Pre/Power Amplifiers

While there are no fewer than six alternate gain settings (57dB, 60dB, 63dB, 66dB, 69dB and 72dB) in practice the (balanced XLR) gain is far higher – amounting to 64.5dB, 67.5dB, 70.5dB, 73.5dB, 76.5dB and 79.5dB, respectively, with the volume control set at 0.0dB. You can add a further 11dB on top with the preamp volume at full! All this gain almost inevitably impacts on input overload margins so it's no surprise to discover darTZeel's phono stage clips (1% THD) with inputs beyond 5.85mV, 4.10mV, 2.93mV, 2.10mV, 1.45mV and 1.15mV, respectively. To ensure the highest groove modulations are faithfully reproduced, your MC's rated output should not exceed 0.7mV/5cm/sec (700µV) using the least sensitive ('57dB') gain setting.

On the other hand, darTZeel's phono stage is perfectly set up for the lowest output cartridges, not only because of the huge gain on offer but also its low noise and wide A-wtd S/N ratio – 80.5dB (re. 500µV in/1V out) across all six settings. Distortion is low too, from 0.0015% midband to ~0.01% at the bass/treble extremes [red infill, inset Graph]. The RIAA eq response [black trace] is flat to within –0.0dB/+0.5dB from 20Hz-20kHz, rolling off more steeply with the subsonic filter [dashed trace] from –0.5dB/35Hz to –6dB/10Hz. Finally, with the optional 'Neumann' pole, the ultrasonic response lifts from +0.75dB/20kHz to +7.1dB/100kHz [red trace]. This is a true 'artisan' phono stage. PM