Phono Preamplifiers

Following the Nu-Vista Vinyl 2’s lead [HFN Feb ’24], Musical Fidelity’s M8x Vinyl allows for four MM and four MC gain settings, each grouped in 3dB increments. Tested via its balanced inputs and outputs, the +40dB to +49dB MM gain options arrive at +40.4dB, +43.4dB, +45.9dB and +48.9dB, accommodating pick-ups rated between 3.6-9.6mV (re. 1kHz/5cm/sec) to deliver a 1V (0dBV) output. The MC gain options range from +60dB to +69dB (+60.2dB, +63.2dB, +65.7dB and +68.7dB, in practice) and will match moving-coils over a useful 368-976µV spec’d output. Naturally, higher and lower output MCs are still perfectly ‘useable’ at the +60dB and +69dB settings, respectively, thanks to the consistent 71dB A-wtd S/N ratio (re. 500µV input). The MM stage offers a wider 81.0dB (re. 5mV input) – exactly the same as the Nu-Vista Vinyl 2, and despite also being 10-15dB behind the ‘quietest’ phono stages this figure is still beyond the through-groove vinyl noise of the finest turntables.

Distortion remains very low too, falling to 0.002%/1kHz and a lower 0.0003%/20kHz [see Graph 2], but even the worse-case 0.005% here is still ~300x lower than that from the average pick-up! The M8x Vinyl’s ultrasonic response is flatter than the Nu-Vista Vinyl 2’s (both are –0.05dB/20kHz before diverging to +0.09dB/100kHz vs. –1.4dB/100kHz, respectively) but the bass still rolls away gently to –3dB/4Hz. The ‘Mild’ subsonic filter [dotted trace, Graph 1] adopts the IEC profile, rolling off below 100Hz to –3dB/23Hz and –6dB/14Hz while the ‘Standard’ subsonic filter [dashed trace] has a +0.8dB lift at 25Hz with a ~3rd-order roll-off thereafter to –6dB/13Hz. The M8x Vinyl’s MM/MC input overload margins are sufficient, but lack the massive headroom enjoyed by the Nu-Vista Vinyl 2 [see boxout]. PM