Boss GX-100 Multi-effects pedal on a JCM800 SC

[Vortac]

Alright y’all, this rookie here needs some advice and pointers regarding multi effects pedal and tube amps.

A little background…

I got my first tube amp about a year ago, love the thing. I slowly built a pedalboard with the basics (tuner, compressor, MXR classic distortion, tube screamer, holy grail reverb, Joyo delay, modded GE-7 EQ, JHS black box, chorus…). But I also wanted to start experimenting with multi effect pedals and patches, so I got a GX-100, exclusively to play around, tweak effects more in depth and see how it would be to have a one stop shop for all effects, albeit I have zero interest in amp modeling, I’m happy with my JCM800, just thinking about effects here.

I’ve never messed with multi-effects pedals, so here are my concerns…

1). With the GX-100 set up in a 4CM, I noticed that immediately all knobs on the amp itself are disabled, I’m thinking this is normal , since the control now lays on the Gx-100, not the amp itself (right?). However, isn’t there an option with multi effect pedals were I can still keep the raw sound of my tube amp and just feed it effects from my multi effect processor?

2). Considering question number 1 above. Is a multi effects pedal intended then for use on SS or modeling amps instead and not tube amps? Is it a complete disservice to a Marshall JCM800 to go and hook a multi effects processor to it?

If I can’t preserve the original base tone of my Marshall with the multi effect processor, it seems kind of a waste of time, the way I see it it would be stupid to hook a ME pedal trying to model an Amp that I already have, just to add effects to it. Am I missing anything? Am I way off here?

Would I be better off keeping the pedal board connected to Marshall like I had it and just get a modeling or SS amp to connect the GX-100 to?

I don’t gig, just play to backing tracks at home and occasionally get together with friends to jam together, but nothing serious or advanced...

Any input would be greatly appreciated!

 

[Gain Man]

What do you mean with "all knobs on the amp are disabled"? The amp itself wouldn't know or care if you have a multi-FX unit hooked up.
I know what the 4 cable method is and I have used it successfully, but just so that we are on the same page: how exactly did you wire things up?

 

[fitz]

If you're not using the front-end preamp effects from your multi gizmo, just hook it up in the loop for the TBE - No need for 4CM.
That's how I wound up using my ME-80 (wouldn't do 4CM) and my GT-8.
But the 4CM should be working - check your wiring layout.
You should be able to run a clean front end and use the amp's preamp.

 

[mark123]

4CM is guitar into input of GX-100, effects loop out of GX-100 to front of amp, amps effects loop out to GX-100 effects loop return, GX-100 output to amp effect loop return.

 

[Vortac]

All good points. Checked the cables, all connected the right way tho…

 

[mark123]

All good points. Checked the cables, all connected the right way tho…

You must not have the effects loop active in the GX-100 then.

 

[Vortac]

What do you mean with "all knobs on the amp are disabled"? The amp itself wouldn't know or care if you have a multi-FX unit hooked up.
I know what the 4 cable method is and I have used it successfully, but just so that we are on the same page: how exactly did you wire things up?

EQ knobs, presence, gain and volume do not work on the amp when the MFX unit’s connected. Just double checked cables, they’re connected right.

 

[Gain Man]

EQ knobs, presence, gain and volume do not work on the amp when the MFX unit’s connected. Just double checked cables, they’re connected right.

That sounds like the signal is going straight into the power amp and entirely bypassing the preamp. So as somebody mentioned before, maybe the FX unit's loop is off or not working. That is the only explanation that makes sense.

Is it possible that the FX unit has a parallel loop which is mixed to "dry"?

So just to confirm, your signal chain is like this:

Guitar > FX unit "Input" > FX unit "Send" > amp "Input" > amp "Send" > Fx unit "Return" > FX unit "Output" > amp "Return"

Correct?

 

[mark123]

EQ knobs, presence, gain and volume do not work on the amp when the MFX unit’s connected. Just double checked cables, they’re connected right.

Is the effects loop on the GX-100 active? If it's bypassed then your preamp is also bypassed and you're going straight into the effects return.

 

[Vortac]

Follow up…

The effects loop is active. 4CM is set up correctly, what I was missing was a S/R block on my chain on the MFX unit. So I added it, got my pre-amp knobs on my jcm800 back, albeit I had to turn the volume on the amp all the way up in order to hear anything out of it.

So that part is solved, the downside is the sound coming from my amp now while on this set up is nowhere near the tone I can get without my GX100 and just using my old pedal board with a few delay and chorus pedals on the effect loop of the amp (again, all effects off on MFX unit).

Using a GX-100 With the 4CM, adding a S/R block to the chain and selecting no amp modeling on the MFX unit provided a sound out of my amp that I thought would be minimally colored, and very close to the amps original tone (with zero effects) , it’s not close at all, I gotta be doing something wrong… 🤔

 

[mark123]

Where in the chain is the send/receive block?

 

[Vortac]

Wah -> Comp->OD->S/R->Rev->dlay

I didnt put an AMP block anywhere...

 

[Mike J]

Do you have a speaker cab model or IR enabled? That would kill the tone when used with the 4CM on a guitar amp.

 

[mark123]

Do you have a speaker cab model or IR enabled? That would kill the tone when used with the 4CM on a guitar amp.

Yeah, I'm coming from the old school Roland GP-100. You can literally set the type of amp you're using and if it's going into a guitar cabinet or not.

OP, just to be clear, have you read the owners manual and the startup guide?

 

[peterplexi]

EQ knobs, presence, gain and volume do not work on the amp when the MFX unit’s connected. Just double checked cables, they’re connected right.

Both loops in the amp and effects unit must be turned on. Also, make sure all amp model blocks are off in the effects unit. You should be able to run front end effects like boosts, ods, eq, compression into the amp front end and place all time based effects after the amps preamp.

 

[KraftyBob]

Follow up…

The effects loop is active. 4CM is set up correctly, what I was missing was a S/R block on my chain on the MFX unit. So I added it, got my pre-amp knobs on my jcm800 back, albeit I had to turn the volume on the amp all the way up in order to hear anything out of it.

So that part is solved, the downside is the sound coming from my amp now while on this set up is nowhere near the tone I can get without my GX100 and just using my old pedal board with a few delay and chorus pedals on the effect loop of the amp (again, all effects off on MFX unit).

Using a GX-100 With the 4CM, adding a S/R block to the chain and selecting no amp modeling on the MFX unit provided a sound out of my amp that I thought would be minimally colored, and very close to the amps original tone (with zero effects) , it’s not close at all, I gotta be doing something wrong… 🤔

I run a Helix LT 4CM through my tube amps so I have experience with the setup you are currently running. It can be a little more involved than just plugging in the cables - as you've discovered - but it can be worth it. If your Boss has these options, check your outputs for impedance settings as well as Line vs Instrument settings. That can affect your tone.

Feel free to hit me up with other questions. Even though we have different units a lot of the overall setup is likely similar. And not saying I know everything about this, I don't, but I may have already gone through things you might run into.

 

[PowerTube44]

You must not have the effects loop active in the GX-100 then.

This is the answer. With the effects loop turned off on the GX-100, it becomes the equivalent of running directly into the Effects Return on the amp, where the amp's preamp is bypassed entirely.

I don't have a GX-100, but I've had a GT-100 for a few years. On the GT, you have to make sure you have the S/R (Send/Return) block turned on. I'm sure the GX is similar.

 

[PowerTube44]

Maybe this will help?

 

[Vortac]

Thanks all, I’ve found the solution.

Switched output setting in GX-100 to Line/Phones instead of Tube Combo 1x12, put the S/R block in the right spot, eliminated Amp block on signal chain and that did the trick, got my pre-amp back and regular Marshall tone.

Thanks a bunch for all the input guys, much appreciated!!

 

[mark123]

Thanks all, I’ve found the solution.

Switched output setting in GX-100 to Line/Phones instead of Tube Combo 1x12, put the S/R block in the right spot, eliminated Amp block on signal chain and that did the trick, got my pre-amp back and regular Marshall tone.

Thanks a bunch for all the input guys, much appreciated!!

Excellent! 😄👍