Phono Preamplifiers

Tested via the E-Glo Petit B’s RCA in/XLR out, the gain achieved is typically +5dB higher than indicated, specifically +45dB, +50dB, +55dB, +61dB, +71dB and +76dB for the 40, 45, 50, 55, 65 and 70dB settings, respectively. For a 0dBV (1V) output this equates to MM/MC sensitivities of 5.69mV for the 40dB setting, ideal for MMs with a healthy output like Ortofon’s M series [HFN Mar ’11], down to 158μV for the 70dB setting, suited to very low output MCs like the Kensington Audio C-600 [HFN Dec ’25]. Allied to this impressive gain range are comprehensive input loading options ranging from 10ohm to 1.2kohm suited to most MCs, and 30-70kohm (with 50-620pF) if you fancy fine-tuning the load ‘seen’ by an MM pick-up. However, because the E-Glo Petit B has no formal MM/MC inputs – the user selects the gain and input loading required, regardless of cartridge type – the A-wtd S/N ratio jumps between 81.1-84.4dB for a 5mV input (MM) and a lower 64.2-66.1dB for a 500μV input (MC).

Input overload margins are very generous provided the first three gain settings (40-50dB) are treated as MM and the higher three (55-70dB) are used with MCs. In this case all settings offer in excess of 20dB input headroom – sufficient to accommodate the wildest of grooves. Distortion is very low and tolerant of a wide output range – figures of 0.0005-0.0055% (re. 0dBV, 20Hz-20kHz) being illustrative [see Graph 2]. The Petit B has a gentle +0.5dB bass boost between 10-100Hz [see Graph 1] but this is rolled away below 20Hz (–3dB) to 10Hz/–17dB with the subsonic filter engaged (toggle pushed back). The latter will be the ‘safe’ option if you have large, reflex-loaded loudspeakers placed anywhere near your turntable! PM