Hegel V10 Phono Preamplifier Lab Report

Lab Report

When Hegel's chief designer, Bent Holter, set about maximising the versatility of the V10 design there was an acceptance that this came at a cost: users would need to negotiate fiddly little DIP switches to select between the various options. The +20dB extra gain that separates MM and MC inputs, and their respective 0dB, +5dB, +10dB and +12dB 'fine gain' settings are all selected via DIP toggles, as are the subsonic filter and the various impedance (MC) and capacitance (MM) loads on offer. Hegel claims +40dB, +45dB, +50dB and +52dB gain for its MM input and +60dB, +65dB, +70dB and +72dB for MC, values that are closely matched on test at +40.3dB, +45.8dB, +50.8dB and +52.8dB for MM and +60.6dB, +66.1dB, +71.1dB and +73.0dB, respectively, for MC (all RCA single-ended in/XLR balanced out).

In practice, the lowest MM gain setting offers a 9.69mV sensitivity but the +5dB option with its 5.16mV sensitivity and very healthy 123mV input headroom will be the best 'default' for high output MMs. Similarly, the 'MC +5dB' setting – a sensitivity of 494µV with an input overload limit of 12.5mV – is ideal for the vast majority of 'coils. Moreover, this excellent range of sensitivities, coupled with at least 27dB of headroom at each step, is complemented by useful A-wtd S/N ratios of 79dB (all MM gain settings) and 78dB (all MC settings).

RIAA equalisation is also very flat and extended out to 100kHz within ±0.25dB, its steep subsonic filter amounting to –3.5dB/20Hz and –13dB/12Hz [see Graph 1]. If you have big, reflex-loaded speakers then this sub filter should be engaged. The RIAA-eq'd distortion [Graph 2] is slightly higher at bass frequencies, although 0.005% is still 100-1000x lower than any vinyl front-end! The minimum of 0.00028%/5kHz is spectacularly low. PM

421hegel.lab1

RIAA-corrected frequency response (subsonic filter, dashed) from 5Hz-100kHz at 0dBV via MM

421hegel.lab2

Distortion extended frequency via MM input re. 0dBV (5Hz-40kHz, black, left; red, right)

Input loading (MM/MC) 47kohm / 33-550ohm
Input sensitivity (re. 0dBV) 9.7/5.2/2.9/2.3/0.9/0.5/0.28/0.23mV
Input overload (re. 1% THD) 238/123/71/56/22/13/6.8/5.4mV
Max. output (re. 1% THD) / Imp. 23.9V / 96.5ohm (20Hz-20kHz)
A-wtd S/N ratio (re. 0dBV) 79.4dB / 76.9dB (MM/MC)
Freq. resp. (20Hz-20kHz/100kHz) –0.19dB to +0.05dB / +0.29dB
Distortion (20Hz-20kHz, re. 0dBV) 0.00024–0.0049% (MM)
Power consumption 5W (1W standby)
Dimensions (WHD) / Weight 210x60x280mm / 2.2kg
Price £1350

COMPANY INFO
Hegel Music Systems AS
Oslo, Norway
Supplied by: Hegel Music Systems AS
+47 22 605660
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