Musical Fidelity preamp

[Eric Barbour]

>Nuvistas, some sort of mini-valve, with all the inherent advantages of
>valves/tubes and the compactness of trannies. Small metal canisters about
>the size of a BFY33, I think. Pictures can be deceptive. Does anyone know
>more about these wee beasties?

That's "Nuvistor". Introduced by RCA in 1959. All metal and ceramic
tube using indirectly-heated cathode. Intended for RF applications
at VHF and up, which transistors of the time were not capable of.
Used as RF front-end in Fisher and Scott FM tuners and receivers,
later used in audio equipment. Specifically the Ampex MR-70 reel
tape recorder, one of the best all-tube machines ever made. Also
used in condenser microphones and in the Conrad-Johnson PV-3
stereo hi-fi preamp of 1982.

Nuvistors have been out of production since 1988. They will probably
never be made again due to low demand. Musical Fidelity bought a
large stock of NOS Nuvistors, still, I think this was a bad idea. They are
very good little tubes (except for some microphony) and have low
distortion and low noise. A shame--they are likely to be dead products.

See my nuvistor phono stage article in GLASS AUDIO magazine,
4/93 issue.

Eric Barbour
Svetlana Electron Devices
Portola Valley CA USA