Compressor makeup gain

Elektron Gear Octatrack
1

Another way-in-the-weeds analysis. I wanted to use the compressor for clean make-up gain after another effect cut the signal quite a bit. I figured that I could keep THRS=127, RAT=0, and MIX=127. Varying GAIN should just increase gain. But by how much?

I looked at it in two ways: I measured it with a null signal and then I started “poking” the DSP code. Here is what I found:

GAIN dB (ideal) dB (measured)
0 0.00 0.0
1 0.13 0.1
2 0.52 0.5
3 1.14 1.1
4 1.93 2.0
5 2.85 2.9
6 3.86 3.9
7 4.92 4.9
8 6.00
9 7.08
10 8.15 8.1
11 9.20
12 10.21 10.2
13 11.20
14 12.15
15 13.07 13.0
16 13.95
17 14.80
18 15.62
19 16.41
20 17.18 17.2
21 17.91
22 18.62
23 19.31
24 19.97
25 20.61 20.6
26 21.23
27 21.83
28 22.41
29 22.98
30 23.53
31 24.06 24.0

Could be useful if you know how much an earler step decreased gain. There is actually about 48 dB of gain on tap, but in my experience things start clipping after 24 dB. If you’re actually using the compressor to compress, you might need that kind of make-up gain.

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2

One place that this came up was using the CUE send. I noticed that setting the GAIN=1 restored the slight signal cut. I’m not sure if it is perfect, but it helped a lot for what I was doing.

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3

And here’s another simple example where I felt like I needed this:

The sample is sine waves and it is going through the bit-reduction effect. As you decrease VOL it really changes the character of the bit reduction. But that cuts the volume. So I mapped the crossfader to cut VOL and increase GAIN on the compressor. It isn’t quite perfect, but basically does what I was hoping to do - evolving timbre without much output level change.

VOL ranges from 0 to -48. GAIN ranges from 0 to 29.

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