The Honorable Tube Mic & Instrument Preamplifier

Built for Jonathan Meacock

This is one of those projects where the case simply fits the re-purposed application perfectly.  The circuit is a modification of one Rerun has been building for awhile now.  The first stage uses an EF86 (or the Russian equivalent in this case) which can be switched between pentode or triode function-- the Wave Form function.  While in triode mode (sine wave), the EF86 is a very linear medium gain stage whereas in pentode mode (square wave) gain increases thereby adding more distortion.  After this, there is a gain control: Amplitude which feeds into a low gain, high current double triode, the Russian 6N6P.  

From here the signal goes to the Band switch which selects between three different types of Tilt EQ (standard flat, mid hump and mid cut) and bypass.  The large, precise Frequency control determines the resulting sound of the EQ.  Finally, there are two switches for -20dB pad and +48V Phantom power.
The newly realised circuit gives a great thick sound with attendant boost in the lower mid range; and the EQ offers a lot of flexibility to adjust the tone on the fly without detracting from the original signal too much.  Fully balanced in and out with around 60dB overall gain, external power supply and a very compact case make the Honorable preamp a fun and practical tool in the studio.