Ted Smith presents discrete DSD DAC to PNWAS

garylkoh

WBF Technical Expert (Speakers & Audio Equipment)
Sep 6, 2010
5,479
70
545
Seattle, WA
www.genesisloudspeakers.com
#1
Ted Smith is a longtime friend of PNWAS and was the lead designer of the new PS Audio DirectStream DAC.

Over three years ago, Ted presented an early prototype of this DAC. I remembered liking it a LOT, and members asked if it would ever get into production. It is a discrete DSD-based DAC. All of the input processing, upsampling, DSP and DSD conversion is done in field-programmable gate arrays (FPGA; a type of software configurable hardware). The analog output is a purely passive filter based on transformers. In the PS Audio unit, the digital and analog boards Ted designed are direct replacements for the boards in a current PS Audio Perfect Wave DAC or Perfect Wave DAC Mark II, enabling a field upgrade for owners of these units, to a DirectStream DAC.

One feature of the FPGA input processing is that there are no PLLs (phase loop locks): the bits are pattern matched to figure out what’s coming in and then they are placed into a buffer. In a sense, all inputs are locked at all times. You can go from input to input seamlessly and you can change sample rates of incoming material seamlessly. Most importantly, you can go from PCM to DSD seamlessly. This architecture also leads to a very low susceptibility to incoming jitter. I2S, AES/EBU, S/PDIF and TOSLink within their bandwidths all sound the same. For 96k and below, optical TOSLink can sound better since it can eliminate ground loops.

All digital inputs are upsampled to wide words at 28.224 MHz (10 x the DSD rate!). Then that signal is sigma delta modulated to double rate DSD and then lowpass filtered.

The upsampling filters are chosen to keep as much detail as possible not for computing convenience: they use a lot of CPU power, but the FPGA has the resources to do a great job. The result is that the FPGA digital processing looses less audio information than most other designs.

Ted will be present to talk and answer questions about the DAC.

A couple of Executive Committee members have already heard this DAC and they have reported that it sounds really great. Everything in the DAC was designed to get your toes tapping, to allow you to enjoy all the music you already have. The DirectStream DAC uncovers more music than we knew was present in any of our sources, from Redbook to hi-rez PCM, to DSD.

As usual - visitors and guests welcome.

Thursday, May 8th. 7:30pm
Mercer Island Congregational Church (basement)
4545 Island Crest Way
Mercer Island, WA 98040
 

Bruce B

WBF Founding Member, Pro Audio Production Member
Apr 26, 2010
6,813
216
560
Seattle, WA
www.pugetsoundstudios.com
#3
I have been waiting for this meeting for a while. While I'l heard the PS Audio DAC at AXPONA, I couldn't get a good handle on what it was doing with the music. I heard a prototype of Ted's DAC when he brought it over to my studio a couple years ago. I was really impressed with it then. Fast forward to last night and here are my thoughts.
I sat off to the side for the first part of the meeting so I really couldn't tell what it was doing. It sounded good and even off axis could hear a depth in the music that I'd never heard before from the club's Oppo. During the second part of the meeting, I sat dead center in the sweet spot. A couple of tracks were played that I was familiar with and I really liked the sound. Then the true test came. There were 2 discs played, first in the PS Audio transport going into the DAC and then played through the club's Oppo. Levels were set pretty close to even. The first thing I noticed was when played though the Oppo, it sounded like the singers (Rickie Lee Jones and Tierney Sutton) had stepped closer to me about 4'. Their voices had taken on a harsher tone with the leading edge of each note sounding like they had phlem in their throat. Playing the disc back through the PS Audio, the sound was more organic and natural. The vocals had appeared as they were more coherent with the back-up band. The stage sounded deeper and more natural. With the Oppo, the stage sounded pretty flat and not as wide as the PS Audio combo.

I wish to thank Ted and his wife for hosting the meeting. This DAC really impressed me and would love to hear it up against the Lampi.

Ted.JPG
 

edorr

WBF Founding Member
May 11, 2010
3,146
7
36
Smyrna, GA
#4
I have been waiting for this meeting for a while. While I'l heard the PS Audio DAC at AXPONA, I couldn't get a good handle on what it was doing with the music. I heard a prototype of Ted's DAC when he brought it over to my studio a couple years ago. I was really impressed with it then. Fast forward to last night and here are my thoughts.
I sat off to the side for the first part of the meeting so I really couldn't tell what it was doing. It sounded good and even off axis could hear a depth in the music that I'd never heard before from the club's Oppo. During the second part of the meeting, I sat dead center in the sweet spot. A couple of tracks were played that I was familiar with and I really liked the sound. Then the true test came. There were 2 discs played, first in the PS Audio transport going into the DAC and then played through the club's Oppo. Levels were set pretty close to even. The first thing I noticed was when played though the Oppo, it sounded like the singers (Rickie Lee Jones and Tierney Sutton) had stepped closer to me about 4'. Their voices had taken on a harsher tone with the leading edge of each note sounding like they had phlem in their throat. Playing the disc back through the PS Audio, the sound was more organic and natural. The vocals had appeared as they were more coherent with the back-up band. The stage sounded deeper and more natural. With the Oppo, the stage sounded pretty flat and not as wide as the PS Audio combo.

I wish to thank Ted and his wife for hosting the meeting. This DAC really impressed me and would love to hear it up against the Lampi.
Interesting. Hope to take possession of a unit myself shortly for in home audition. One interesting point is this though. Both Paul and Ted have been pretty adamant since its release (and to insiders even before its release) that this DAC is completely agnostic to quality of the input source (with the exception of USB), and all S/PDIF - AES/EBU should sound the same. Based on your observations this appears NOT to be the case.
 
May 30, 2010
16,887
1,689
720
Portugal
#5
I have been waiting for this meeting for a while. While I'l heard the PS Audio DAC at AXPONA, I couldn't get a good handle on what it was doing with the music. I heard a prototype of Ted's DAC when he brought it over to my studio a couple years ago. I was really impressed with it then. Fast forward to last night and here are my thoughts.
I sat off to the side for the first part of the meeting so I really couldn't tell what it was doing. It sounded good and even off axis could hear a depth in the music that I'd never heard before from the club's Oppo. During the second part of the meeting, I sat dead center in the sweet spot. A couple of tracks were played that I was familiar with and I really liked the sound. Then the true test came. There were 2 discs played, first in the PS Audio transport going into the DAC and then played through the club's Oppo. Levels were set pretty close to even. The first thing I noticed was when played though the Oppo, it sounded like the singers (Rickie Lee Jones and Tierney Sutton) had stepped closer to me about 4'. Their voices had taken on a harsher tone with the leading edge of each note sounding like they had phlem in their throat. Playing the disc back through the PS Audio, the sound was more organic and natural. The vocals had appeared as they were more coherent with the back-up band. The stage sounded deeper and more natural. With the Oppo, the stage sounded pretty flat and not as wide as the PS Audio combo.

I wish to thank Ted and his wife for hosting the meeting. This DAC really impressed me and would love to hear it up against the Lampi.
Thanks for reporting Bruce. Why not hearing it against the PB?
 

rbbert

Well-Known Member
Dec 12, 2010
3,502
71
485
Reno, NV
#7
Interesting. Hope to take possession of a unit myself shortly for in home audition. One interesting point is this though. Both Paul and Ted have been pretty adamant since its release (and to insiders even before its release) that this DAC is completely agnostic to quality of the input source (with the exception of USB), and all S/PDIF - AES/EBU should sound the same. Based on your observations this appears NOT to be the case.
it sounds to me that the Oppo was played separately, not as an input to the PS DAC? I too have been wondering how this unit compares to the Lampi (level 5?)
 

Bruce B

WBF Founding Member, Pro Audio Production Member
Apr 26, 2010
6,813
216
560
Seattle, WA
www.pugetsoundstudios.com
#8
it sounds to me that the Oppo was played separately, not as an input to the PS DAC? I too have been wondering how this unit compares to the Lampi (level 5?)
Correct... the Oppo was using its own DAC
 

Bruce B

WBF Founding Member, Pro Audio Production Member
Apr 26, 2010
6,813
216
560
Seattle, WA
www.pugetsoundstudios.com
#10
Thanks for clarifying. although the Oppo is not slouch, that should be "no contests". I thought it was used as a digital transport into the DS.
The PS Audio DAC was using 2 sources, a laptop using Foobar and the PS Audio transport. The transport was using multiple inputs to the DAC and Ted demonstrated by changing inputs to show it was the same.
 

edorr

WBF Founding Member
May 11, 2010
3,146
7
36
Smyrna, GA
#11
The PS Audio DAC was using 2 sources, a laptop using Foobar and the PS Audio transport. The transport was using multiple inputs to the DAC and Ted demonstrated by changing inputs to show it was the same.
Different inputs from the same source though (the transport). The initial contention from PS Audio was that a piece of junk $300 PC would sound as good as the transport (or any other source). They have since backtracked from that contention, confirming difference in various USB configurations and source quality. I'll listen for myself comparing USB and my Lynx AES/EBU source.
 

Alrainbow

Well-Known Member
Dec 12, 2013
1,850
508
345
NYC , USA
#13
Edorr I have it playing now. It is really good. As my msb is at my office rig now and I cannot compare . But I can say it is very good . It is something that I could listen too all day . It plays dsd and PCM very well. It has the magic sound both ways. You will not need a blindfold to tell . You will be smiling with both of them. As a A/B test may show a preference it's not like most other dacs I have ever heard. I cannot wait for your mini review , for the price it's amazing . Now I have my level 7 coming next week and I can do a three way shoutout. But I am thinking as there will be a difference it's not going to be important. It's has details and a relaxed sound that is really good. I am using a bull shiit USB cable nothing special . In fact it's the cAble that came with my offramp from Steve n. And a win 7 USB from mother board with a I7 intel chip.
Not even with my win server 2012 . It has a rally real sound to it. I have plYed opus 3 no 3 , Elvis 57 and flacks from several flac hd tracks downloads and even hd tracks buena vista social club is very good .
Al
 

About us

  • What’s Best Forum is THE forum for high-end audio, product reviews, advice and sharing experiences on the best of everything else. A place where audiophiles and audio companies discuss existing and new audio products, music servers, music streamers and computer audio, digital to audio converters, turntables, phono stages, cartridges, reel to reel, speakers, headphones, tube amplifiers and solid state amplification. Founded in 2010 What's Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals we enjoy learning about new things and meeting new people and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing