Phono Preamplifiers

Similar in name only to the original VIDA [HFN Jul '13], the VIDA Prima employs a far simpler, part-active (low frequency)/part-passive (high frequency) RIAA network. The headline differences in performance between the two are as follows: the costlier Vida offers superior input overload margins, a higher output and lower noise via MC, while the VIDA Prima trades this for a wider MM S/N ratio, a much flatter and extended HF response and lower overall distortion. Talking of distortion, this is indeed exceptionally low at ~0.0002% through the midrange, increasing slightly to ~0.001% at the bass/treble frequency extremes [Graph 2, below]. In practice this is of academic interest only as the typical pick-up's distortion will be 1000x higher (re. 5cm/sec).

Its equalised response is also comfortably beyond that of any pick-up, albeit very slightly 'flatter' on the left than right channel, at ±0.4dB from 100Hz-100kHz and with a subsonic filter of –0.5dB/20Hz down to –6dB/4Hz [see Graph 1, above]. The output impedance is usefully low at 45ohm through mid and treble, increasing to 100ohm/75Hz and 715ohm/20Hz [blue infill, Graph 1]. In its MM setting, the VIDA Prima offers +40.5dB gain (47kohm loading) and a generous 90.5dB A-wtd S/N ratio.

So this is a very quiet MM stage with an input overload margin of 89mV – this represents a headroom of +25dB to accommodate the wildest of vinyl grooves (re. 5mV at 1kHz/5cm/sec). The MC input includes an additional +23.9dB, realising a total gain of +64.4dB, but the A-wtd S/N ratio of 71.3dB is slightly reduced (re. 500µV) and the 5.6mV overload margin is less generous. With a headroom of +21dB (or +19.4dB re. its 0.6mV sensitivity), the VIDA Prima's MC input is best suited to medium- rather than high- or low-output MCs. PM