I was thinking of building a phono pre using the DAC21 tube.
It is a DHT triode with low current 1.5 V filaments ( batteries ?)
It has only mu=20 and works with 120 V or less on anode.
Seams to have low distortion and low noise.
How are you ?
The gain is low for a phono stage.
The correct is use a triode with high gain, or you will need three stages for obtain the need amplification.