55.  I'm not sure how much of an advantage this is.  Perhaps it might sound a little better if you're using the GT-8 overdrives and getting a little bit purer tone to drive them; and 2) you can send the magnetic pickup signal and the modeling signal to different points in the GT-8 signal chain depending upon where you place the send/return in the GT-8 patch chain.  For example, with one patch on the GT-8 (or using it in manual mode, which is often really handy) you could have the magnetic pickup run through a compressor and distortion, then turn the loop on and have the modeling tone--fed out through the GR-55 "Guitar Out" jack--hit the GT-8 after the distortion and compressor.  I could definitely see the advantage here.

If you aren't planning to do something like either of these options, you might have a simpler time just running the Guitar Out from the GR-55 to the GT-8 in.  In your description above, you mentioned being able to add the PCM sounds to the GT-8 chain.  This won't work in your setup, since the Guitar Out path will only output either the magnetic pickup signal, or the modeling signal, or both.  And the GR-55 Guitar Out will always send a dry signal out the Guitar Out--magnetic or modeling--so you won't have the advantage of using the GR-55 effects on your magnetic signal you're feeding back into the GT-8.  In other words, you aren't getting any additional effects processing on the guitar by running it this way.

Let me know if I'm not understanding your concept here.

FWIW, my setup goes something like this:

Magnetic pickup (direct from the guitar jack) > GT-8 > GT-8 send > TC-electronic distortion > TC phaser > Ernie Ball volume pedal > GT-8 return > Boomerang III looper Left Input > Boomerang Left output > amp channel 1

This gives me a lot of flexibility with the guitar signal, and keeps it isolated to its own amp channel.  Then, on a separate path:

GR-55 Left mix output (the mono mix) > Boomerang III looper Right input > Boomerang Right output > amp channel 2 (the flat response)

This gives me a channel for PCM and/or modeling tones, and any effects I need on either of these have to come from the internal GR-55 chain.  The Boomerang runs true stereo, so I can loop anything and yet keep the signals separate to the amp channels!  Now, with lots of extra cabling, I can add:

GR-55 guitar out (modeling signal only) > other effects pedals, maybe ME50 or GT-3 or trusty old ProCo Rat > GK-3 magnetic pickup input

This gives me whatever pre-time-based colors I need on the modeling signal.  To control this loop, I have two assigns setup on the GR-55 as follows:

Assign 1: expression switch (or ctrl switch)
MIN: modeling tone on
MAX: modeling tone off
set to toggle

Assign 2: SAME CONTROLLER AS ABOVE
MIN: Magnetic pickup volume = 0
MAX: Magnetic pickup volume = 50 (or so)
set to toggle

This means that when I step on the exp switch, I turn on the loop that sends the modeling signal to the external effects and back up to the GK-3.  This really helps me make the most of the modeling tones.

So far, other than the cabling mess, this works out great.
justin

GR-55, VG-99

paults

Whoops!   

Justin - Apologies to you for my question coming across that way, and also anyone else who read it as offensive.  That's wasn't at all what I was trying to do. Typed conversational English doesn't always translate well.

I was curious to find out if you had listened to the results of your idea by experimenting with a temporary substitute for a break-in box.

I was asking, because the 55's Output jack has a different impedance than a regular guitar, so the GK buffer (or similar) may not be needed to send the COSM sound of the GR-55's Guitar Out jack back into the 55.  If a buffer wasn't needed, it would be simpler to do.

I'll go back up and read the rest of the thread now...  :-[


ddlooping

Diaz Guitars (work in progress)

justinmorell

Quote from: paults on May 02, 2011, 06:11:22 PM
Whoops!   

Justin - Apologies to you for my question coming across that way, and also anyone else who read it as offensive.  That's wasn't at all what I was trying to do. Typed conversational English doesn't always translate well.

I was curious to find out if you had listened to the results of your idea by experimenting with a temporary substitute for a break-in box.

I was asking, because the 55's Output jack has a different impedance than a regular guitar, so the GK buffer (or similar) may not be needed to send the COSM sound of the GR-55's Guitar Out jack back into the 55.  If a buffer wasn't needed, it would be simpler to do.

I'll go back up and read the rest of the thread now...  :-[

Oops myself!  :-[  Sorry I misread your question completely.

Given that I don't need the buffer, I may try to do the mod without it.  Now that I understand the impedance issues better, it all makes sense.  I could always put the buffer in later if I need it, I suppose.  Additionally, I was thinking I might try to swap out that thumbdrive door for a metal plate so I don't mess up the chassis.  I wish I could do the mod on a US-20 or similar box, but the cost of the box, extra GK cables, etc., seems a bit steep, since I don't already own any of those parts.
justin

GR-55, VG-99

samandlyn

Quote from: justinmorell on May 02, 2011, 09:37:41 AM
you can send the magnetic pickup signal and the modeling signal to different points in the GT-8 signal chain depending upon where you place the send/return in the GT-8 patch chain.  For example, with one patch on the GT-8 (or using it in manual mode, which is often really handy) you could have the magnetic pickup run through a compressor and distortion, then turn the loop on and have the modeling tone--fed out through the GR-55 "Guitar Out" jack--hit the GT-8 after the distortion and compressor.  I could definitely see the advantage here.



Justin,

thanks for sharing your setup , that's really helpful.
Man , there's your PhD right there, you can stop studying now ;) ;)

Re: my suggestion, yes the idea was to have your normal guitar sound not coloured by the GR55, and to be able to use the SR loop in the GT8 ( I have the GT10) when you want it.

Just a thought.

Thanks ,

Sam