HOLOAUDIO MAY (LEVEL 3) D/A PROCESSOR
The email from Herb Reichert was intriguing. “I am, with great difficulty writing about HoloAudio’s new two-chassis May DAC,” he wrote. “It is death quiet and very natural. It makes every recording sound non-digital.”
Once Herb had finished writing his review of the HoloAudio for the August issue’s Gramophone Dreams column, I sped to his Bed-Stuy bothy and grabbed the May DAC, both to get it on my test bench and to take a listen for myself.
The review sample was the top-of-the-line Level 3 version,1 with both the processor and power supply having the serial number 1911541872. Before doing any listening, I measured the May with my Audio Precision SYS2722 system (see the January 2008 “As We See It”2). Apple’s USB Prober utility identified the May as “Holo Audio UAC2.0 Gen2 Enhanced” from “Holo Audio.” The USB port operated in the optimal isochronous asynchronous mode, and Apple’s Audio-MIDI utility revealed that, via that input, the May accepted 24-bit integer data sampled at all rates from 44.1kHz to an extraordinary 1536kHz. The AES/EBU and S/PDIF inputs, including Toslink optical, accepted data sampled at rates up to 192kHz.
The May has four operating modes: NOS (for Non-OverSampling); OS (OverSampling PCM
