Post boost varies?

M

McGurk

Member
I have been noticing significantly different volume shifts when I use a 3db post amp boost, depending on the amp I'm using. The Friedman Smallbox, for example, barely has its output volume boosted, while the Dual Rectifier has a huge bump in volume. Why is there a significant difference between boost amounts depending on the amp model? Is it related to one of the amp's parameters?

I thought maybe it had to do with the PEQ block I was adding the db in, but it had the same effect when trying it with a couple other blocks too. Thank you for your collective wisdom!
 
FractalAudio said:
No idea how we're supposed to tell from that preset. Neither amp is the aforementioned amps in your OP and there's only 1dB of gain after the amps.
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The amps I'm experiencing it with are on Amp 2. I'm using each channel of the amp blocks. PEQ 1 is what I'm using for a boost, but I'm using a control switch to boost/cut some frequencies. I just posted the preset I'm using, did I do something wrong?

EDIT: I see now that while I was experimenting with boosting from different blocks, I left the 3db boost in the multiplexer block. Still controlled by control switch 1
 
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McGurk said:
The amps I'm experiencing it with are on Amp 2. I'm using each channel of the amp blocks. PEQ 1 is what I'm using for a boost, but I'm using a control switch to boost/cut some frequencies. I just posted the preset I'm using, did I do something wrong?

EDIT: I see now that while I was experimenting with boosting from different blocks, I left the 3db boost in the multiplexer block. Still controlled by control switch 1
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A 3dB boost will increase the signal by 3dB. How much louder you perceive that as depends on a number of factors, especially volume.
 
FractalAudio said:
A 3dB boost will increase the signal by 3dB. How much louder you perceive that as depends on a number of factors, especially volume.
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Based on his EDIT comment, I think he found the problem... It was an extra 3dB from another block, so he was getting 6dB when expecting 3dB.

Assuming I'm reading it right, of course ;)

Edit:
Based on the OP's reply I wasn't reading it right :eek:
 
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FractalAudio said:
A 3dB boost will increase the signal by 3dB. How much louder you perceive that as depends on a number of factors, especially volume.
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I was going on the output readings from the preset leveling.

While I can't explain this behavior, I did notice that the master volume was much lower on the Recto. I brought it up to similar levels as the other 3 amps, releveled the output volumes using the preset leveler tool, and that cut down on the difference some. It's still reading as a couple db's of a difference between the Recto and the others.

unix-guy said:
Based on his EDIT comment, I think he found the problem... It was an extra 3dB from another block, so he was getting 6dB when expecting 3dB.

Assuming I'm reading it right, of course ;)
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No, sorry, I'm not communicating very clearly. I just noticed that I moved the db boost to another block, and that's why the Fractal guy helping me out didn't see the boost in my preset. The issue is a noticeably bigger db boost on my recto amp compared to the Dumble, Smallbox, and HBE. The master volume thing I mentioned before has cut it down.

Thanks for the help on this. The frequencies I cut and boost in my PEQ may also play into the perceived volume and/or output reading, as cutting and boosting those frequencies can have a different outcome on amps with different eq curves. Even so, when I just run a null filter with a db boost, there's still a difference.

EDIT: I created a new preset, copied over just the amp and cab block. Then I used a null filter for a boost. The problem was gone. It must have something to do with that preset. I'll keep trying to figure it out.
 
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McGurk said:
I did notice that the master volume was much lower on the Recto.
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Adjusting the master volume will help with volume but it also affects the overall sound of the amp too. The Amp block’s level control will adjust the volume without changing the tone.

FractalAudio said:
Master Volume:
The Master Volume (MV) controls how much signal level is sent to the power amp. Many vintage amps have no MV control and the power amp runs "wide open". Modern amps often get their distortion from the preamp and the Master Volume then allows the user to control the volume of the amp.

The Master Volume in the Axe-Fx II, as well as on real amps, is probably the singular most powerful control in the amp block. As the Master Volume is increased the virtual power amp begins to distort. The virtual power amp also begins to sag and all sorts of beautiful magic occurs. The tone becomes more focused, the dynamic response changes, the note attack is accentuated, etc.
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Patzag said:
just so you know, that “Fractal guy” is Cliff Chase, owner of FAS and designer of all Fractal Products.
Rare to see the owner of a company take intimate interest in the well-being of his clients.
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Whoa, that is amazing..!
 
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