Preamp 12AU7 amplifier stage and a HiFi amplifier stage with a TDA7293 and isolated tone control. What do you think?
No, como amplificador de audio, es prácticamente sin distorsión. Creé un circuito de preamplificador de una sola etapa con el ECC82 para alimentarlo con 17 V en las placas. El autor afirma que tiene muy baja distorsión y es mucho más lineal en el rango de frecuencias audibles que otras configuraciones de placas de bajo voltaje.
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Excuse me. No, as an audio amplifier, it's virtually distortion-free. I created a single-stage preamplifier circuit using the ECC82 to power it with 17 V at the boards. The author claims it has very low distortion and is much more linear in the audible frequency range than other low-voltage board configurations.
The suggested (datasheet) input resistor for a TDA7293 is 22K, which is pretty low for such a pre-amp circuit. You may want to add a DC-coupled mosfet follower to help reduce the output impedance. It would be better also to remove the cathode blocking cap, it will give you a better input voltage range, and also reduce distortion a bit.
I have done some simulations, it should work, but Spice tube models are not very good at reproducing low voltage behaviour, so take it with a grain of salt....
I have done some simulations, it should work, but Spice tube models are not very good at reproducing low voltage behaviour, so take it with a grain of salt....
Not sure why 17 volts
When for" low voltage" a TDA7293 would be powered with 30 to 42 volts +/_
So might as well power the tube with that.
With simple constant current sources the tube stage can work rather well at low voltages.
When for" low voltage" a TDA7293 would be powered with 30 to 42 volts +/_
So might as well power the tube with that.
With simple constant current sources the tube stage can work rather well at low voltages.