bea
AmBASSador of the F Clef
This will hopefully turn into a usable amp. Or possibly and intended, small all-tube bass combo. Ingredients: the rests of two amps and a technical concept i have started last winter.
The chassis has been taken from an old Dynacord amp from the 70s. More or less the only usable component of that poor amp (well, there is actually also a headshell which would qualify first an forever for playing punk...).
The power supply and the output transformer have been taken from a kit - 15W from EL84 in push pull. My first attempts with tubes, i never got it working and decided to start with something simpler.
The power stage: my own design using 6L6GCs with fixed bias and a cathodyne phase splitter with directly coupled gain stage. LTSpice tells me something of an output power of about 20 W clean.
The preamp section: there will be two fully independent channels. Maybe the input stage i designed for my G-2000, maybe something a bit more elaborate.
The speaker: some substitute for the EV12L, maybe the Oberton 12L/300 or the Eminence Delta 12A, in a vented enclosure equivalently to the TL806 or maybe slightly larger. Maybe i'll design a suitable combo, but i am a bit afraid that even that would already turn out too heavy.
The power supply must be extended a bit in order to provide the bias voltage and also a larger anode voltage than in the kit.
and here a sketch of the schematics of the power stage.
The chassis has been taken from an old Dynacord amp from the 70s. More or less the only usable component of that poor amp (well, there is actually also a headshell which would qualify first an forever for playing punk...).
The power supply and the output transformer have been taken from a kit - 15W from EL84 in push pull. My first attempts with tubes, i never got it working and decided to start with something simpler.
The power stage: my own design using 6L6GCs with fixed bias and a cathodyne phase splitter with directly coupled gain stage. LTSpice tells me something of an output power of about 20 W clean.
The preamp section: there will be two fully independent channels. Maybe the input stage i designed for my G-2000, maybe something a bit more elaborate.
The speaker: some substitute for the EV12L, maybe the Oberton 12L/300 or the Eminence Delta 12A, in a vented enclosure equivalently to the TL806 or maybe slightly larger. Maybe i'll design a suitable combo, but i am a bit afraid that even that would already turn out too heavy.
The power supply must be extended a bit in order to provide the bias voltage and also a larger anode voltage than in the kit.
and here a sketch of the schematics of the power stage.
