Heater and HT wiring, wired and tested. Output stage, phase splitter and controls in progress.
15th April 2019. The finished items, tested and ready for the case to be built.
Below, the finished matched pair of type 666 all valve amplifiers.
It has been two years since the conception, to design and build. Very satisfying to build from scratch a finished product. The output valves are Russian made 6L6GC from the 60s, the preamp, phase splitter and drivers are 6AX7, (a Russian built ECC83 with twin 3.15 volt heaters instead of twin 6.3 volt). Nice smooth sound in both Ultra Linear and Pentode mode, which is switchable on the rear of the amplifier. The line up is Volume for Lead, Volume for Bass, Treble, Middle and Bass with Switchable Treble Boost on both inputs, Master Volume control and a Slope control for that extra little bit. The power meter gives a relative reading of the power leaving the amplifier. The amplifier draws 45 Watts in standby and 92 Watts in power on mode up to around 190 Watts depending on the power demanded from the amplifier. It boasts a Neutrik three pole 20Amp power connector and a Neutrik 7.5 Ohm (8 Ohm) speaker connector, (1+ and 1- are the poles used, as in standard 4 pole connectors) and a standard 1/4" jack socket for 15 Ohm (16 Ohm) speakers. This amplifier can use either four 6L6GC (5881) or two KT88 (6550) valves.
Cabinet making now. Covering and strengthening batons, for the case, ordered along with corners, feet and leather handles.