Pre-amplifer for magnetic phono pick-up.

[Valvebloke]

Valve preamp for magnetic cartridge is seriously challenging ...

This, I'm afraid.

It can be done though. The quietest circuits I've ever come across used triodes. If you have a stock of them then you may gain a lot by working your way through them until you find a quiet one (or two, if you want stereo and don't want to split a double triode between the channels). Back in the day the criterion only had to be that the noise from the pre-amp was rather less than the surface noise on the record. In the absence of a record the pre-amp can sound quite noisy. But once the stylus touches down the record noise dominates.

It goes without saying of course that circuit design, wiring layout and construction need all to be of the highest quality. The bass boost that the RIAA correction applies will otherwise generate an enormous amount of hum.

VB