Vermes
Advanced Member level 4
This is a construction of two-channel 50W full tube amplifier in a classic style with separate inputs for channels without the possibility to switch them while playing. It was processed few times before it looked like it is presented in the pictures. Ladder system is used with ground bus, what causes placing the double-triode preamplifier's tube in other place than it was before the modification. The old hole was covered with aluminum plate. The chassis is equipped with seven holes for potentiometers on the front panel and 5 for jack sockets (3 in front of potentiometers and 2 behind them). A typical preamplifier has 5 potentiometers (gain, three-point eq and volume), so there are 2 left. Another independent ultra clear channel on EF86 was added. It has Tone and Volume regulators. Classic high and low inputs of different sensitivity were added in triode channel, as there were three places for jack sockets in front of potentiometers. Channel on EF86 has a single input of high type. Cold cathode tubes were inserted in holes which were once used for output of preamplifier and input of the power amplifier. Those tubes indicate switching the mains and anode. Output of triode preamplifier and input of the power amplifier were moved to the rear panel into the holes which initially acted as outputs for speakers. The construction uses an inverter similar to Marshall or Orange devices. It is a paraphase inverter based on cathodic coupled two triodes. In double-triode channel on 6N2P-EV corrector was moved to the second level, but it is still a Master construction with volume regulator in front of the inverter. Levels are typical for Fender.
Pictures:
Link to original thread - Boomerang - dwukanałowy gitarowiec 50W full lampa.