Discussion on QC Input Gain

Quad Cortex
1

Hello everyone, I have a question to ask. What is the relationship between the input gain on the I/O page of QC and the input gain at the beginning of the link in1header? I kept both input gains at zero, but the sound is not correct. My usage method is to use the input gain of -6db on the I/O page and the input gain of+3db in the link header module to make the sound feel correct. I don’t know if everyone is using it the same way. The guitar I am using is 7string, a passive pickup, and the model is bkp jug. Thank you

2

I simply set the input gain in the global settings, so that the guitar that I’m using does not clip. I do not touch any of the preset input gain at all. Most of the volume/gain based adjustments at that point come from balancing output volumes so that they hit around -12db when strumming my hardest. I control this via the amp block volume parameter.

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3

I just set the gain in the Global I/O for the Input port I am using by looking at the bar and doing my best to make it sound as high as possible but without clipping.

1 Like
4

I/O In Level gain:

You set it properly for each instrument you plug to the QC: max of the green zone. It will remain the same for all the presets.

In1 level:

I never change it and keep it by default.

Block’s levels:

For EACH block in the grid, adjust properly In Gain AND Out volume: On or Off, this block must not change the final level; just provides its effect, but keeps the incoming level.

Then, the final output level should be approx at Line Level, perfect to enter the Mixer via Line Input connector.

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5

That makes sense. A 7 string with see what high output pickups like that can make the input clip and then the amp models won’t respond the right way. There isn’t a rule about how to set the gain, other than making sure it’s not clipping but high enough where the tone doesn’t feel strange

6

I think you have the right approach. With I/O input gain at 0dB and the input block level at 0dB you are not adding or removing any gain, and the other blocks in your preset will be seeing the levels they were designed for. You’re then gain staging in the blocks themselves, similar to how you would use the pedals and amps these blocks are modeling.

Any change to I/O gain can be balanced with the inverse gain in the input block to maintain unity gain which ensures all the blocks are seeing the same levels and there’s no change in your tone. You’d do this to adjust for hot or weak pickups to avoid clipping the input A2D converters.

You can of course use I/O and input block gain for a clean boost if that’s your intent. But I avoid that so that the other blocks have predictable behavior. That is, I’d use a volume block to make it obvious I’m adding gain for some reason - like to balance the same patch between single and double coil pickups.

Note also that the I/O input gain is global and not saved with a patch while the input block gain is. So changing the I/O input gain changes the gain staging for all patches, probably not you intent.