The nice thing about DIY is that you can adapt it to your exact needs. This even goes for the gain on the Muffsy Phono Preamp.

Click this link for more details on the gain stages.

Here's more information on considerations when choosing gain.

The variable gain in this circuit is set by the switches on the right hand side named "GAIN-L" and "GAIN-R". They choose one of the 150R and 300R or connects them in parallel.

The switches must be set the same for both channels, and these are the standard gain options:

• Switches 1 and 2 set to ON: 44 dB
• Switch 1 set to ON: 40 dB
• Switch 2 set to ON: 36 dB

By changing these two resistors, you can get other gain levels.

This is what you get by replacing them with 120R and 220R:

• Switches 1 and 2 set to ON: 46 dB
• Switch 1 set to ON: 42 dB
• Switch 2 set to ON: 38 dB

If you replace the 150R resistor with a 100R one, you get these gain options:

• Switches 1 and 2 set to ON: 48 dB
• Switch 1 set to ON: 44 dB
• Switch 2 set to ON: 36 dB

Things to note:

• You must always set at least one of the switches to on.
• The last example gives the highest recommended gain, any higher and you may get noticeable noise.

Resources for calculating gain:

• The first gain stage is set to 31 dB
• The RIAA filter has an 18 dB attenuation
• Total gain will be second gain stage + 13 dB
  
  
• Non-inverting opamp gain calculator
• Parallel resistor calculator