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Grounded Grid Preamp High Gain Mod

The preamp as supplied has more than enough gain for the vast majority of applications.  There are some special applications where some users have requested more gain.  By just changing out a few resistors and the tubes, the gain can be easily increased to 30 dB. 

Replace R5 and R6 in the kit (or R8 and R12 from Audio Reality) with 1K resistors.

Replace R3 and R4 in the kit (or R10 and R14 from Audio Reality) with 3K resistors.

Replace all three tubes with 12AT7 tubes.

That's all there is to it!

This mod is not recommended unless the additional gain is needed.  If you're not sure that you need the additional gain, then you don't need the mod because you would know if there wasn't enough gain.