FOLLOW-UP
THIS ISSUE: Jim Austin measures and auditions the CH Precision D1.5 player/transport with the correct firmware; the measured performance of the EJ Jordan Marlow loudspeaker and the Paradox Phono 70 phono preamplifier.
CH PRECISION D1.5 SACD/MQA-CD/CD TRANSPORT/PLAYER
When I reviewed the CH Precision D1.5 player/transport in the March 2022 issue—I reviewed it mostly as a player—I was very much impressed by its performance.1 It was at its best as a SACD player. It also sounded very good playing MQA CDs. (It was my first experience hearing an MQA CD on a capable player, so I had little to compare it to except the other formats.)
The sound on CD was exemplary—probably the best CD sound I’d heard—but it was not as good as with the other formats. Which was expected.2
When JA measured as expected. In the time domain, he observed a conventionallooking minimum-phase filter, with no pre-ringing but 5–6 periods (about 550μs) of post-ringing. In the frequency domain, he found a very fast rolloff: With CD playback, the response “was flat to 12.5kHz but then was down by 1.1dB at 15kHz, by 3.9dB at 16kHz, and by almost 10dB at 17kHz.” At 20kHz (widely considered the top of the audioband, although at 58 years old I can’t hear that high), the response was down by a full 50dB. “With the ear’s reduced sensitivity in the top audio octave, the premature rolloff will be difficult to hear, but it does suggest an error in the programming of the digital reconstruction filter,” JA wrote.
