4CM clipping Output 2 with Drive block set up as a clean boost

M

marshall2553

Power User
I just got around to trying my FM3 with my real amps using the 4CM. I'm using Out 2 for both outputs to my amp, with row one of the grid containing my pre effects panned left and row two containing my post effects panned right. Out 2L goes to the input of my amp, the amp's effects send goes to In 2L, and Out 2R goes to the amp's effects return. I have the Output 2 level knob cranked to put it at unity gain. This works as expected. I'd like to set the drive block up as a clean boost for the dirty channel of my amp with something like a TS 808 with the drive low and the level on 10. As soon as I engage the drive block, the Out 2 clip LED starts lighting up. Am I doing something wrong or can you really not hit the front of your amp with a clean boost without clipping the FM3's output?
 
I’m guessing your Pre signal chain has something more than unity gain. For example, if you’re running at +8 VU without boost, and you add a 10 dB boost, you’re probably going to clip the output.
 
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Rex said:
Im guessing your Pre signal chain has something more than unity gain. For example, if you’re running at +8 VU without boost, and you add a 10 dB boost, you’re probably going to clip the output.
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My pre is just Input 1 -> Drive -> Output 2. Levels in the input and and output blocks are at 0dB. The level going into the input of my amp also sounds the same as when I just plug my guitar straight into the amp.
 
marshall2553 said:
My pre is just Input 1 -> Drive -> Output 2. Levels in the input and and output blocks are at 0dB. The level going into the input of my amp also sounds the same as when I just plug my guitar straight into the amp.
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What’s the level when you engage your boost?
 
marshall2553 said:
with the drive low and the level on 10.
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with the level on 10 going to an amp block, the level doesn’t increase drastically because the amp block is reacting like a real amp, adding gain and not volume. With no amp block, it makes sense that the output would clip with a big increase in level like that.

Not sure of a way to avoid that. Maybe someone else can think of one.
 
chris said:
with the level on 10 going to an amp block, the level doesn’t increase drastically because the amp block is reacting like a real amp, adding gain and not volume. With no amp block, it makes sense that the output would clip with a big increase in level like that.
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The thng here is that the FM3 has so much internal dynamic range (more than 1400 dB) that it’s pretty much impossible to cause internal clipping. But the OP is clipping the output converter here.

Maybe don’t run the Drive’s output level all the way up to 10. I don’t do that IRL, anyway. :)
 
Rex said:
The thng here is that the FM3 has so much internal dynamic range (more than 1400 dB) that it’s pretty much impossible to cause internal clipping. But the OP is clipping the output converter here.
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Yup. Thought I said that shrug
 
The maximum output level is around +22 dBu and the maximum output of nearly all drive pedals is around +12 dBu so you shouldn't be clipping. Therefore either your boost/pad setting is too high or there is a normalization bug somewhere.
 
FractalAudio said:
The maximum output level is around +22 dBu and the maximum output of nearly all drive pedals is around +12 dBu so you shouldn't be clipping. Therefore either your boost/pad setting is too high or there is a normalization bug somewhere.
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This is likely it. I’m using humbusters but I still have more noise than I’d like, so I messed with the out 2 boost/pad. I’m not at my FM3 and I don’t remember if I ended up with it on 6 or 12 dB. I guess I’ll have to live with a little noise. I seem to remember running into this same issue on the FX8. I plan on primarily using the FM3 direct so it isn’t a big deal, but man does it sound good as a pedalboard replacement with my amps.
 
Bumping this thread. I clip Output 2 at Unity Gain when using the Shimmer Drive as a clean boost. Boost/pad setting is at 0 dB. Output 2 knob all the way clockwise. This shouldn't be possible, right?
 
pipboy90 said:
Bumping this thread. I clip Output 2 at Unity Gain when using the Shimmer Drive as a clean boost. Boost/pad setting is at 0 dB. Output 2 knob all the way clockwise. This shouldn't be possible, right?
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are you clipping the output of the Fractal or the input of whatever it's plugged into? What do the FM3,s output meters show? Does the clipping go away if you reduce the output 2 volume?
 
Rumbletone said:
are you clipping the output of the Fractal or the input of whatever it's plugged into? What do the FM3,s output meters show? Does the clipping go away if you reduce the output 2 volume?
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Yes, I'm clipping Output 2 on the FM3. The meters for Analog Out 2 are peaking at the top of their range and the "Out 2 Clip" light is flashing red on the front of the FM3. The clipping does go away when I turn down the Output 2 volume knob, but then I'm no longer getting Unity gain from my guitar when the Drive block is bypassed. I'm testing this out with the Shimmer drive in particular (with the volume on the pedal maxed).

Can you reproduce this on your FM3?
 
pipboy90 said:
Yes, I'm clipping Output 2 on the FM3. The meters for Analog Out 2 are peaking at the top of their range and the "Out 2 Clip" light is flashing red on the front of the FM3. The clipping does go away when I turn down the Output 2 volume knob, but then I'm no longer getting Unity gain from my guitar when the Drive block is bypassed. I'm testing this out with the Shimmer drive in particular (with the volume on the pedal maxed).

Can you reproduce this on your FM3?
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What else is in the preset’s signal chain (amp etc)? There are so many places that the volume can be attenuated/boosted within individual blocks, plus the global I/O settings, that I think you’d need to replicate all of those settings in order to then test whether the shimmer drive puts it over the top.

That said, I suspect the solution may be to bring all your presets down in level so that your ‘unity gain’ still leaves a huge amount of headroom for boosting. When you are in the ‘preset levelling’ window, where are the meters peaking for your ‘unity gain’ tones?
 
Rumbletone said:
What else is in the preset’s signal chain (amp etc)? There are so many places that the volume can be attenuated/boosted within individual blocks, plus the global I/O settings, that I think you’d need to replicate all of those settings in order to then test whether the shimmer drive puts it over the top.

That said, I suspect the solution may be to bring all your presets down in level so that your ‘unity gain’ still leaves a huge amount of headroom for boosting. When you are in the ‘preset levelling’ window, where are the meters peaking for your ‘unity gain’ tones?
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That's the thing: there's nothing else activated in the chain. It's In -> Drive 1 -> Out 2. No boosts or cuts to the In or Out Blocks. Unity gain. Global I/O settings are at default, no boosting. In the Preset Leveling window, the meters are peaking at -24dB for Unity Gain. Activating the Drive block with the Shimmer Drive Level maxed shows the meters peaking at -11dB, with the Analog Out meters on the FM3 for Output 2 reaching close to max and the Out 2 clip LED lighting up.
 
pipboy90 said:
That's the thing: there's nothing else activated in the chain. It's In -> Drive 1 -> Out 2. No boosts or cuts to the In or Out Blocks. Unity gain. Global I/O settings are at default, no boosting. In the Preset Leveling window, the meters are peaking at -24dB for Unity Gain. Activating the Drive block with the Shimmer Drive Level maxed shows the meters peaking at -11dB, with the Analog Out meters on the FM3 for Output 2 reaching close to max and the Out 2 clip LED lighting up.
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thanks - what is the 'output 2 boost/pad' parameter set to?
 
This actually occurs with the FM9 as well. I use O3 instead of O2 but I do not set O3 all the way clockwise. I have found that volume wise and effects wise there is not too much difference in sound and the noise level is considerably less. So I run my volume for O3 about 1-2 o’clock. Try that with your O2 see if that works. 4cm is not plug play with every head so you actually may not be able to run your unity gain volume at full max without some noise or clipping. That has been my experience.
 
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