Getting a lot of noise (hiss/white noise?) when in 4CM, anyone have experience/suggestions?

SinglecutGuy

SinglecutGuy

Inspired
FM3 into Friedman Runt 50 head, using 4CM. I watched Leon Todd's video on setup, and did a basic patch as follows:

IN 1---> Drive 1---->OUT 2
IN 2--->Delay 1--->Reverb 1--->OUT 1

EDIT: (Originally had typed the wrong cables, which would have cause an issue, but I am and was using the correct cabling, as per the manual).
I'm using a standard guitar cable from the guitar to the FM3 input. I'm using an XLR-F to 1/4" TS cable from the Out 1 to FX Return. I'm using a standard guitar cable from the FX Send to the Input 2. I'm using a standard guitar cable from Out 2 to the amp's input.

The problem is only through the effects loop of my amp. If I remove the cables from the effects loop in the back of the head, and just use the Drive block into the front of the amp, I have no noise. As soon as I put the effects loop cables into the amp, I have hiss. It's significantly more apparent on the Gain channel of my head (naturally).

I did all the SUM L/R options, and adjusted the output levels on the FM3 on the knobs and in the I/O. I also adjusted the "Pad" in the I/O as mentioned and suggested in the manual, and while this helped lower the noise floor, it was still too loud for gigging purposes.

I am not using a Humbuster cable, as I don't have "hum" problems, I have "hiss"/"white noise" sounding problems. Any suggestions? Has anyone else encountered something like this in 4CM with the FM3?
 
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SinglecutGuy said:
I'm using an XLR-F to Male TS cable for going into the front input on my head
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The XLR is Out 1. In 4CM, Out 1 needs to be hitting your amp’s FX loop return.

Should be:
  • Guitar cable to FM3 Input 1
  • Humbuster from Output 2 L to amp front
  • Standard TS cable from amp’s FX loop send to Input 2 L
  • XLR-F to male TS cable from Output 1 L to amp’s FX loop return.
 
philipacamaniac said:
The XLR is Out 1. In 4CM, Out 1 needs to be hitting your amp’s FX loop return.

Should be:
  • Guitar cable to FM3 Input 1
  • Humbuster from Output 2 L to amp front
  • Standard TS cable from amp’s FX loop send to Input 2 L
  • XLR-F to male TS cable from Output 1 L to amp’s FX loop return.
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I mis-typed there. I DO have the XLR-F to TS going from Output 1 to the FX return. I have it done as described in the manual.
 
Ah ok, good to have that cleared up.

What are your output levels set to? Specifically, Out 2? I believe it should be all the way up for unity gain heading into the front of your amp, while Out 1 controls the final level going to your amp fx return.
 
Output 2 was turned all the way up, yes. Output 1 was set to "noon", and adjusting that up or down, will raise and lower the "hiss" sound, as described in my first post, as well as the overall level, obviously. Again, using the "pad" settings on the FM3 lowered this noise floor, while not adjusting the volume (which was good), but even on the 18dB pad, it was still too much hiss.
 
I don't use my FM3 in a 4CM setup but I did retire my AX-8 to a 4CM setup with my 2203x. I experience some of the strange high frequency white noise in that setup. It is worse if I don't set up the gain staging correctly to optimize it.

I had read that Cliff said that the AX-8 was designed for a wideband response to get the best fidelity for FRFR systems - or something like that. The FX-8 was designed with some additional caps on the outputs to filter out the frequencies where this white noise resides. He said that the AX-8 could be factory modified with the caps to give it the reduced bandwidth of the FX-8 but he did not recommend it if you still want it use the AX-8 as a standalone modeler.

I might not have all the details correct but I wonder if the FM3 has the same design for a wideband response and not optimized for a 4CM setup.
 
I use an Axe-Fx II in 4CM with a 5150 II head and I ran into the same problems you're describing with my first couple attempts at 4CM. I wound up ordering some humbuster cables that really helped make my setup quiet enough for me to be happy with. It can also help to have all of the gear in your 4CM rig plugged into the same power strip and wall outlet.
 
Brett336 said:
I don't use my FM3 in a 4CM setup but I did retire my AX-8 to a 4CM setup with my 2203x. I experience some of the strange high frequency white noise in that setup. It is worse if I don't set up the gain staging correctly to optimize it.

I had read that Cliff said that the AX-8 was designed for a wideband response to get the best fidelity for FRFR systems - or something like that. The FX-8 was designed with some additional caps on the outputs to filter out the frequencies where this white noise resides. He said that the AX-8 could be factory modified with the caps to give it the reduced bandwidth of the FX-8 but he did not recommend it if you still want it use the AX-8 as a standalone modeler.

I might not have all the details correct but I wonder if the FM3 has the same design for a wideband response and not optimized for a 4CM setup.
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Maybe I should put an email in to Fractal. Or is there a setting that can be changed from FRFR to Guitar Amp? Or something like that, I wonder.
 
jljesse said:
I use an Axe-Fx II in 4CM with a 5150 II head and I ran into the same problems you're describing with my first couple attempts at 4CM. I wound up ordering some humbuster cables that really helped make my setup quiet enough for me to be happy with. It can also help to have all of the gear in your 4CM rig plugged into the same power strip and wall outlet.
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I'm up for trying a Humbuster cable, but I may just make my own. Looks like it just takes a TRS balance cable and ties the Neutral wire into the Ground. Nothing overly special there, unless I'm missing something.

For the record, I do have all the power in the same Furman power strip. However, it's worth mentioning again, that I don't have "ground hum" issues. Just high frequency hiss/white noise.
 
I've tried, but the 4CM has too much noise and too many AD/DA conversions going on for my taste. Here's the pedalboard I'm using. It's the 4CM but with analog drives in front of the amp and the FM3 really as FX and Clean channel + you get more switches for scenes or fx. The Mooen GEC5 sends midi to the FM3 and switches also my amp channels from rhythm to lead and volume boost of the amp. IMG_20210427_233318.jpg
 
I’m not using my real amps much now, but when I did I had better luck using the 4CM setup where you use only Output 2. It resulted in less hiss in my case, but maybe I just had a bad XLR to TS cable.
 
marshall2553 said:
You run your pre and post rows into the output 2 block and pan them 100% left and right.
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This is what I do and have no hiss or extra noise. Using a Mesa Rectoverb 25 or Electra Dyne. No humbuster cables.

Maybe it’s something to do with the particular loop in the Runt 50?
 
TubeStack said:
This is what I do and have no hiss or extra noise. Using a Mesa Rectoverb 25 or Electra Dyne. No humbuster cables.

Maybe it’s something to do with the particular loop in the Runt 50?
Click to expand...
I had considered that. However, until trying the FM3 in this manner, I had run an entire pedal board with this amp, doing effects in front and through the loop, with no issues, and no noise. My thought here is that if it were the amplifier, it would happen in both circumstances. I could however, be wrong.
 
SinglecutGuy said:
I had considered that. However, until trying the FM3 in this manner, I had run an entire pedal board with this amp, doing effects in front and through the loop, with no issues, and no noise. My thought here is that if it were the amplifier, it would happen in both circumstances. I could however, be wrong.
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Did your previous board have an isolated power supply for the pedals? Are you plugging the FM3 and amp into the same outlet?
 
Are you using USB at the same time? I'm running my FM3 into a 6505+ combo using 4CM, I get crazy loud static if I use USB at the same time.
 
rossipedia said:
Are you using USB at the same time? I'm running my FM3 into a 6505+ combo using 4CM, I get crazy loud static if I use USB at the same time.
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I tried disconnecting the USB and while it did remove a noise for which I already accounted, it did not eliminate the hiss/white noise issue I'm experiencing.
 
SinglecutGuy said:
I tried disconnecting the USB and while it did remove a noise for which I already accounted, it did not eliminate the hiss/white noise issue I'm experiencing.
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I have the same issue with the USB noise. On my 4CM AX-8 I just leave it unplugged until I need to make some changes. On my AXE-III I have to get a USB isolator to kill the noise since I need to have that plugged in most of the time.
 
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