PS Audio's Paul McGowan Weighs In On MQA

Here's Paul McGowan from the PS Audio Forum:
"So far MQA decoding has only been worse and that has not changed. We suspect (as do they) that it’s because the tricks they’re using with filters to try and make the sound better (closer to the original source material in their parlance) screws with our own in the DAC. They then suggest they need to tune their decoder to our filters for best results.

"If that’s all true then we’re out. As you’ve seen with Torreys, Ted and the engineers continue to improve the state of the art with digital filters on a regular basis – and one of the whole reasons we went to an FPGA based DAC in the first place was the freedom to improve the product’s performance over time. If we were restricted in what we could to future developments, held back because everything in the USB chain had to be 'fixed' by the MQA engineers first… that would be nuts.

"They’ve never said that has to be so and I am merely speculating as we wait for an answer.

"I too wish they’d just release this as software so the compressed file could be decoded and leave the DAC design to us."

This raises an interesting point, which Paul states very clearly, " of the whole reasons we went to an FPGA based DAC in the first place was the freedom to improve the product’s performance over time." For those DAC designers who stick to off-the-shelf chip-based digital filters and D/A conversion, MQA may very well be an easy add-on and improvement. But for those companies who choose to roll their own digital processing like PS Audio, Schiit, Ayre Acoustics, Playback Designs, Chord, etc, MQA may introduce restrictions and dependencies on MQA into their design process that some may not be willing to take on.

Time will tell.

MQA Controversy | DirectStream DAC | Forums.

Bob Stuart Responds

The MQA decoder uses signal processing (including filters) that match the hardware to the encoder's target, completing an end-to-end chain. This makes it technically possible to provide the very fine temporal resolution necessary for the analogue input and output to match closely across a wide variety of recordings.

We work with partners to ensure that when MQA is being decoded the result is as close as possible to that heard in the studio.

However, we also encourage diversity and don't intrude at all on the craft or operation of products when they are not playing back MQA files.

We support many different DACs and platforms ranging from simple to complex. If a DAC uses custom DSP (maybe in an FPGA) then for non-MQA playback we encourage manufacturers to do their own thing and this is readily accepted by several already implementing MQA in their designs.

Examples already in the market where custom filters can be selected for non-MQA playback include the Onkyo/Pioneer DAPs, Mytek's Brooklyn and the Meridian UltraDAC.

Bob Stuart, MQA

miguelito's picture

I understand the "tuning to a DAC" argument MQA is making - it is not an unreasonable argument for lower end chips. But PSAudio's argument about having the ability to fine tune filters is also quite reasonable.

Clearly MQA could work by outputting a "standard" PCM stream after decoding - as it did on the Auralic Aries. The reason they changed course is simply they do not want to give up the ability to charge a royalty on the decoding end.

Bromo33333's picture

PS Audio did stop short of condemning MQA as being inferior, and previous blog posts never quite praised it, other than it was pretty close to 24/192 which they found remarkable. And this, the main objection was them not wanting to give up the investment they had made in FPGA chipsets (and having to use off the shelf DAC's) which I am sure they view as one of their main differentiators. The royalty payments probably rankle as well.

The weather seems to see some clouds in the audiophile world, I sense a marketing cold war beginning with the people who invested heavily in ladder DAC's, and custom DSP on one side, and the ones that use off the shelf DACs on the other.

My prediction? MQA won't be considered an audiophile format to the elite as a result. But it's home will be in streaming services where the bandwidth in most homes can barely support a FLAC stream of 16/44.1 let along 24/96.

Of course, if Apple Music starts selling 24/96 it could be "game over" for MQA even if MQA proves better. Best tech doesn't always win.

Evgenyevich75's picture

Music playback does not need to be complicated. If a revolutionary new technique is genuinely good, very little explanation will be needed. However, despite being years in the making, answers (or lack of it) from MQA to simple questions raise more questions. They have not gained sufficient momentum in the industry. Why? My view is that it is a trick. Trickery to achieve monopoly perhaps? Paul is right, but I suspect he is being too polite.

EternalSounds's picture

I can understand Paul McGowan's apprehensions with regard to the the FPGA DirectStream models. These are PS Audio's 'flagship' technology and the company's 'bread & butter'. But what about adding MQA to the NuWave model? It would seem a reasonable move, unless...

Does the possibility exists that MQA might be TOO good, and ultimate undermine future DirectStream sales? Maybe.

I've owned the low-end PS Audio Digital Link III DAC for several years and it has performed beautifully with my simple and modest setup. I exclusively stream TIDAL and Pandora via three Logitech Squeezebox Touch, Direct Link III, then three pairs of various Martin Logan speakers. As they say, if it's not broke, don't fix it. ;)