[SOLVED] Please help. Am I overlooking something with 4CM (Diezel VH4 and FM3)?

sprada

sprada

Inspired
Hi everyone.

After many years not using Fractal products I decided to buy an FM3 to use with 4 cable method with my Diezel VH4.
I was not expecting any problems since the Diezel has a very high quality effects loop (has actually 4!) and I've used 4CM with a Gigrig g3 and "real" pedals without any problem.
It was very silent.

Just tried today the FM3 and it's simply not usable.
It's so so noisy.

I'm kind of hoping I've messed something up.

Rundown of the setup:

FM3 Audio Setup:
Output 1 = +4db (-10db seems way too silent). Physical knob is at around 12 o'clock (less than that and I'm losing volume)
Output 2 = Set to unity gain. Boost/pad set to 18db (helps a little. And it is not clipping). Physical knob is maxed out.
Input 1 and 2 have pad at 0db.

1698874017504.png

I'm using the exact same setup as suggested in the manual.
Cables are very high quality and were custom built to specs by audiocables.eu (humbuster is being used as suggested)

Everything is connected to the same plug.

I've tried a lot of things and nothing is really helping.
Lowering Output 1 helps but having the knob at less than at 12 o'clock I'm definitely losing volume.

Just to have an idea.
With the guitar connected and volume completely rolled off on the Diezel channel 2
4CM I get 74db
Guitar straight to amp I get 55db!!!

I don't know what else to do.
Any suggestions?
Am I doing something wrong?
 
Last edited:
I having a similar problem with my Friedman IR-X
It is soo noisy in 4 cable.

I go into fm3 input 1 -> fm3 output 2 -> Friedman input -> Friedman output->fm3 input 2 then into post effects and monitoring by headphones.

Setting the output 2 boost/pad to 12 or 18 does help but then I'm clipping output 2 so have to turn the volume down which then feels I'm not hitting the preamp at the right level and sounds weak.
 
Just to add to this - I've been playing around with this and if I go fm3 input -> output 2 spdif into my Benchmark DAC xlr out-> Friedman IR-X input and then back into my Fm3 return this works really well with excellent output and no noise.

It seems an unnecessary step having to use an external DAC but it seems the fx send isn't great.
 
sprada said:
Hi everyone.

After many years not using Fractal products I decided to buy an FM3 to use with 4 cable method with my Diezel VH4.
I was not expecting any problems since the Diezel has a very high quality effects loop (has actually 4!) and I've used 4CM with a Gigrig g3 and "real" pedals without any problem.
It was very silent.

Just tried today the FM3 and it's simply not usable.
It's so so noisy.

I'm kind of hoping I've messed something up.

Rundown of the setup:

FM3 Audio Setup:
Output 1 = +4db (-10db seems way too silent). Physical knob is at around 12 o'clock (less than that and I'm losing volume)
Output 2 = Set to unity gain. Boost/pad set to 18db (helps a little. And it is not clipping). Physical knob is maxed out.
Input 1 and 2 have pad at 0db.

View attachment 129030

I'm using the exact same setup as suggested in the manual.
Cables are very high quality and were custom built to specs by audiocables.eu (humbuster is being used as suggested)

Everything is connected to the same plug.

I've tried a lot of things and nothing is really helping.
Lowering Output 1 helps but having the knob at less than at 12 o'clock I'm definitely losing volume.

Just to have an idea.
With the guitar connected and volume completely rolled off on the Diezel channel 2
4CM I get 74db
Guitar straight to amp I get 55db!!!

I don't know what else to do.
Any suggestions?
Am I doing something wrong?
Click to expand...

A few questions:

1. How are you connecting between the the FM3 and the amp? For example, you say output1 is set to +4dB, but that doesn’t make sense for going into the front of the amp (which is optimized for instrument level, not line level). But perhaps you’re going from output2 to the input of the amp?

2. What type of cable are you using at each connection - for example, output1 is a balanced XLR while the amp connections are, presumably, all unbalanced TS - how are you converting from balanced to unbalanced?

3. Can you post a photo of the preset?

4. What type of noise are you getting? Hiss, hum, buzz, crackling? All are different and may suggest a different approach to troubleshooting.

5. How does it sound if you remove the cables from the FX send and return - i.e., so you’re just hearing guitar->FM3->guitar amp? This may help isolate whether the issue is before or after the amp’s preamp.

FWIW, my approach when interfacing with an amp is to start with everything at approximately unity gain - for example, the level hitting the input of the amp should be about the same as the unboosted guitar signal. You may of course want to boost the front end of the amp, but i suggested getting it set up and working well unboosted, and then you can try adding boosts.

Same for the FX loop - get it set up so that with no FX blocks active in the FM3 between the FX send and the FX return the signal is the same level as if you remove everything from the amp’s loop - in effect, the FM3 is just passing the signal through with no changes. Once that is working well, then start adding FX.
 
One more thing - which loop of the Diezel are you using? I would expect that only the serial loop (not the 4 channel inserts, not the parallel loop) will accomplish what you want with 4cm.
 
Hi,
Rumbletone said:
1. How are you connecting between the the FM3 and the amp? For example, you say output1 is set to +4dB, but that doesn’t make sense for going into the front of the amp (which is optimized for instrument level, not line level). But perhaps you’re going from output2 to the input of the amp?
Click to expand...
It's output 2 to front of the amp.
I'm following the manual.

1699004586523.png
Rumbletone said:
2. What type of cable are you using at each connection - for example, output1 is a balanced XLR while the amp connections are, presumably, all unbalanced TS - how are you converting from balanced to unbalanced?
Click to expand...
I'm using what is suggested in the manual.
Humbuster from out 2 to amp main input.
TS from input 2L to amp FX send
XLR from output 1L to TS -> amp fx return (XLR pin 2 to TS tip. XLR pins 1 and 3 to TS Sleeve)

Rumbletone said:
3. Can you post a photo of the preset?
Click to expand...
There's literally nothing added (it does work properly when adding effects pre or post). Just the shunts to make the connections (in1->Out2 || In2->Out1).

Rumbletone said:
4. What type of noise are you getting? Hiss, hum, buzz, crackling? All are different and may suggest a different approach to troubleshooting.
Click to expand...
Mostly Hum and a bit more hiss than usual. it get's worse if I'm using a gain channel on the amp. The hiss 100% get's worse.

Rumbletone said:
5. How does it sound if you remove the cables from the FX send and return - i.e., so you’re just hearing guitar->FM3->guitar amp? This may help isolate whether the issue is before or after the amp’s preamp.
Click to expand...
Haven't tried using the FM3 just as a pre-amp. I'll do this in the next couple of days.

Regarding levels.

Most of troubleshooting time was spent on making sure that levels were ok.
I found that Out1 at +4db and the knob at 12 o'clock seems to be unity gain for me.
With out1 at -10db I need to set out1 knob at 3 0'clock and that clips out 1.
Out 2 is set to unity gain and the knob is maxed out.

I'm using the VH4 main effects loop in serial mode.

I have just ordered a Morley Humno to see if it helps with the hum.
 
Last edited:
sprada said:
Hi,

It's output 2 to front of the amp.
I'm following the manual.

View attachment 129134

I'm using what is suggested in the manual.
Humbuster from out 2 to amp main input.
TS from input 2L to amp FX send
XLR from output 1L to TS -> amp fx return (XLR pin 2 to TS tip. XLR pins 1 and 3 to TS Sleeve)


There's literally nothing added (it does work properly when adding effects pre or post). Just the shunts to make the connections (in1->Out2 || In2->Out1).


Mostly Hum and a bit more hiss than usual. it get's worse if I'm using a gain channel on the amp. The hiss 100% get's worse.


Haven't tried using the FM3 just as a pre-amp. I'll do this in the next couple of days.

Regarding levels.

Most of troubleshooting time was spent on making sure than levels were ok.
I found that Out1 at +4db and the knob at 12 o'clock seems to be unity gain for me.
With out1 at -10db I need to set out1 knob at 3 0'clock and that clips out 1.
Out 2 is set to unity gain and the knob is maxed out.

I'm using the VH4 main effects loop in serial mode.

I have just order a Morley Humno to see if it helps with the hum.
Click to expand...

Thanks. The only thing that seems potentially odd is that the outputs need to be so high for unity gain.

Re the hum, what happens if you press the ground lift switch on the FM3? Does it affect the hum level (if not eliminate it)? In any event, it may be a ground loop and a device like the Morley may help.
I always have a transformer isolation device available to try to eliminate hum is these situations so it’s probably work having one in your arsenal regardless.
 
Thanks.
I think out2 is designed for unity gain at fully clockwise.
Yeah it really sounds mainly like ground loop + a bit of hiss.
Ground lift does not help :(
 
Use a humbuster cable from the out 2 of your FM3 into the input of your amp. Makes a big difference. Channel 3 of my Bogner XTC is unusable with my Axe 3 in 4CM, without it. Also, USB connections from your FM3 to your PC or MAC maybe culprits of some noise in this config as well.
 
Satch4u3 said:
Use a humbuster cable from the out 2 of your FM3 into the input of your amp. Makes a big difference. Channel 3 of my Bogner XTC is unusable with my Axe 3 in 4CM, without it. Also, USB connections from your FM3 to your PC or MAC maybe culprits of some noise in this config as well.
Click to expand...
The poster is using a humbuster cable.
 
I am using an humbuster cable.
Just tested disconnecting FM3 from PC.
Made no difference unfortunately :(
 
Oh I missed that part. Try another humbuster cable maybe. However, the Morley Humno you have order might be your ticket if it's a ground loop issue. Post your preset so we can have a look. Also, does the noise go away at all when you plug your guitar straight in to your amp, just leaving the post effects in the chain? The front end connections were my issue.
 
I have just tested the Humno. It does get rid of most of the hum.
However I think I've misevaluated the noise.
Most of it was actually Hiss (when using the VH4 clean channel with hum gone it's pretty silent now)
I believe the hiss comes from the OUT1 volume. It needs to be quite high to maintain unity.

Interestingly If I'm still connected using 4CM and bypass the amps pre amp and use the FM3 as pre-amp it's dead silent (preset= IN1 ->Amp Block -> OUT1).

I'm really a loss here
 
sprada said:
I have just tested the Humno. It does get rid of most of the hum.
However I think I've misevaluated the noise.
Most of it was actually Hiss (when using the VH4 clean channel with hum gone it's pretty silent now)
I believe the hiss comes from the OUT1 volume. It needs to be quite high to maintain unity.

Interestingly If I'm still connected using 4CM and bypass the amps pre amp and use the FM3 as pre-amp it's dead silent (preset= IN1 ->Amp Block -> OUT1).

I'm really a loss here
Click to expand...
I've been working offline with @eloygperez in relation to this thread https://forum.fractalaudio.com/thre...with-4cm-axe-fx-iii-5150.199177/#post-2479173

They will be posting an update soon on this thread - but what you are experiencing I don't think is uncommon - If i use the output 2 into my preamp then I get horrendous hiss but when I went spdif out into a dedicated Digital to Audio converter into my preamp then it is a lot quieter.

I'm not sure why this occurs it might be an impedance thing - but it is also worth noting that on the facebook group for my preamp people have experienced the hiss with other devices such as Helix.
 
Thanks.
I'm following that thread now.
I wonder if this is an impedance matching type problem and that's why a DI box helps.
Oh god, another device plus another cable.
5CM cable method.
 
In my situation, I get a manageable noise when reamping DI tracks through my real amp (using a MW1 di/reamp box). Adding the Axe FX III before the amp (for using drive blocks, ect) turns into noise problems using the Axe Out 3/4 into the amp. Let's see if that humbuster cable solves my problem...
Unexpectedly the longest chain (receiving my DI track in Axe input 1, sending it via spdif to my external converters, and from converters analog out into my amp) made the least noise. But it seems unnecessary to use a chain like that, honestly...
 
sprada said:
I have just tested the Humno. It does get rid of most of the hum.
However I think I've misevaluated the noise.
Most of it was actually Hiss (when using the VH4 clean channel with hum gone it's pretty silent now)
I believe the hiss comes from the OUT1 volume. It needs to be quite high to maintain unity.

Interestingly If I'm still connected using 4CM and bypass the amps pre amp and use the FM3 as pre-amp it's dead silent (preset= IN1 ->Amp Block -> OUT1).

I'm really a loss here
Click to expand...

How is the noise if you connect straight from the guitar to the input of the amp’s preamp? That may help determine whether the source of the noise is the FM3->preamp input vs elsewhere.
 
Rumbletone said:
How is the noise if you connect straight from the guitar to the input of the amp’s preamp? That may help determine whether the source of the noise is the FM3->preamp input vs elsewhere.
Click to expand...
Connected directly to the amp? It's pretty much silent.
On Channel 2 it's around 59 dbs at gig level.
With 4CM and FM3 at the same level is around 80dbs (with the Morley Humno went from around 80 dbs to around 73/74 dbs)
(these measurments are done with the guitar volume roled off.)
 
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