This review page is supported in part by the sponsors whose ad banners are displayed below

Once we determined correct power polarity* with the help of a voltmeter and ground-lift cheater plug—check for lowest voltage reading between amplifier and wall-outlet grounds while the former is switched on without any other cable connections—the Reference One could be wired up.
__________________________________________

* Unlike 'one-way' 3-prong US plugs, European 2-prong Schuko plugs can be inserted into the wall either way. - Ed



We used the Reference One preamplifier in various settings. The first saw a sibling combo of Reference Phono One and Kaivalya monos with our Dr. Feickert Blackbird turntable or a PTP Audio Solid12 in for review. The preamp formed the stable back bone when alternating between Trafomatic phono amp and our resident Tri TRV EQ3SE equivalent on the source side; and the Kaivalya or Hypex NCore 1200 monos on the power amp side of the signal path. Where each of these components brought to the party its own distinctive character, the Reference One just did as told and directed traffic without complaints or personal opinion. The Tri showed off its usual lighter touch, the Kaivalya monos their EL84 perkiness and the Dutch NCore their limitless power and transparency.


As alternative to the Pnoe horns and thanks to a 10-meter run of new Nanotec MS #207 twin-shielded interconnect, we could easily activate our Avantgarde Duo Omega horns on the side wall by simply relocating the power amps. Driving these very long interconnects was no problem for the Serbian valve preamp and the very efficient 107dB horns did reveal no noise other than the expected vinyl crackles even at very close range. Respect!
Italian Trafomatic importer Salvo Giardina's system of Bel Canto Design source, Trafomatic Reference Pre, Trafomatic Reference 300B monos in custom real-wood chassis and Zu Audio Druid V

Going digital offered further possibilities. In combination with a PS Audio PerfectWave transport and matching DAC, the Reference One was a welcome alternative to the PWD's progressive nibbling of bit resolution when attenuation was invoked. Even modest 16wpc tube power running full throttle into 100dB+ speakers is not recommended when ear drums and window panes remain valued assets. Fully lossless attenuation as provided by XXHighEnd‘s streaming software running on a dedicated PC in combination with their Phasure NOS1 DAC needs no separate preamplifier and its designer actively dissuades their use. However a very good means to assess the impact on sound quality of a (good) preamp is to run a comparison between software attenuation and its hardware-based alternative. Setting XXHighEnd to 0dB attenuation (full speed ahead in other words) with the Phasure NOS1 DAC attached to the Reference One driving the high-power NCore monos into the Pnoe horns, we took notes on speed, transparency and life with an ‘f’ and not 'v'. We then took the same type of notes whilst attenuating the signal to -45dB and driving the NCores straight from the DAC.

Within the limitations of our means this test was merely indicative. The Hypex class D monos only accept balanced inputs, the Reference One only single-ended whilst providing for a balanced output through a discrete set of secondaries in the output transformer. We tried to smooth out this differences by using 10 meters of Nanotec MS #307 interconnect in XLR as well as RCA flavors thanks to the support of Hayashi-San of Nanotec Japan. Not completely to our surprise, the straight DAC/power-amp connection scored highest. The combination’s extreme S/N ratio—in excess of 130dB—prevents any detail from falling through noise floor cracks. Transparency though scored equally in both setups. Admittedly speed and life are matters of taste. We like the in-your-face experience of horns and for concerts sit as close to stage as possible. Introducing the preamp moved us further back into the venue. The seats were still very good but without the ‘touch and smell’ of front-row seating with its explosive life charge.