Latest project, 12au7 and tda7294 hybrid

[nigel wright]

SRPP front end with chip amp power amp.

 

[audioguru]

I wonder how many times you will need to replace the vacuum tube.
Why use an old vacuum tube when a modern audio opamp sounds perfect and probably will never need to be replaced?
Oh, you want the even harmonic distortion produced by the vacuum tube?
For an electric geetar?

 

[nigel wright]

I like the sound of the valve, it adds warmth and detail to the sound.
Yes it distorts but good distortion.

Front end valve circuits like that are very light on the valve. Valve will probably last 10 years +
I use it for guitar and playing music through.
Sounds good either way.

 

[dr pepper]

Does the triode operate independently or is it included in a feedback loop with the tda o/p chip?

 

[nigel wright]

It operates independently.

 

[dr pepper]

A while back I wondered how good it would sound to have a tube front end and a monolithic amp power driver, and have the tube clip before the power amp, putting attenuator between the tube and the power amps would probably do a similar thing.
I was thinking something more for guitarists, for music you want low distortion.
Are you running the heater from one of the amp rails?

 

[nigel wright]

Are you running the heater from one of the amp rails?

Yes it only takes 150mA with the heaters in series.

 

[dr pepper]

Excellent.
My idea was going to use a nuvistor, back in the 90's they were around, an 12ax7 is easier to get now, or should I say ECC83

 

[schmitt trigger]

What is your plate voltage?

 

[schmitt trigger]

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