How calculate GAIN of each step of switch GREEN PRE

I'm planning on modding the values of the resistors on the LORLIN 11 position Switch of the GREEN PREAMP, how calculate GAIN of each step of switch GREEN PRE.

This is because if find it goes to fast in HIGHER GAIN and i want more control to record my GUITAR CAB (I know with high volume into a dinamic Mic it will go up to easy, so this is what I want, no to easy into saturation)

Richon said:

I'm planning on modding the values of the resistors on the LORLIN 11 position Switch of the GREEN PREAMP, how calculate GAIN of each step of switch GREEN PRE.

This is because if find it goes to fast in HIGHER GAIN and i want more control to record my GUITAR CAB (I know with high volume into a dinamic Mic it will go up to easy, so this is what I want, no to easy into saturation)

Click to expand...

To prevent an overload of the input stage, you might consider a pad in front, but the green will not saturate that easy.

Voltage gain of the variable part (there are 2 other stages with fixed gain (diff.amp IC2a at -3.52dB and inverter IC2b adding +6.02dB)
is calculated Av=(R6+R7+Rvar)/Rvar , same as Av=1+((R6+R7)/Rvar) if you like it better
with feedback resistors R6 and R7=2k2 each and
shunt arm Rvar=R33+R32+...+R22, depending on switch position varying between 1R5 up to 154,131R6
(have a look at the schematic and add up the values of these resistors in series)
giving a voltage gain varying between 1.029 up to 2,934.3.
Make this voltage gain a dB reading by LOG10(voltage gain)*20, giving +0.24dB up to 69.35dB.
If you want other gain setting steps, just calculate backwards.