Pre/Power Amplifiers

Introduced by RCA in 1959, the nuvistor's brief was simple – tackle all that was deficient in glass-bodied vacuum tubes. By improving on reliability, size, microphony, operating performance (noise, gain, linearity and PSU requirements) and consistency between manufacturing batches, the miniature, metal-bodied nuvistor was rolled out to great fanfare in RCA's TV and radio sets. As innovations go, the nuvistor represented a step change in the evolution of vacuum 'tubes', but its timing was... unfortunate. Germanium transistors were in the ascendent and once their own reliability/performance issues were addressed by the development of silicon devices, the nuvistor, aside from a few very niche applications, was doomed.

Readers may remember the tale of the Russian MiG-25 – flown to Japan in 1976 by a defecting pilot – that hosted EMP-proof nuvistors in its critical flight systems. Conrad-Johnson had a brief flirtation with the miniature technology in its Premier Seven preamp in 1988 but, otherwise, the next time these tiny metal cylinders shook the consciousness of our audiophile world was in the late 1990s when then-owner of Musical Fidelity, Antony Michaelson, acquired a NOS batch. These were deployed in its Nu-Vista Preamplifier [HFN Aug '98] before a similar nuvistor line stage found its way into the company's Nu-Vista 300 amplifier [HFN Jun '99], CD Player [HFN Dec '15] and Nu-Vista 800 [HFN Nov '14], the latter also the inspiration for the four-box PRE/PAS we have here. PM