SOLVED: FM9 and Marshall JVM410H Noisy Effects Loop

[VegasDude]

Hey all,

I have a Fractal FM9 that I'm trying to use through a Marshall JVM410H's effects loop. I'm using the 4CM and all the cables are "humbusters" dual ring 1/4 instrument cables. The clean channel sounds fine but OD1 and OD2 are noisy as heck... way too noisy.

Any ideas on how to eliminate this noise? Are there any physical noise gates smaller than rack mount that work? None of the noise gate blocks in the FM9 do anything for this noise. I also adjusted the boost/pad function on output 3 as high as it can go. It helped a tiny bit but still way too noisy. Are there any amp mods that can be done to eliminate the noise? Or settings I may not have tried?

Thanks!

 

[sprint]

You can try putting a good quality iso transformer either just before amp input or after amp send - I use one of these in both locations to solve some 4CM hum issues with my H+K head without changing tone/feel.

Other thoughts:

• Use a unity gain loop (3).
• Turn up the output (to amp input) 's boost/pad - but note that you'll lose some output clipping headroom so keep an eye on the output meter as you turn it up.
• Use a power conditioner / make sure all connected gear is plugged into the same circuit.

Edit: The above assumes the noise issues in question are not coming from the guitar and/or natural gain of the preamp which is normally expected to some extent, and just managed with noise gates.

 

[Sine]

Or try with input noise gate and one after preamp section of amp. Works for me on my amps.

 

[VegasDude]

Or try with input noise gate and one after preamp section of amp. Works for me on my amps.

Do you mean a noise gate block? I already have one right after the input (after the MIDI block). Are you saying to add another one on the input of the return signal? I'm using 4CM so I do not have an amp or cab block. I've split my signal path into two: per the manual, one for before the amp (Input 1 to Out 3) and then another return after the amp (Input 3 to Out 1)

 

[killerburst]

Which loop are you using? I would rely on the insert loop to make sure you don’t have any phase issues with the parallel mix knob. It’s a start, anyway.

 

[elvis]

Are the cables HUMBUSTER or just TRS? The Humbuster should be TRS on one end and TS on the other, with the TRS end plugged into the FM9. In addition, only OUT 1 and OUT 3 have humbuster capability. Exactly how did you wire your system?

 

[VegasDude]

You can try putting a good quality iso transformer either just before amp input or after amp send - I use one of these in both locations to solve some 4CM hum issues with my H+K head without changing tone/feel.

An A/B Switchbox?

Other thoughts:

• Use a unity gain loop (3).

I believe I'm doing this. The Output knob for Output 3 (sending to the JVM Instrument Input) is all the way up. And even Output 1 (sending to the FX return) is all the way up (though reducing this doesn't change the noise anyway)

• Turn up the output (to amp input) 's boost/pad - but note that you'll lose some output clipping headroom so keep an eye on the output meter as you turn it up.

Done. Helps a tiny bit. But not enough

• Use a power conditioner / make sure all connected gear is plugged into the same circuit.

I'll have to try this. I have a Furman rackmount. Was hoping to ditch the extra rack case but will give it a shot

Edit: The above assumes the noise issues in question are not coming from the guitar and/or natural gain of the preamp which is normally expected to some extent, and just managed with noise gates.

Are there any of the noise gate blocks you'd recommend? And what settings and placement in the chain? I have 2 signal chains. One pre and one post JVM.

Thanks so much!

 

[unix-guy]

Are the cables HUMBUSTER or just TRS? The Humbuster should be TRS on one end and TS on the other, with the TRS end plugged into the FM9. In addition, only OUT 1 and OUT 3 have humbuster capability. Exactly how did you wire your system?

View attachment 121301

Exactly this.

"Dual ring" sounds like TRS. Humbuster cables are not TRS.

Further, "everything" should not use them - only the Output of the FM9 into the amp.

 

[VegasDude]

Are the cables HUMBUSTER or just TRS? The Humbuster should be TRS on one end and TS on the other, with the TRS end plugged into the FM9. In addition, only OUT 1 and OUT 3 have humbuster capability. Exactly how did you wire your system?

View attachment 121301

Ah!! I didn't realize that the ends were different for a humbuster cable. I am using TRS on both ends. I do have it wired as in the manual: Using Out 3 to send to the amp main input and Out 1 to send to the FX Return of the JVM. I now see, looking closer at the manual, that there is a difference. I missed it. So, is there a simple modification I can do to the cables to make the ends going to the JVM "TS" vs. "TRS"? Is it as simple as disconnecting the black lead from the "R" and connecting it to the sleeve?

 

[VegasDude]

Which loop are you using? I would rely on the insert loop to make sure you don’t have any phase issues with the parallel mix knob. It’s a start, anyway.

I'm using the Serial / Parallel FX Loop. The other loop is a power amp insert / serial loop. As I understand it, this loop is before the pre-amp master controls? I did not think this processes any signal after the pre-amp. Plus, I am using the JVM pre-amp. Maybe I misunderstand. Honestly, I don't like the wet/dry dynamic either. And don't fully understand the note about making sure no direct signal flows from the "effects unit" output. Does that mean that the "mix" in each FM9 block needs to be set to 100%? And the wet/dry mix is managed by the FX Level knob on the back of the JVM?

 

[VegasDude]

Exactly this.

"Dual ring" sounds like TRS. Humbuster cables are not TRS.

Further, "everything" should not use them - only the Output of the FM9 into the amp.

Yes! I think we're getting there. I'm going to try modding my cables if possible (see my response to Elvis). I'm hoping this makes a big enough difference. BTW, as you mentioned above, confirming, the connection between Guitar and Input 1 would be standard instrument cable. And input back into Input 3 from the JVMs send should be standard instrument cable as well? Only the Outputs from FM9 1 and 3 would have the TRS end of a humbuster. The TS end of the humbuster goes into the AMP.

 

[bertwarbutton]

In my Marshalls, triaxis etc I used a Decimator 2 pedal in the effects loop.. Killed the noise... Sorry can't comment on the FM9 method as I sold amp gear and replaced it solely with the FM9.

 

[VegasDude]

In my Marshalls, triaxis etc I used a Decimator 2 pedal in the effects loop.. Killed the noise... Sorry can't comment on the FM9 method as I sold amp gear and replaced it solely with the FM9.

So, did you place this pedal before the effects in the effect loop? Or after? It was in the same effects loop chain, right? ie FX Send > D2 > Effects unit > FR Return?

BTW, just watched some videos on the D2. Impressive!!! Doesn't seem like it stole any tone but did it steal any of the "feel"?

 

[sprint]

An A/B Switchbox?

I'm only using the ISO transformer part of those boxes - not the A/B. There are other ISO only boxes - just don't buy a cheapy or it'll noticeably affect your tone/feel.

Are there any of the noise gate blocks you'd recommend?

Check for how much of the noise is coming from your guitar by having it plugged in and listening (without playing) between guitar volume off and full up. If there's a lot more noise full up, a gate at input will help (gate type doesn't matter so much until you get to fine tuning). Noise from amp gain (ID'd with guitar off) can be suppressed with a gate block after the preamp, BUT, the main point I wanted to make above is to determine if your hearing hum issues that are separate and apart from expected guitar / amp gain noise that can be suppressed (not eliminated) with gates. The type of hum I refer to above wrt to the ISO transformers is eliminated by those transformers - not just suppressed as with a gate.

 

[bertwarbutton]

I had it in same effects loop just always on.

 

[Sine]

Do you mean a noise gate block? I already have one right after the input (after the MIDI block). Are you saying to add another one on the input of the return signal? I'm using 4CM so I do not have an amp or cab block. I've split my signal path into two: per the manual, one for before the amp (Input 1 to Out 3) and then another return after the amp (Input 3 to Out 1)

Yes, noise gate block. Way I use it is one in input block (not noise gate block because you have one in input block) and one (noise gate block) first after preamp section of your amp or after INPUT 3. 4CM also, no amp block from Fractal unit.

 

[VegasDude]

Yes, noise gate block. Way I use it is one in input block (not noise gate block because you have one in input block) and one (noise gate block) first after preamp section of your amp or after INPUT 3. 4CM also, no amp block from Fractal unit.

That actually did quite a bit of good! The gate I put before the amp did no good (duh!). But putting it in the 2nd part of my signal chain helped. It doesn't eliminate all of the noise. But helps. Amazingly, the Expander does more good than the Noise Gate. Do you know of any other gate blocks out there besides the ones that come with the FM9?

Now just have to fine tune for tone and trails vs. noise. I'll try it at rehearsal to see if it's enough or see if I need to invest in a Decimator II. Thanks so much for the suggestion

 

[Rex]

There are other ISO only boxes - just don't buy a cheapy or it'll affect your tone.

They all will affect your tone. Some more than others.

 

[killerburst]

I'm using the Serial / Parallel FX Loop. The other loop is a power amp insert / serial loop. As I understand it, this loop is before the pre-amp master controls? I did not think this processes any signal after the pre-amp. Plus, I am using the JVM pre-amp. Maybe I misunderstand. Honestly, I don't like the wet/dry dynamic either. And don't fully understand the note about making sure no direct signal flows from the "effects unit" output. Does that mean that the "mix" in each FM9 block needs to be set to 100%? And the wet/dry mix is managed by the FX Level knob on the back of the JVM?

Negative. The insert loop is after the preamp sections and before the master section. Plain, old-fashioned, unbuffered effects loop. Try it.

 

[toesalad]

Do you mean a noise gate block? I already have one right after the input (after the MIDI block). Are you saying to add another one on the input of the return signal? I'm using 4CM so I do not have an amp or cab block. I've split my signal path into two: per the manual, one for before the amp (Input 1 to Out 3) and then another return after the amp (Input 3 to Out 1)

A side note… the MIDI block does not have to be in your signal path, it can be put anywhere on the grid.