Here is Jim Rush preparing to start a blind listening test at the Rocky Mountain Audio Fest 2012.
PTE was proud to display with some very fine analog and digital equipment. Our test signal was created by the excellent Soundsmith Hyperion cartidge mounted on a Graham 2.2 tone arm with the vinyl turned by the George Warren turn table. This signal was conditioned by the PTE MMMC-R phonograph preamplifier. Only pure analog recordings were played, primarily direct to disc recordings.
As you can see from the diagram, the signal was digitized and then returned to analog by the Antelope Eclipse mastering A/D and D/A converter. The signal was processed at 192 kilosamples / sec @ 24 bits /sample.
Volume was controlled by the T+A 2030 preamplifier and this signal was then sent to the PTE biamplified Phoenix powered monitors which are pure analog: Class AB amplifiers and active filters only.
After allowing each participant in the test to hear and know which signal he was listening to, we randomized the signal and asked the participants to tell us which signal they were hearing, the analog (point A) or the digital (point B).
Each listener was given five trials.
The Data are tabulated below.
Interestingly, there were a few listeners who got five right and we invited them to try again. When asked what they were listening to, one replied the cymbals, and another said the depth of the soundstage. Most listeners commented how hard it was to hear a difference. Steve Stanley got 8 out of 10 right.
PTE's Blind Testing of Analog versus Digital at RMAF 2012