Why is using the Amp Level Parameter the best method for Gain Staging?

zappafranco

zappafranco

Inspired
I know that you can zoom in at the Amp Block Layout Page to view the VU Meter while Gain Staging with the Amp Level Parameter and that it has been recommended in the manual and in this forum many times that using the Amp Level Parameter is the best way for Gain Staging Presets.

OK, but the Output Block also shows the VU Meter. So why shouldn’t we use the Output Level Block for Gain Staging? Does this introduce more noise or what is the reason?
 
Gain staging implies setting proper level at every point in the signal path.
In your scenario, although your final output level might be fine when set at the Output block, you could be overloading all the blocks inserted after the Amp block (but before the Output block).
 
Also, some of the amp models have a hotter output that others at 0 on the output parameter. So you can’t just set the output in the amp block to zero and get the same relative volume from different amp models.
 
finleysound said:
Gain staging implies setting proper level at every point in the signal path.
In your scenario, although your final output level might be fine when set at the Output block, you could be overloading all the blocks inserted after the Amp block (but before the Output block).
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How can you tell if you're overloading other blocks before the output block?
 
zappafranco said:
I know that you can zoom in at the Amp Block Layout Page to view the VU Meter while Gain Staging with the Amp Level Parameter and that it has been recommended in the manual and in this forum many times that using the Amp Level Parameter is the best way for Gain Staging Presets.

OK, but the Output Block also shows the VU Meter. So why shouldn’t we use the Output Level Block for Gain Staging? Does this introduce more noise or what is the reason?
Click to expand...
because the Amp block is the biggest source of volume/level compared to most other blocks that are Unity Gain in concept. notice that almost all other blocks have the level set to 0 dB - unity, no change - compared to the Amp block (and drive block) where the Gain and many other parameters can drastically change the volume.

amp makes the most level change, makes sense to change level with that. Output block can be used to slightly adjust complex presets if necessary (compressors at the end, etc). but it's best to have things balanced throughout the preset.

i've helped people with presets where the amp block was like +16dB, and the Output and Reverb block was -20dB or something to compensate. i put those blocks back to 0 and adjusted the Amp block to around -12 or so and everything sounded better.
 
I generally set non-amp/drive blocks to 0 and then adjust amplevel so that the final output block set to 0 hits the horizontal line on the output block meter with hard strums. Then I activate drive and adjust drive mix/level to keep the same output level from the previous step. Thirdly, for each fx block I make small level adjustments above/below 0 where needed to keep a consistant volume. Finally after I'm happy with the patch in all variations, I drop the final output block by 6db to ENSURE enough headroom at Axefx output so there is no possibility of output clipping.

Following this method for all patches keeps patches level with each other and within themselves while pushing a descent signal strength to downstream gear with no digital clipping possible regardless of patch/scene or strumming strength.
 
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Once I have the level set properly in the Amp and subsequent blocks, I adjust the overall volume using the Output block. It's not uncommon for me to use a Multiband Comp block after the Amp block, and in that particular case, tweaking the level parameter in the Amp block can affect how hard the signal hits the multiband compressor.
 
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Thank you very much for all the good advice. With regard to Gain Staging I made the following remark in the AXE FX3 Wish List in the thread
"Assignable USB Computer Input sources":

zappafranco said:
More flexible USB Audio Routing would have a lot of advantages. My personal favorite would be the following:
If I haven't overlooked something, right now you get from the AXE via USB to the Computer only the Guitar Signal (dry or wet). But let's say you use the AXE to play guitar and backing tracks at the same time. I am using the following USB Output Mapping for this:
1/2 -> Out1, 3/4 ->Out 2
This enables you to control the volume Out1 (Guitar) and Out2 (Backing Track) with the corresponding Level Knobs which is really very handy.
The only problem is that I can't use a Stand Alone Loudness Software to level the Loudness of the Guitar against the Loudness of the Backing Track, because the 3/4 ->Out 2 Signal can not be send to the computer. It only goes directly out from Out 2 to the mixer, speaker or whatever you are using. I am aware of the fact that the AXE has a VU Meter Page, but I have to admit that my eyes are not the best and those meters are really nice and useful, but it would be great to have the option to assign Out1 and Out2 independently via USB to the metering software of your choice.
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