jderimig,
I`d keep the design as is, well done!
Rod Coleman,
the differential to SE function is not mandatory, you don`t have to utilise both outputs.
I`d keep the design as is, well done!
The DAC makes an excellent splitter, and better still, the differential to SE function - which is usually done with opamps on the DAC board - is performed by the output transformer.
Rod Coleman,
the differential to SE function is not mandatory, you don`t have to utilise both outputs.
Because you can so easily bring the input valves' cathode current from the available bias supply, you might as well do that. Doesn't have to be an active CCS, can be just a resistor.
This makes the input differential, so minimizes common-mode stuff in the following stage(s). Also helps maintain signal balance for power supply immunity. Free and easy.
YOS,
Chris
This makes the input differential, so minimizes common-mode stuff in the following stage(s). Also helps maintain signal balance for power supply immunity. Free and easy.
YOS,
Chris
I built an amp from two single ended tubelab boards to make a PP amp, and driven by a balanced dac without a phase splitter as you described:
Dual Simple SE's in Push Pull w Differential Input
Dual Simple SE's in Push Pull w Differential Input
Review Design - Balanced input 6DQ6 UNSET output stage
Below is my current design. Using 6DQ6 in an UNSET output stage. Idle is about 17W (yes a little high) for a 50W output. Schematic and spice FFT sims attached. Driven by balanced output of DAC. Any modifications suggested?
Below is my current design. Using 6DQ6 in an UNSET output stage. Idle is about 17W (yes a little high) for a 50W output. Schematic and spice FFT sims attached. Driven by balanced output of DAC. Any modifications suggested?
Attachments
Yes I would allow adjustment of the gate voltages to be separate with pots to set the current in each output valve. MOSFETS have a big spread of current which LTspice will not show. You could try ECC88 for first stage.
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I'm not sure but check, V2 has B+Screen but there's B+ and there's Screen so I assume the to are connected but called the same thing?
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