When a new or existing file is MQA encoded, the additional compressed, or ‘folded’ data points are included, out of bandwidth. These reintroduce lost information, but also lost timing cues, once the file is replayed and MQA decoded/up-sampled. Technically of course, this means that MQA is NOT a lossless system by definition, as it actually adds and in some cases effectively ‘overwrites’ information! This essentially semantic point is the focus of much of the pro/anti MQA debate. Personally, I’m entirely agnostic: I don’t care how it works, beyond the academic level. I do care about how it sounds – and that’s the point of this piece. More specifically, I care about its impact on the sound of CD replay, as this represents an opportunity to gauge its benefits using reference material that is more reliable and stable than files, streamed or locally stored.
The arrival of CH Precision’s D1.5, along with my own burgeoning collection of discs that include MQA encoding, was the first opportunity to compare MQA CD to the other, popular disc formats (based around CD and SACD). But the first point to make is that, as far as most current recordings are concerned, the benefits or otherwise of including MQA encoding are somewhat moot. The disc either is or isn’t MQA encoded and (far from surprisingly) I’ve yet to discover a current release that is available in both forms. That means that for comparative material we need to look at earlier recordings, often highly regarded albums worthy of updated or re-release.
However, even if you assemble titles that are available across the different formats, it’s a comparison that is far from straightforward, as often, the inclusion of MQA encoding is not the only differentiating factor. If we look at discs in my collection that cover all three formats (CD, MQA CD and SACD) then the list includes:
Du Pré/Barbirolli/LSO, Elgar, Cello Concerto
Kleiber/Wiener PO, Beethoven, Symphonies Nos 5 & 7
Kubelik/Boston SO, Smetana, Má Vlast
Rostropovitsch/Karajan/Berliner PO, Dvorak, Cello Concerto
John Coltrane, Giant Steps
John Coltrane, Ballads
Factor in standard and MQA encoded CDs only, foregoing SACD, and that list grows considerably, including, amongst others:
John Coltrane, My Favorite Things
Rickie Lee Jones, Self Titled First Album
Lisa Batiashvili, Tchaikovsky, Sibelius and Shostakovich Violin Concertos
Martha Argerich, Prokofieff, Ravel, Chopin and Liszt Piano Concertos
Mixing up the differences and distinctions were Super Hard Material (SHM) and UHQCD discs, the latter combining the harder plastic envelope with a photo-polymer interface for the silver (as opposed to aluminium alloy) pit layer. The range of samples spread from straight CD to straight SACD, but with every other combination in between. Most of these discs have been in my collection for a while, but the D1.5 offered their first MQA-certified replay (the Wadax Atlantis Transport will decode MQA encoded CDs, although the process – unlike MQA encoded file replay via the Reference DAC – is not certified and therefore offers no basis for comparison). Keeping things simple, I hooked up the CH Precision D1.5/X1 to the Neodio A2 amplifier, driving the Wilson DAWs. All discs were treated to the Furutech DeStat III each time they were played, all transport operations were input manually and the operational sequence was strictly maintained – so no lazy skipping between tracks!
