Helix + Marshall JVM410H + 4CM

[Axxxeman]

Hi folks,

 

being a newby on Helix I dare another question here.

I am using the HELIX just as a multi-FX-board and as a control panel for my Marshall JVM410H. I love the amp's sound and would not have another one (as long as the Marshall won't go down. If one day it would do so, I plan to use the HELIX' DI-OUT with an alternative set-list with amp, cabinet etc. directly into the mixer).

First step was to control the amp's sounds by MIDI Program change mode which worked absolutely perfectly. No need for the amp's footswitch anymore. :) 

Second step was using the 4CM in order to put the Wahwah at the beginning of the signal chain and delay etc. after the MARSHALL's pre-amp. I've been watching this video for instructions:

https://youtu.be/Wvz3L8bJb1w

Well, I've been doing as was said here, but the results were so bad, so that I had to switch back to standard send-/return (3 cables).

So, maybe someone can help me with this problem, by answering a few questions:

• My amp has 2 effect loops, one serial (preamp out, return) and one that can be used in a serial (by putting the mix knob on 100%) or a parallel mode (mix 50%). The latter has the big advantage, that the original signal stays in the amp while the Helix (when its effect mix configured correctly) delivers just the FX signal, while the Marshall mixes the original with the Helix' FX to an optimal sound ... in theory.
  Now in the tutorial it says, that the amp's SERIAL FX loop should be used. Well ... is that so, that good results can get achieved ONLY with the serial FX loop? I ask, because MARSHALL does explicitely not recommend this, if you are not using hi class studio rack effects. Well, no idea, whether the HELIX qualifies as such ... ;-)
• I learned, that in the HELIX' preset you have to add a send/return block each. But then, there is a "fx loop" block, too. Is this the same thing as one send with the return block combined?
• I DID make it work, even in parallel mode by putting the delay's mix to 100% and the amp's return mix to 50%. Sounded great. Problem was: when I chose a Helix' snapshot of the same preset that has no active effects but noise gate (as I do many times for rhythm sound), there is some screeching and loud humming that I cannot explain. Even when I turn the guitars volume to total zero, there is a feedback loop somewhere and I cannot find its cause. So I have no idea, where to search. But like this, you cannot use this setting at all. Anyone any ideas?

Sorry, if I repeat some questions for the hundredths time, but the forum's search routine could not find answers to my questions ... I appreciate any help, because I need the Wahwah and the delay. First one sounds crap in Send / Return, second one sounds crap in front of the Marshall ... HEEEELP!   :(

[fsambucaro]

So You only use the channels from the jvm? Everything coming from the helix is just FX with no amp modeling?

[Axxxeman]

So You only use the channels from the jvm? Everything coming from the helix is just FX with no amp modeling?

 

Right. And it is almost working, apart from the strange effect, that when switching by MIDI into the lower master volume setting (I don't even change channels here) and having the solo FX (reverb and delay) turned off, I get this feedback loop I can't explain. No level editing on the Helix, no preamp, no amp, no cabinet whatsoever. It is all happening in two snapshots of the same preset.

What I shall try next:

• Changing the send- and the return-blocks into a single fx-loop block
• Programming a sound from the scratch with one of the templates for 4CM inside the Helix and look, what happens. But this still will not explain how to run Helix FX in parallel amp fx loop

Another question here: I programmed most Helix effect blocks (reverb, chorus, phaser) as stereo effects, even when only using a mono output. Could this maybe have such an effect as described, that the signal gets double the volume, when turning the stereo effects in a mono surrounding off??? Hardly imaginable, but still ...

[fsambucaro]

I'm trying to do the same thing with my EVH 5150. I'll keep you posted. Choosing stereo fx will definitely do this. Run mono. I would look at YouTube videos from Richie Castellano. He has over 200 minutes explaining how he runs his helix.

[fsambucaro]

It's called Line 6 Helix- switching amp channels with 4cm and snapshots

[Axxxeman]

So far I unfortunately made no big progress on the main topic. All is running now as it would be expected but for two unacceptable issues:

• There is a feedback loop somewhere in the signal chain and I cannot find its source. Whenever I am not playing the guitar and the Helix' volume pedal is up, there is a fast increasing screaching sound just like a really bad feedback. But mind, this is happening with guitar volume being cut to zero! Still feedback rising, so it is NOT the classical guitar/amp feedback. It happens somewhere else. And it happens even with NO FX whatsoever turned on apart from noise gate!
• The FX that are put in the Send/Return path do not really convince. A delay, for example has an audible quality drop. With a mix rate set to 50% it should be equally loud as the original signal, but it is not, it is muted. And the sound itself is kind of mutilated (little high frequencies), independently, which delay type I choose.

So this solution is worse than with the cheap DigiTech multieffect pedal I was using previously ...  :wacko: It is also worse as using the classic 3-cable method (send/return) which I do not want to use, because then the HELIX' wahwah pedal sounds absolutely lollipop. 

To my assessment, both problems mentioned above are caused by the same error. If there is any MARHALL user out there who knows how to avoid this signal chain mess, please help ...

[ricksteruk]

Yes it sounds like the problem is being caused by one thing - parallel mode.

It is much harder to get your head around and has a lot more problems than serial mode - most likely none of the presets you will see anywhere will work for you - none of the factory presets for example should ever be turned on!

 

Firstly - the mix ALWAYS needs to set to 100% on the delay and reverbs.  

You NEVER EVER want any dry signal to go through Helix and back into the amp - this means you can't use any FX that might include the dry signal like tremolo or chorus (these would need to be in the PRE amp part of 4cm - which is where you normally would put them anyway thankfully).

 

If you bypass the delays FX blocks (or have a patch with no FX blocks at all) then you will be sending some of your dry guitar signal back through Helix - which is most likely causing your feedback.   And also.. the dry signal through Helix is delayed by one or two milliseconds due to the A/D and D/A converters so when it gets back to the amps parallel FX return and is mixed with the original dry guitar sound then you can get nasty phasing interference between them (which is probably what you describe as the sound being a bit mutilated)

 

You cannot simply Bypass an FX block - you need to add a gain block to turn down / off the Helix output on that path.

 

You can use parallel with Helix if you 100% understand how to rig it up - but in my opinion any minute sonic benefits are totally outweighed by the lack of flexibility you are making for yourself - you lose so many possibilities.  For example - a post amp volume volume pedal.... (which needs to live in the FX loop.. and only will work in serial mode)  I love using a delay pedal after my distorted amp and then use a volume pedal to fade in and out the distorted sound into the delay.   This isn't the same thing as putting a volume pedal before the amp... it sounds different... as your volume is pre the distortion so when the volume pedal is low you are feeding a clean signal into the delay.. not a quiet distorted one.

[Axxxeman]

Wow, that sounds like a good step into the correct direction, thank you very much, Rickster!!!

 

But some question keeps being open. I was experimenting with parallel mode only, but did not yet establish it. My experiences come from serial FX loop use of the parallel Marshall FX loop path. If you set the Mix-knob of the Marshall to 100%, then you get a perfect serial loop ... That is at least, what the Marshall manual is stating. But I am no technician at all and there might STILL be a parallel "component" in the game. It seems plausible to me, after what you wrote. But if Marshall is wrong here, then how to correct it?

 

There is another FX path (pre-amp out / power amp in), but Marshall does not recommend using it, but with hi-class studio effects. And ... I did not get it to work with the helix so far. No signal coming through at all. With the cheap DigiTech I had previously it worked (3-cable-method), but not with Helix and 4CM. Any suggestions what could be the cause of this prob??

[Joepeggio]

I do not own a 410h, but have used cable. I would used the serial only loop on the 410 set at -10. Use a single send/return block. Be sure mix is set to 100%.

 

Always start with a blank preset in the Helix. Just some thoughts

[ricksteruk]

Wow, that sounds like a good step into the correct direction, thank you very much, Rickster!!!

 

But some question keeps being open. I was experimenting with parallel mode only, but did not yet establish it. My experiences come from serial FX loop use of the parallel Marshall FX loop path. If you set the Mix-knob of the Marshall to 100%, then you get a perfect serial loop ... That is at least, what the Marshall manual is stating. But I am no technician at all and there might STILL be a parallel "component" in the game. It seems plausible to me, after what you wrote. But if Marshall is wrong here, then how to correct it?

 

There is another FX path (pre-amp out / power amp in), but Marshall does not recommend using it, but with hi-class studio effects. And ... I did not get it to work with the helix so far. No signal coming through at all. With the cheap DigiTech I had previously it worked (3-cable-method), but not with Helix and 4CM. Any suggestions what could be the cause of this prob??

 

 

No problem :)

 

Yes I see your point about the possibility of there still being a parallel signal even when the mix is 100% and it should be off.   I have had this happen with one of my amps before actually.  (it's my current H&K switchblade I think... you still get a very very small amount of signal through even when the loop is in series mode.. but it is is slight that it does not affect the sonic quality of the amp when you are playing.. I only noticed it when I was using headphones with Helix in 4cm for some 2am practice so there should have been silence.. but a TINY bassy signal came through the speaker).  

   

You could test your Marshall for this by plugging the guitar into the front of the amp and then running the Marshall's Series/Parallel at 100% with Helix in the loop - but turned off so that no signal comes through Helix.  Then if you can hear any sound through the Marshall you know there is a leakage.

 

Once you've decided on how to plug it all in - the next step is setting levels.  Choosing instrument / line level on Helix and -10/+4 on the Marshall, as well as setting the send and return block levels in Helix so that the overall signal level / gain through the Marshall remains exactly the same as it was before adding Helix.  I can talk you through this if you need help.  

[Axxxeman]

 

You could test your Marshall for this by plugging the guitar into the front of the amp and then running the Marshall's Series/Parallel at 100% with Helix in the loop - but turned off so that no signal comes through Helix.  Then if you can hear any sound through the Marshall you know there is a leakage.

 

 

Ah, good idea. I'll try that first thing next time in rehearsal room. And if there is a leakage, might that eventually be a reason for a  repairing by Marshall on warranty? Anyone with experience in this field?

 

And if there is no leakage ... what else could be the possible reason for such a strange feedback loop?

 

Once you've decided on how to plug it all in - the next step is setting levels.  Choosing instrument / line level on Helix and -10/+4 on the Marshall, as well as setting the send and return block levels in Helix so that the overall signal level / gain through the Marshall remains exactly the same as it was before adding Helix.  I can talk you through this if you need help. 

 

 

That's very nice from you. When I finally get rid of the main problem and I do not succeed to get the levels straight myself, this will surely help. Thank you!

 

 

I do not own a 410h, but have used cable. I would used the serial only loop on the 410 set at -10. Use a single send/return block. Be sure mix is set to 100%.

 

Always start with a blank preset in the Helix. Just some thoughts

 

All of this I have already done / tried. So far in vain unfortunately ... Thanks! :-)

[Axxxeman]

Update on the issue: the Marshall JVM410H has a defect serial loop, which I verified with the testing method, described by RicksterUK and - to be sure - by cables in the S/R-Loops that led nowhere. So I could be sure that the sound coming was not a rest signal running through the turned-off Helix. The amp is heading back to Marshall now. I really do hope that this will solve the problem. The dealer said, it might not, because this special head amp was highly overbred for gain and too much gain could as well be part of the problem ... I will report once I got the amp back.

[Woodlandsu35]

I'v been working the 4cm  for very long time,  and I owned a JVM 410 too (now a 2555 besides a MKV).  

 

In terms of sound quality I can only speak in highest regards of the Helix.  With the Marshall  I used the serial option mainly, due to 

the need to regulate volume after the preamp. I experienced no issues at all with the JVM concerning the serial/parallel loop.

 

To match the correct levels and impedances in a 4 CM Setup (or 7 with 2 amps), and hum elimination, is challenging,  but the key to maintain sonic integrity.

Its worth the effort to keep the patience to work yourself through.

[jamm8805]

Any update?

[travislaack]

Sorry to bump and old thread but I was having the same issue.  410H squealed to microphonic feedback with my Helix in 4CM.  I tried balanced and unbalanced cables,  plugging the Helix into anther wall socket away from the Marshall, activating ground lift, etc but it would work for a bit and then start to squeal into feedback that was ear splitting.  I returned the amp to GC and have another on the way.  Anyone have any ideas of what it could have been?  I am worried the JVM loop won't be compatible with the 410h in 4cm which would mean I would have to replace my helix with pedals

[AC1DF0X]

What a coincidence. I've just got a Helix, I use a JVM, and I'm using the 4CM without any issue. In fact that's the main reason I upgraded to the Helix from the little Zoom multi-FX unit I had before.

 

Here's how my Helix is set up. I did watch a few videos, but it seems like everyone goes about this in different and sometimes really non-intuitive ways. I basically disregarded everyone else's advice, and figured this set-up out for myself. I'll try to explain as concisely as possible:

 

- Set JVM's FX Loop Level to 100%, and make sure the little button is pulled out.

- Set Send/Return 1 on the Helix to "Instrument" in Global Settings > Ins/Outs.

- JVM's Send is connected to Helix's Return 1. JVM's Return is connected to Helix's Send 1.

- Guitar is connected as normal to 1/4" guitar in, and left/mono out to the amp.

- Top row is set as "Input - Guitar", and "Output - Multi".

- Bottom row is set as "Input - Return 1" and "Output - Send 1/2".

- Highlight the output block on the bottom row and boost the output by +1 or 2dB. (The JVM FX loop does lose a bit of volume.)

- Effects that you want to go in front of the amp (wah, drives, modulation) go on the top row.

- Effects that you want in the loop (noise gate, delay, reverb, looper) go on the bottom row.

- See attached picture, you should have something like that, and you're in business.

 

I'm not sure why everyone gets stuck on the send/return blocks, as far as I can see they're totally unnecessary. If you're not using the second signal chain for some other reason, I can't see why you wouldn't just do it this way.

 

Also- I've tried using both the loops on the JVM, and I had better results with the serial/parallel one for some reason. Not sure exactly why. I believe the serial loop is line level (it goes directly between the preamp and power amp in the circuit), and you have to change settings on your Helix to reflect that, but for some reason it just doesn't work as good. The other benefit of using the serial/parallel loop is it goes before the amp's reverb, in case you still want to use that, and also allows you to footswitch the whole loop on/off if you need to.

 

The setup I have described here is super flexible, you can do things like record a clean loop, and play over it on a different amp channel while retaining perfect sound. Having a gate in the loop as well as a gate at the input stage is essential too, because the JVM has an ungodly amount of background noise, and you can completely clean it up. It does take some trial and error to figure out the threshold for the gates, but I ended up setting the gate in the loop to ~25-30db and it eliminates any noise from the amp.

 

Hope this helps :)

 

[travislaack]

Thanks for the info!  The way you have it set would be the way I was thinking would be the "standard" approach.  What people want to do (and I am growing a little unconcerned about) is put a Send/Return block in there to bypass the JVM preamp and plug in another preamp model, thus giving you a Mesa preamp going through your JVM.  It's very cool when you have a 5150 and need a clean channel, but since the JVM has so much versatility seems a little unnecessary.  Would you mind doing me a favor and trying it the way I had it configured (as pictured).  This would get you the JVM if the Send Return block is engaged and the Mesa Mark IV if the FX loop is off and the Amp block is On.  What happened for me (with the JVM loop all the way to serial) was that when I had the Send Return block on and Amp Block Off and Delay On I would get a horrible repeating feedback.  I do think it was a defective JVM FX loop (it was a used guitar center purchase) so I have a new one on the way from Sweetwater.  I am just nervous this won't work and I rely on the Helix for all my FX.  For Midi, after the picutures I have a link to the guide I was going to use.

 

 

 

 

 

https://line6.com/support/topic/28901-marshall-jvm-channel-switching-with-helix-midi/

 

Thank you so much for the help!  It is helping to ease my mind that it will work.

[travislaack]

Haha.  One more thing @AC1DF0X , I apologize for the dust in those pics.  Your Helix looks so pristine compared to mine!

[AC1DF0X]

Ahh I see what you are going for, bypassing the JVM preamp to run an amp model in place of it. I can't see any reason it shouldn't work that way.

 

I had briefly considered that as an option myself, I can see it being handy, but I haven't got around to experimenting with it yet. If I'm not mistaken there should be a way to do it without having to change the method of connecting the cables though- You could still do it with the "normal" 4CM wiring, and just make a preset with different I/Os, right? I would have to have the Helix in front of me, I can't summon the brain power to map it out in my head haha.

 

Come to think of it, that does mean you'd want to use the line level serial loop, not the serial/parallel one. If I remember correctly, the JVM's circuit puts the serial loop directly between the pre-amp and power-amp, so using that, you would totally take the pre-amp out of the equation. But using the serial/parallel loop, you'd still be pushing that signal through the last valve stage of the pre-amp. Might make a difference, might not.

 

Anyway I'll give your method a try when I get chance and report back. The JVM effect loop does behave strangely compared to other amps I've owned (being tube driven might account for some of the strangeness), but I can't see any reason the issue you're having would happen, as long as the loop is working properly.

 

(And yup, it's brand new, it won't stay that way for long ;) )

[travislaack]

@AC1DF0XYep, that's the reason.  That being said, I cared when I had 5150s or Mesa's.  I would use this method to get a real channel on a 5150 or a 5150 or Marshall high gain tone on a Mesa.  It added another channel the amp was missing.  With the limited time I had with the JVM, I think that point is moot.  It had a great clean, crunch, and then a Mid focused High Gain and Mid Scooped High Gain.  Really, all I could ask for out of an amps offerings.

 

I would love to hear what you experience is cabling it the way I do.  I really am hoping that since it was a used amp from GC that the FX loop tube (or other FX loops related component) was bad and that the new one I have arriving next week will work just as well as the 5150 and Mesa does in this configuration.

 

To recap, what I experienced was on OD 1 or 2 in Orange or Red mode with the gain around 3-4 out of 10 and the channel volume at 8 out of 10 but Master Volume at 1 out of 10 I would get an awful screeching noise that couldn't be gated or stopped.  Turning on the delay in the loop (you can see it above) caused a massive feedback loop that also couldn't be muted without turning off the loop.

[Kingkid]

I have the same amp and Helix!! 1> Make sure your using the 4 cable method, from Helix to amp!! Dont use any amps at all from the out of Helix to the input of the amp. 2. Jvm cant handle any amp in the effects loop!!

[travislaack]

@Kingkid  I was using 4CM, but have it wired as pictured above.  Is that how you have it wired or do you wire it a different way?  Thanks for the help!  BTW, the preamp pictured after to loop was turned off so it isn't part of the chain.

[AC1DF0X]

On 10/24/2021 at 1:55 AM, travislaack said:

@AC1DF0XYep, that's the reason.  That being said, I cared when I had 5150s or Mesa's.  I would use this method to get a real channel on a 5150 or a 5150 or Marshall high gain tone on a Mesa.  It added another channel the amp was missing.  With the limited time I had with the JVM, I think that point is moot.  It had a great clean, crunch, and then a Mid focused High Gain and Mid Scooped High Gain.  Really, all I could ask for out of an amps offerings.

 

I would love to hear what you experience is cabling it the way I do.  I really am hoping that since it was a used amp from GC that the FX loop tube (or other FX loops related component) was bad and that the new one I have arriving next week will work just as well as the 5150 and Mesa does in this configuration.

 

To recap, what I experienced was on OD 1 or 2 in Orange or Red mode with the gain around 3-4 out of 10 and the channel volume at 8 out of 10 but Master Volume at 1 out of 10 I would get an awful screeching noise that couldn't be gated or stopped.  Turning on the delay in the loop (you can see it above) caused a massive feedback loop that also couldn't be muted without turning off the loop.

 

Alright so I tried your method (I think I got it right at least, as a disclaimer I might have done something differently without realising) and it seems to work okay for me.

 

I did notice that running the channel volume that high gives you a lot of background noise, which the noise gates didn't handle very well without cranking it up to a level that really interferes with your playing. Using my EHX Silencer instead worked perfectly however, but the noise gate on the Helix seems to work a different way. I think the channel volume cascades into the next stage after the loop and drives the PI stage a bit hard maybe? I feel like those channels are definitely intended to be played with a higher headroom kind of setting, rather than driving the PI. Also potentially of note is that I'm not running the stock preamp tubes (Marshall uses JJs as stock IIRC, I put a set of Shugangs in mine) so maybe that has some influence. Shouldn't be drastic though.

 

But yeah in general it sounds like the amp you had definitely had a problem with the loop. Your new one should work.

 

My task for today is figuring out MIDI switching... I'm hoping there's a way I can set it up to simply replicate what the JVM's actual footswitch does on a separate patch, but we will see.

[travislaack]

@AC1DF0X  Thank you for testing.

On the helix I run the Precision Horizon gate at the start and in the loop; setting the threshold to like a 3 out of 10 in the loop.  For the other amps (5150 types) it worked great at shutting down the hiss and noise.

 

Let me know if that guide helps with the midi programming.  I had my EVH amp set so I could press a footswitch to engage all effects in a scene and change channels.  It was great.  I am hoping to configure the JVM the same way.

[travislaack]

@AC1DF0XWhere do you usually run your Channel volumes?  Maybe a problem I have is my default behavior is to crank the channel and then tune up with the Master starting at 0 and going up to achieve what I want level wise.  Maybe I should go more 4 out of 10 on the channel and crank the master more...

[AC1DF0X]

I usually keep the channel volumes around 11-12 o'clock. It starts adding saturation above that point I've noticed, which is desirable for some sounds (you get a good authentic Plexi crunch that way keeping the gain low), but not desirable for the kind of tight thrashy tones I want on the OD1-2 channels. My gain is usually 10-11 o'clock on those channels too, and never above noon.

 

The JVM is a very modern amp so it is designed for plenty of headroom, it doesn't start sagging on you until you have that master well above halfway, and that's already deafening. The masters are meant to be your main volume level control, or at least, I assume that's why they went to the effort of giving you two which are foot-switchable for boosts. Everything before that is tone shaping.

 

I got the midi figured out pretty quickly all considered, thanks to that guide. Unfortunately it isn't possible to replicate the JVM default footswitch behaviour, which would have been nice, but the next best thing for me is having a preset for each channel, with each mode saved as snapshots within them. The view mode that gives you 4 presets and 4 snapshots on screen works very nicely with that config.

[travislaack]

@AC1DF0X  That makes sense.  I will with the channel volume down a bit.  I have noticed that with the helix and loop engaged I do get tone suck.  It darkens and lowers the tone a bit.  I have my inputs/outputs set the same as you and I did replicate your settings but there is a noticeable darkening of the tone.  I wish I had a stomp box to check against it to see if it works.  The new amp is acting better but I can reproduce the issue by OD2 Red, Gain at 5 out of 10, channel at 10 out of 10 and master at 5 out of 10.  Not that I would use that but I was able to reproduce the error (loop and delay enabled).  Thank you for helping me with this!

[AC1DF0X]

It's mostly just volume drop because the loop isn't true serial- If you select the output block for send 1/2 and give it +1-2dB of boost going back into the amp, it'll take care of it. Your ears will perceive it as tone suck simply because it's quieter. There's also the button on the back next to the loop that affects the send volume, so try it on and off, I can't fully remember which way around it is.

 

If I was you I'd go back to basics using the regular 4CM, then set up a new preset with guitar input going straight to the effect loop output, that you can switch to when you want to use amp models. That way it just entirely skips the pre-amp and should work with no problems.

[travislaack]

@AC1DF0X  one last question, how do you wire your ehx silencer with the helix and the Jvm?  I am trying to figure out how that routes to the helix and loop with the jvm in 4cm.

[AC1DF0X]

Pretty straightforward. Guitar > Helix > Amp, then Send > Silencer > Helix > Return.