Dr. AIX's POSTS — 03 April 2015


Thanks to my very gracious host Paul McGowan carving out a couple of hours from his very busy day, I was treated to a tour of the PS Audio facilities in Boulder, Colorado on Wednesday of this week. I wrote part I about my experience yesterday. You can read it by clicking here. Today’s post focuses on the time that Paul and I sat in his very high-end demo room playing a variety of my tracks and some of the tracks from the PS Audio collaborative record project.

After I finished burning a DVD-R of about a dozen real HD-Audio stereo WAV files in Paul’s office, we returned to the PS Audio demo room to do some careful listening. The room is about 20 feet long by 18 wide and maybe 10 feet high…the size of a reasonable home theater, except this room doesn’t cater to video or surround sound. It’s strictly an ultra high-end 2-channel playback environment. The first things you notice are the two gigantic Infinity IRS V speakers. As you can see in the picture below, they are very large. The towers include 76 EMIT tweeters, 24 EMIM midrange drivers, and twelve 12-inch polypropylene woofers in four towers. Originally selling for $65,000, according to Paul there were only 56 pairs ever made. He snagged a pair for considerably less the original price and squeezed them through the door of his demo space. They are huge.


I wrote to Paul and asked about the rest of the signal path. Here’s what he told me about the system:

“The transport is our Memory Player, the PerfectWave Transport (everything is read from a DVD ROM drive, stripped of its timing info and placed into a 64mB RAM buffer, then output with a fixed low jitter clock). Then into DirectStream, up samples 10X and converted to 2X DSD. The output of DirectStream is right off the FPGA DSD output into a simple analog filter and into the preamplifier. The preamp is a Aesthetix Calypso tube and that into the new BHK Signature Power Amplifier with its own vacuum tube input, MOSFET outputs.”

There are shelves full of demo CDs and DVDs on one wall of the room and I noticed a copy of my High-Resolution Experience Sampler among the collection. Having learned that the PerfectWave Memory player was limited to CD/DVDs and couldn’t handle my Blu-ray sampler, I thought that perhaps the Hi-Res Experience DVD could be the source for our listening session. Paul inserted the disc into the disc drive of the unit and nothing happened. The AIX sampler has two sides…one side is formatted as a DVD-Video disc and the other is a DVD-Audio disc. Unfortunately, the PerfectWave Memory Player isn’t compatible with those formats. It can read and play CD-Audio, CD-ROM, and DVD-ROM discs. But if you have any Pure Audio Blu-ray discs or DVD-Audio/Video discs, it rejects them. We were back to the DVD-R that I burned in Paul’s office.

If you’ve been a reader of this blog for a while, you’ll know that I’ve written critically about Paul’s fixation on DSD and what I perceive as illogical design decisions in some of their recent products. Paul is well aware that I sit on the other side of the 1-bit DSD divide. For all of the reasons that I’ve discussed over two years of posts AND because I’m a recording engineer/studio owner, I’m one of those that categorically dismisses the whole 1-bit nonsense. My comments about PS Audio products and Paul’s endorsement of DSD have nothing to do with him personally. I have tremendous respect for Paul as an advocate for better sound. He runs a very successful business, employs a bunch of people, and advocates for his position and products, as you would expect. It was very encouraging that he and I had a very positive experience on Wednesday. It is possible for two people with different opinions on high-end audio to find common ground and I look forward to the beginning of a real friendship. I felt his commitment to better sound and look forward to exploring mutual opportunities.

But the first component in his playback system comes up short when it comes to the popular formats for delivering high-resolution audio. I couldn’t use a USB stick to pass HD-Audio to his system and the PerfectWave MEMORY player isn’t compatible with DVD-Audio/Video or Blu-ray discs. The design decisions made by PS Audio seem unnecessarily limited. I can certainly agree with the offloading of the digital stream into a large data buffer and clocking the output with a very low jitter clock but to restrict the inputs to DVD-ROM and CDs is far too limiting in this file based world.

Here’s the sales promo from the PS Audio website:

“The Memory Player plays both standard and high resolution audio on CDs and DVDs sending perfect digital audio data from its solid state memory directly to your DAC and then onto your loudspeakers, eliminating jitter. All music extracted from your CD or DVD disc plays from the PWT’s internal solid state memory, not the disc itself. The performance is remarkable.”

OK, I like the concept except that it presents a real challenge compared to other players. From the FEATURES page describing the PWT:

“High resolution downloads from sites like HD Tracks can easily be converted from FLAC or ALAC to WAV files on your computer, transferred to a DVD and played in all their high resolution glory on the PWD.”

What the above statement says is that you have go through a series of not-so-trivial steps before you can hear a high-resolution downloaded file. First, you download a FLAC file from HDtracks. Then you have to convert it using a piece of audio software to a WAV file (which strips off all of the metadata) and burn a DVD-R disc to insert into the PWT. This strikes me as a couple of too many hoops to jump through to hear a downloaded HD track. Shouldn’t a high-end player handle audio files directly?

I don’t follow the sales trends for front-end media players, but I think the Oppo line of players offer more flexibility and value than the PerfectWave Memory player…and they sound pretty amazing. I’m planning on using on as the front end in my AXPONA high-end demo room.

To be continued…

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About Author


Mark Waldrep, aka Dr. AIX, has been producing and engineering music for over 40 years. He learned electronics as a teenager from his HAM radio father while learning to play the guitar. Mark received the first doctorate in music composition from UCLA in 1986 for a "binaural" electronic music composition. Other advanced degrees include an MS in computer science, an MFA/MA in music, BM in music and a BA in art. As an engineer and producer, Mark has worked on projects for the Rolling Stones, 311, Tool, KISS, Blink 182, Blues Traveler, Britney Spears, the San Francisco Symphony, The Dover Quartet, Willie Nelson, Paul Williams, The Allman Brothers, Bad Company and many more. Dr. Waldrep has been an innovator when it comes to multimedia and music. He created the first enhanced CDs in the 90s, the first DVD-Videos released in the U.S., the first web-connected DVD, the first DVD-Audio title, the first music Blu-ray disc and the first 3D Music Album. Additionally, he launched the first High Definition Music Download site in 2007 called iTrax.com. A frequency speaker at audio events, author of numerous articles, Dr. Waldrep is currently writing a book on the production and reproduction of high-end music called, "High-End Audio: A Practical Guide to Production and Playback". The book should be completed in the fall of 2013.

(17) Readers Comments

  1. Paul and his son Scott are great guys, met Paul in my shop just after AC regenerators hit, and have talked w/ Scott enjoyably.Your comments point to what is both the best and simultaneously insidious aspects of the high-end audio business, to which your business is attached symbiotically.

    I know many celebrated principals of esteemed brands. To a man, they each are driven by a unique vision, and the brands and products on the market make this clear.One company decides something is important, another completely discounts the same value. It is basically impossible to unify the audio specialty industry. I put it this way: If significant loudspeakers stop selling, then the amplifiers and cables stop selling too. I also strongly feel that this activity which was once mainstream, now ivory tower/death row, should be collectively re-positioned as simply a logical constituent element of a high-quality lifestyle along w/ organic food, filtered water, non-synthetic fiber clothes, fresh flowers on the table, etc. I have spoken w/Paul about this.Like many’founding fathers’, he will ride the existing, out-moded business model ’til he retires; very little shift is possible if any. Most are a bit older than my 63 years. I have no answers, but here’s my bit:www.path-pureaudiotohealth.org, very crude but expressive of my belief system. Love to know what you think.Best, Craig

  2. Found a real interesting series of videos on youtube on the building of the PS Audio listening room you were in along with the setup of the Infinity IRS Vs. I’d love to get a listen to those speakers along with your room and the JBL horns.

  3. Hi! If I read you right, there was a PWT and a Direct Stream DAC (“DSD”). The DSD will accept digital source material via balanced, coax, Toslink, USB and I2S (HDMI) inputs. Why wasn’t the USB stick inserted into the USB input of the DSD?

    • I’m not sure. I’ll ask Paul.

    • The USB at the back does not work with mass storage devices. It expects a USB DAC.

      • Since the DirectStream is a DAC, I think you’re mistaken. The USB on the DirectStream is for connecting a computer to it.

        Mark, does your laptop have a USB port on it? If it does, then you could have used it instead of burning a disc.

        But this does point out one of the short-comings of the PWT – the fact that it wasn’t designed as a universal player, especially since it is touted as a high end audiophile disc player, is kind of mind boggling.

        What’s also kind of mind boggling is if Paul didn’t ask if you (Mark) if you had USB on your laptop so you could connect it to his DAC.

        • I did question the connection options offered. The route to the system seemed to be a DVD-R with ROM WAV files on it. That’s what we did.

  4. I can understand DSD not fitting into your recording/mixing/mastering workflow, and the rise in ultrasonic noise at the 2.8 MHz clock frequency used on SACDs starts low enough to obscure the upper harmonics of instruments that can be captured by modern microphones, but I’m not sure why you would object to a 1-bit system, at a high enough sampling frequency, being used for the A/D or D/A conversions. With a 5.6 MHz sampling frequency, the rise in the ultrasonic noise doesn’t start until nearly 50 kHz. with virtually all hardware on the market, 24/96 PCM is something that only exists in software – the A/D and D/A steps use fewer bits at higher sampling frequencies.

    • Because there is no way to produce commercial recordings natively in the format. You must convert. There are no sonic or production benefits from 1-bit system…why bother with new equipment etc when PCM is already better?

      • Perhaps I didn’t phrase my comment/question clearly.

        With the vast majority of DACs on the market – including those from Benchmark –, your 24/96 recording is being turned into something else in the D/A process. Why does it matter to you whether the conversion is done with 1, 5, or 6 bits? All of these have ultrasonic noise that needs to be filtered.

        At the other end of the process, I don’t know what ADC you use for your recordings, but, again, the conversion process usually involves relatively few bits at a high sample rate that is then converted to the 24/96 PCM format you manipulate in your DAW. If you were to look at the spectrogram of a 24/96 recording, it’s unlikely you would be able to tell whether the analog-to-digital conversion was done using a 1-bit or multibit architecture.

        • Andrea, I know that current ADCs and DACs are internally using very high sample rates and shorter words…even as short as 1-bit. And there is high frequency noise that is present until filtered. However, the processes for PCM based recordings and 1-bit are fundamentally different. This is readily apparent if you examine the spectra of a DSD 64 file and a PCM version of the same recording…I’ve done it. I have no interest in using DSD as a production format or as a delivery format. There is simply improvement in fidelity, it requires multiple conversions to accomplish anything, the files are larger, and the hoops you have to jump through to transmit files and make them play are too difficult.

          State-of-the-art PCM recording, post production, and delivery is just fundamentally easier, better sounding, and more convenient. Why anyone would choose to use DSD is beyond me…with the except that consumers have be mislead into believing that DSD recordings are “new and improved”. And because of misinformation they’ve been spending more money than necessary to get them.

          • I’m not disagreeing with anything you’ve written about the reasons why a 1-bit system is not appropriate for most music production workflows. My point is only that the hardware being 1-bit is a totally separate issue. As stated in my first comment, with a 5.6 MHz sampling rate, the ultrasonic noise doesn’t start rising until close to 50 kHz, so you won’t see it when decimating to 96 kHz. Since that decimation step usually happens in the hardware, you wouldn’t even know it’s a 1-bit system.

            The term Direct Stream Digital makes sense when applied to capturing the raw output of an analog-to-digital converter, and playing it back through a digital to analog converter that uses the same architecture. Here, Direct Stream is just a name. Maybe I’m misinterpreting your many references to this DAC, but it seems like you’ve been objecting to the way the conversion is done. The DAC may or may not sound good and/or measure well, but it’s not fundamentally changing the PCM data any more than is the Benchmark, or most other DACs.

          • It seems you want very much to draw the 1-bit high sample rate technique called DSD with PCM. I’m not sure why. If the inner workings of Delta Sigma is part of each method makes them the same for you, OK. The realities of working in DSD and the results of the conversion as well as the other flaws I mentioned makes it unusable for me and virtually all other studios and engineers. The audiophile community can rave about this new technology…I do not. And many other do not, including some of the format’s former supporters. It’s a diversion and should be forgotten in my opinion.

  5. OMG, yet another example of a high end manufacturer trying to cram a large speaker system into a too small room. They should know better.

    The example set here is just plain wrong and never mind all the tube traps behind the listener and ‘designed’ helmholtz resonators. Three chairs at the back of the room, give me a break. I am so disappointed that they did not see fit to build a room at least twice the size to ‘demonstrate their wares’ with the chosen speaker system and then to go on about the rooms tuning and features! It fails to underpin the manufactures honest intentions IMV. Sorry but there we are.

  6. Mark ,

    Still waiting for the conclusion on the soundroom visit. …

    • Oh man, I completely forgot about this. Let me see if I can dial it back up. Sorry.

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