Vermes
Advanced Member level 4
It is a full tube, two channel micro-amplifier in „flat” style – its 1U height is typical for preamplifiers adapted to 19”. This amplifier is even shorter than a typical 19” housing – it is 43,5cm long. The device has its own rubber feet and can operate as a separate amplifier. Clear channel is based on a single EF86 – like in Matchless, with a typical control based on six-positions switch, which is used to change the value of separation capacity.
Distortion channel is a four hi-gain based on a modded Mesa DR, but without the cathode follower. A typical Mesa equalizer was equipped with twice larger resistor (100k instead of 47k) in order to better cooperate with the stage. That channel was made on two 6N2P-EV. Power amplifier comes from FireFly. It is a simple inverter on ECC82 with cathode coupling, in which windings of output transformer were used instead of anode resistors.
Supply transformer consists of a small 30W toroid (250V/6,3V/12V/9V). That transformer provides all voltages necessary in the circuit (anode, glow, supply of the channel switching system and cabsim supply). Glow of all tubes is done from symmetrized AC voltage to the ground by two 100R resistors. Output is a correctly applied mains transformer TS3/3.
Housing was removed from an old photomodem Lanex TM60.
Cabsim circuit can be found at: LINK. It cooperates not with the preamplifier but load at the power amplifier (speaker or 8R2/5W resistor). There is a speaker output, linear (adjustable) output, cabsim output (adjustable), power amplifier input and preamplifier output on the rear panel.
Link to original thread - Mikrowzmacniacz gitarowy full lampa - UNHOLY
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