Pre/Power Amplifiers

With no phono stage or integrated DAC on board – EMM Labs offers the optical pick-up-compatible DS-EQ1, and DV2 and DA V2, respectively, to fulfil these roles – the PRE remains a fully analogue, balanced line preamplifier. And a remarkably transparent amplifier it is too... The volume control is precisely calibrated in both steps and absolute level, so +6.0dB on the display represents exactly +6.0dB input/output gain, 0dB is unity gain, and so on. Steps of ±0.5dB are offered down to –33.0dB, ±1.0dB from –33dB to –40dB and ±2.0dB thereafter down to the lower limit of –68.0dB. Accuracy is within ±0.0dB down to a volume/gain setting of –40dB, within ±0.05dB to –50dB and within –0.2dB at a setting of –60dB. The alternative ‘Units’ option offered by EMM Labs covers the same range in 0-100 steps up to a maximum balanced output of 20.1V. The maximum input level tolerated is 12.5V.

The frequency response is utterly unaffected by volume position – still not something that can be taken for granted these days – and is ruler-flat to within ±0.005dB from 1Hz to 100kHz [see Graph 1] just as the balanced output impedance remains a ‘flat’ 72.4ohm ±0.05ohm from 5Hz-100kHz. The PRE’s A-wtd S/N clocks-in at a respectable 94.3dB (re. 0dBV) while the residual noise is a very low –97.3dBV (14µV). Distortion, as anticipated with this exceptionally ‘transparent’ design, is very low at a barely perceptible 0.00004-0.0003% (20Hz-20kHz, re. 0dBV), rising fractionally to just 0.001%/40kHz [see Graph 2, below]. Channel balance is a super-tight 0.003dB and stereo separation better than 100dB from 100Hz-20kHz. The PRE is as close to the proverbial ‘straight wire with gain’ as we have seen, heard and measured in HFN for many years. PM