New Directions in Audiophile Computers

Transcription

1 β New Directions in Audiophile Computers John Mingo Managing Director Baetis Audio California Audio Show August, 2014

2 Why move from an SACD/CD player to a media server or computer? 1. The convenience of saving your discs for posterity. 2. Ease of use (no handling of the discs; immediate start-up). Oh yes, sexy GUI that impresses your friends; Especially if you use an Android or ipad to control the computer. 3. BETTER AUDIO than any disc player: a. No spinning turntable means no anomalies due to mechanical issues. b. Playing the audio file from RAM is the ONLY way to achieve perfect bit-streaming to the DAC. 8/16/2014 2

3 Why move from an SACD/CD player to a media server or computer? 4. The most important thing is that the disc player can be separated from the DAC-ing function a separate DAC almost always sounds better than the DAC circuitry within a disc player even the very most expensive disc players. And this applies to multi-channel sound as well as 2-channel audio. If you are moving from a player to a server (computer), you must budget for the DAC or pre-pro (MCh DAC). 8/16/2014 3

4 What s the difference between a music server and a media server (computer): 1. The term music server is generally applied to a computer that does not play all types of music 2. A real computer, running complex software that is updated often, can rip and/or play the following audio types: a. PCM ripped from CDs b. PCM in hi-definition downloaded from websites c. DSD ripped from SACDs d. DSD in hi-definition downloaded from websites e. Specially encoded PCM ripped from Blu-ray discs (e.g., DTS-HD Master; Dolby Digital TrueHD ) 8/16/2014 4

5 What s the difference between a music server and a media server (computer): 4. Most importantly, the media server (computer) can do things to the audio file (the computer file) that music servers can only dream of (yes, electronic circuits can dream; we re sure of it): a. Rip and play multi-channel music b. Rip and play any format of PCM WAV, FLAC, AIFF, ALAC, and hundreds more c. Rip and play the audio and video associated with a Blu-ray concert (in 2D or 3D and up to 4K, not just 1080p). d. Play professionally ripped SACDs in each of 5 ways (two of which are not even widely known). 8/16/2014 5

6 What s the difference between a music server and a media server (computer): 5. We re not done yet the truly remarkable thing about the modern powerful, multi-core computer is that it can do some things BETTER than are commonly done within even the very best DACs and multi-channel processors: a. Decode DTS-HD Master and TrueHD way better than a $10k pre-pro. b. Convert DSD to WAV in order to play via SPDIF or AES, not just USB. c. Allows the user to employ Digital Room Correction software that beats the firmware used in the very best pre-pros or separate Room Correction boxes. We are talking about time domain correction as well as simple equalization. 8/16/2014 6

7 What s are the downsides to the computer? 1. It can get complicated if someone does not provide the necessary education and customer support. Hint: If I can learn it, you can. 2. The computer can only do the Important things file management, decoding, transcoding, bit-streaming or Digital Signal Processing ( DSP ), but not the NECESSARY thing converting the digital signal into analog for the amps and the speakers. So, we can t discuss the computer without discussing the DAC or Pre-Pro (multichannel digital-to-analog converter). And the DAC is where a lot of the confusion exists. 8/16/2014 7

8 What s are the downsides to the computer? 3. Yes, each modern computer does have its own 2-channel and multi-channel DAC circuitry but the necessary Word Clocking is quite poor, and the inside of a computer is no place to put a quality Clock! Never use the computer s built in DAC process. You MUST have an external DAC. Moreover, we disagree with the notion that, somehow, placing a quality word clock inside the computer will improve the Computer s sound. We came to this conclusion solely via our empirical methodology a PCI card with a word clock did NOT make the DAC sound better, and, indeed, it did NOT sound as good as the same DAC using the SPDIF output from the computer (as long as the SPDIF is straight from the MB). 8/16/2014 8

9 How can you tell which audio output to use from the computer? Today, the makers of the world s DACs believe that the best audio output from a computer is its USB port. This HAD been true, but no longer, with the advent of DIY computer building, along with the rise of several professional audiophile computer manufacturers. The keys to the renaissance in SPDIF and AES are the new generations of CPUs with integrated high-def audio output no need for an additional sound card (and sound cards typically are not optimal now that the CPUs are so advanced). Still, most people believe that all computers are the same You use the USB output for your audio, and all that matters is how well the DAC plays the digital file coming to it from the USB port of the computer. 8/16/2014 9

10 How can you tell which audio output to use from the computer? Moreover, DAC makers that don t have USB inputs are considered to be out-of-date. Does this common wisdom seem familiar to you? Sounds a lot like the rise of CDs, where it took another 20 years before the common wisdom became instead how can we make digital sound more like vinyl? Still, it is the case that the best way to play hi-def music out of MOST computers is via USB i.e., all the Mac-minis and MacBook Pro computers in use. But just because USB is the ONLY way to play audio out of most computers does not mean it is the BEST way. To fully understand how the modern DAC industry is swayed by the use of USB ports from computers, let s discuss just one type of hi-def audio - DSD music in 2-channels or multi-channels. 8/16/

11 How good is DSD music and what is the best way to play it? First, we are true supporters of both major types of music file PCM and DSD. Both can be truly wonderful or quite lacking, depending on the engineering that went into the recording process. Similarly, hi-def PCM (e.g., a 192khz/24-bit downloaded file) can sound truly great or NOT as good as the original CD, depending on the engineering and then the playback process. Second, do NOT be taken in by claims that the DAC does native DSD. In truth, the vast majority of DSD-capable DACs play DSD only via one method DSD over PCM ( DoP ) via USB. But there are other methods. 8/16/

12 Ways of playing a DSD computer file: 1. DoP via USB 2. DoP via another output from the computer (SPDIF, AES, HDMI) 3. By transcoding, on the fly, the DSD file to PCM and playing it over any of the outputs from the computer (no, USB is NOT the best, not even the second best.) 4. By transcoding the DSD file to PCM (WAV) prior to playing, Then playing the WAV file via SPDIF or AES or HDMI (Our tests suggest that the USB port ranks fourth, not first). 5. By playing the native DSD file neither via DoP nor by transcoding to PCM, but by having the DAC itself receive the native DSD file. 8/16/

13 Ways of playing a DSD computer file: We know what you are thinking shouldn t the best way be #5 playing the native DSD file straight to the DAC? The answer is not at all clear. a. The vast majority of DSD capable DACs simply don t do #5. JRiver Media Center, the industry-leading computer audio software, is capable of playing DSD by bit-streaming the DSD file straight to the DAC over any type of output. We haven t yet compared one of these true native DSD DACs to the method of transcoding DSD into WAV then playing over one of the better traditional DACs. But we think we know which will win keep reading. 8/16/

14 Ways of playing a DSD computer file: b. Meanwhile, we have compared DoP via USB to ways #3 and #4 playing the DSD file via transcoding DSD to PCM, either on the fly or by first doing the transcoding to WAV, then playing the WAV via SPDIF or AES. Our listening team, plus several of our customers with DoP capable DACS, have done these comparisons at great length. The uniform conclusion? The DSF/DFF file sounds significantly better by transcoding to PCM (WAV) and playing via SPDIF or AES rather than DoP via USB. And there is a slight improvement by first transcoding the DSF/DFF file to WAV, then playing the file AFTER the transcoding has taken place (rather than the transcoding taking place on the fly). 8/16/

15 Ways of playing a DSD computer file: We don t know the technical reasons why our listening results favor transcoding to WAV and playing via SPDIF or AES. Nor have we yet auditioned a DAC that will accept true native DSD over SPDIF or AES. But we think we know part of the answer: a. When you instruct the computer, using JRiver, to transcode the DSF file into WAV, the resulting WAV file is approximately three (3) times the size of the DSF file!! b. When the WAV file is then played, JRiver says the resulting Bit-Rate is approximately three times the native Bit-Rate of the DSF file played as DSF. 8/16/

16 Here is the screen shot of the original DSF tracks in a single album: 8/16/

17 Here are the same DSF tracks transcoded to WAV: 8/16/

18 And here are the DSF vs. WAV bit-rates compared: 8/16/

19 Ways of playing a DSD computer file: In other words, the WAV equivalent of the DSF or DFF file has significantly more data available for the DAC to use. Importantly, this existence of massively more data is the main factor that distinguishes 192/24 files from ordinary CD files ripped to WAV. It is pretty tough for Less DATA to beat More DATA. c. Finally, we note that, as in the case of decoding DTS-HD Master or Dolby Digital TrueHD files, the computer is BETTER at CPU-intensive tasks such as decoding. Therefore, we would be wary of any claim that the relatively inexpensive chips within the DACs or Pre-Pros can beat the expensive multi-core computer CPUs when it comes to transcoding DSF to WAV or vice versa. 8/16/

20 A final word on DACs, DSD, and USB: The main benefit of using USB ports for hi-def music out of a computer is that the special software drivers used for USB do allow any sort of bit-depth or re-sampling rate. But there is a corollary -- beware of WHAT exact bit-depths and resampling rates your DAC can handle when using the DAC s SPDIF or AES inputs!! We have found that several DACs SPDIF inputs cannot handle a 192khz re-sampling rate, only 96khz. Similarly, some multichannel pre/pros have 2-channel AES inputs that cannot handle above 96khz. This is not a fault of the DAC maker so much as it is an assumption on their part that the original SPDIF/AES specs of decades ago still necessarily apply. SPDIF and AES were designed to receive a digital signal from a CD turntable, not a modern computer. Not all DAC makers have adapted their SPDIF and AES inputs to the new reality of powerful, current generation computers putting out 192/24 signals (or higher). 8/16/

21 A final word on DACs, DSD, and USB: A significant difficulty with this reliance on USB is that the vast majority of audiophile DAC reviewers believe that USB is the best output from a computer. Most of these reviewers NEVER audition the SPDIF or AES inputs of the DAC they are reviewing!! One reason is simply that their computers aren t set up to put out a 192khz/24-bit signal via SPDIF; or, the computer may not even have an SPDIF output (e.g., Macs); or the computer has only a stock shared RCA-TOSLINK SPDIF output (half the voltage). So when you read a DAC review, please check to see what the writer says about the DAC s SPDIF and AES inputs. At the very least, if he did not audition them, he should say it s because his computer is a Mac or a Windows PC using the USB output! 8/16/

22 What about the STORAGE of the digital file? Is one storage method better than another? An important point about computer audio is where should the large audio computer file be stored there are several options: 1. Within the computer on a spinning storage drive. 2. Within the computer on a Solid State storage drive ( SSD ). 3. Outside the computer on a USB-connected or esata-connected storage drive (spinning or SSD). 4. Via NAS connected by wi-fi to the computer. 5. Via NAS connected by Ethernet cable to the computer. 8/16/

23 What about the STORAGE of the digital file? Is one storage method better than another? SSDs are better than spinning drives because of lack of mechanical noise and better speed. But SSDs and spinning drives both generate EMI that can harm audio quality as the digital signal is sent to RAM to be played. For this reason, we insist on ONLY external storage. Most modern builds, including ours, use an internal SSD to run the complex software. We can t avoid that. And most modern builds also use a digital noise filter to reduce digital noise coming from the SSD. But very few true Audiophile servers will have data storage within the computer itself (only music servers will have internal storage ). External SSDs would be hypothetically better than external spinning drives, but SSDs are VERY much more expensive than spinning drives, AND ALL DRIVES will fail, it is just a matter of when. So, backing up your expensive digital data is PARAMOUNT. 8/16/

24 What about the STORAGE of the digital file? Is one storage method better than another? For the reasons on the previous page, we highly recommend the use of a NAS, with the NAS connected to the audiophile computer via CAT 7 Ethernet cable. CAT7 is more highly shielded than ordinary Ethernet cable, and thus protects even more against EMI. Connection to your data via Wi-fi is discouraged because all wi-fi routers produce drop-outs when going through the walls of a house. The Ethernet cable does not HAVE to be an expensive cable, but the better Ethernet cables (as long as they are Cat7 or better) can sound better. We think the point of diminishing returns sets in at around $100 or so (e.g., Audioquest Cinnamon). But, yes, with a great audio system (speakers, cables) the $200 Ethernet cable sounds better. 8/16/

25 How important is the digital signal cable going to the DAC? If you believe that all computers are the same (just zeros and ones), Then you will likely believe that all digital signal cables are the same. This is simply NOT true: 1. The quality of the SPDIF or AES cable is way more important than, say, the quality of the DC power supply into the computer!! [more on power supplies later] No sense buying an expensive DAC and Audiophile computer then using a $20 SPDIF cable. Spend at least $100, with diminishing returns not setting in until well over $600. We use $1400 digital cables in our own reference systems. Some of our clients use SPDIF cables >$5k. 2. The quality of the SPDIF or AES digital cable is more important than the quality of the USB cable for use with the USB DAC. Again, this view comes from our empirical testing. Hearing is believing. 8/16/

26 How important is the Power Supply Unit ( PSU ) for the computer? Most Audiophile computer owners will tell you that a Linear PSU (AC/DC converter) will REALLY improve the audio quality of the computer. Also, new generations of LiFePO4 battery-based PSUs also can significantly improve computer audio. But, always remember that what you are reading on computer audio websites pertain to the assumed use of a USB output on the legions of Mac-minis, MacBook Pros and regular Dell or HP laptops. 1. For these factory computers, the standard switch-mode PSU is REALLY lousy. So there are many models of linear PSU and batterybased PSUs that cut ripple/noise by one half or more. 2. But we have found that a very few makes of switch-mode PSU can provide essentially all of the audio benefit of the expensive linear and battery-based PSUs without the hassles (especially the price). 8/16/

27 How important is the Power Supply Unit ( PSU ) for the computer? 3. More importantly, none of the battery-based or linear PSUs now in wide-spread use, provide more than 7 to 10amps of DC power. This is fine for ordinary hi-definition 2-channel audio but is NOT sufficient DC power to do the following via a modern multi-core computer (without the PSU getting extremely hot): a. Rip and play Blu-ray concerts in Multi-channel and 1080p b. Transcode DSD to WAV c. Do the above while also employing cpu-intensive DRC 4. Moreover, our tests show that once the switch-mode PSU is sufficiently well made to reduce ripple/noise below about 10mv (compared to the 60mv or so of noise in the typical switch-mode PSU), spending more on the PSU does not reap anywhere near the benefits of improving the digital cable going to the DAC or pre/pro. 8/16/

28 How important is the Power Supply Unit ( PSU ) for the computer? For now, we continue to use a 16a switch-mode supply the best we could find -- coupled with a special pure-sine-wave uninterruptible AC power supply ( UPS ). The UPS is VERY important to protecting the sensitive motherboards used in an audiophile computer, plus the generation of the pure-sine-wave AC signal actually improves audio quality! You can choose to believe it or not, but the very best linear and batterybased PSUs do NOT significantly improve the sound of a best-in-class switch-mode PSU, when the switch-mode PSU is plugged into the pure sine-wave AC UPS!! Once you get to around 10mv of ripple/noise or less on the PSU, spend your money on digital cabling. That said, we are continuing to work with colleagues in the linear PSU industry to deliver necessary amperage in a new generation of linear PSUs. We follow our own advice -- never stop trying and learning. 8/16/

29 How important are the particular components used in the computer? We have tried to show that the important aspects of getting the best digital sound out of a computer are: a) The type of digital output connector being used; b) Whether the output connector is provided by a PCI card or is direct from the motherboard; c) The quality and versatility of the DAC being used; d) The specific way in which certain music file types are handled (especially with regard to DSD and Blu-ray music) e) Where the hi-def media files (the actual computer files) are stored. f) How much of the audiophile s budget is spent on digital cabling. g) How important it is to improve upon the noise of a factory PSU (AC/DC adapter); and h) How important it is to back-up your expensive digital media. If we have time, let s talk about the specifics of what might be inside the audiophile computer. 8/16/

30 How important are the particular components used in the computer? A. Should the computer be fan-less? B. Should the computer have an upgraded Word Clock inside? C. Should the computer have I 2 S capability inside it? D. Should the computer use one type of ripping software over another? D. Why, exactly, is JRiver Media Center claimed to be better than other media playing software? E. Does the quality of the optical drive used for ripping matter? F. Do details such as the brand and model of MB matter? The RAM? 8/16/

31 Should the computer be fan-less? Sure, the audiophile computer should be as quiet as possible. But what is the definition of quiet and is fan-less the same as quiet as possible? 1. Fan-less is not absolutely quiet the heat pipes send the heat to the fins, and this heat moves air. This can be measured on a digital sound pressure meter. 2. The objective should be to make the computer so quiet that, when playing, it produces no noise above that of the audio system on standby. This can be done with fans that are specially milled, so that the standard can be met at a distance of 1 meter or less from the audio system and the computer. 8/16/

32 Should the computer be fan-less? 3. But the next question is can fan-less be OK for a computer that is used to rip and play Blu-ray music, transcode DSD to WAV, and to use the most complex Digital Room Correction software? Or any two of these at once? The answer is a resounding NO unless you don t mind motherboard temps that approach 100 C!! Did you ever notice that the computer designers that use fan-less designs never talk about MB temps? And they certainly don t talk about Blu-ray music, or DSD to WAV conversion. How about ripping a Blu-ray while playing another? So the very best cooling system is a Hybrid system: a) Heat sink with heat pipes (often called liquid cooling because of the liquid within the heat pipes) for cooling the CPU, plus b) A Noctua exit fan cooling the MB and running at VERY low rpms. 8/16/

33 Should the computer have an upgraded Word Clock inside? Some computer audiophiles use special PCI cards with isolation and clock circuitry. Some of these PCI cards have an SPDIF or AES output, while some have a USB output. We have tried many of these during our long testing period before and after we came public. 1. The PCI cards that use USB outputs produce slightly better results than an ordinary non-dedicated USB output, but not as good as the best SPDIF/AES outputs, including those coming from PCI cards. 2. The need for clock circuitry (whose main job is reducing inherent jitter) outside the DAC is mainly due to the low quality of many DACs. Sorry, we re simply reporting the results of our tests. When the DAC itself is a good one, with the very most non-digital sounding DAC chipsets Burr-Brown (TI), Wolfson, Analog Devices, EMM, dcs we find that the PCI-based clock is no better, and in many cases significantly worse than, the DAC s own clock. 8/16/

34 Should the computer have an upgraded Word Clock inside? 3. What CAN sometimes help is a truly external Clock. Some of these brands include Antelope, Esoteric, and dcs. But prices are huge beginning at $5k for the Antelope and going up past $20k quickly. Meanwhile, the inexpensive external clocks typically do NOT improve the sound of a decent DAC. It makes much more sense, in our view, to upgrade your DAC rather than buying an external clock. In brief, the only consistent results we have are that clocks placed inside the computer do NOT produce as good a result with a decent DAC as the use of SPDIF or AES outputs coming straight from a dedicated header on the computer s motherboard. Clocks placed on PCI-cards inside the computer can sound better than the factory USB ports; but, again, not as good as SPDIF or AES straight from the motherboard of a 3 rd or 4 th generation multi-core computer with integrated hi-def audio on the MB. 8/16/

35 Should the computer have I 2 S capability? We are told that all DACs use an I 2 S process. So the question becomes why should that process reside within the computer rather than the DAC? We haven t seen any answer to that question, let alone an answer that makes sense. To say that this removes one less job from the DAC makes as much sense as saying the clock circuitry should be in the computer, not the DAC. Fortunately, this is a claim being made only by some makers of music servers, the ones that don t play all types of music. 8/16/

36 Should the CD ripping software be a particular brand? Many audiophiles use dbpoweramp ripping software. Mainly, this is due to its AccurateRip function. This routine literally double-checks Track 1 while the software is ripping Track 2. For most systems the result is not audibly better than using other ripping software (e.g., JRiver), but dbpoweramp is noticeably faster than JRiver, even when dbpoweramp is using secure rip. This software is our favorite. When ripping CDs there is also the issue of format e.g. FLAC versus WAV. FLAC is lossless but compressed WAV, and given the speed of the modern multi-core CPU, the difference in sound is not audible in most systems. Some of us perfectionists insist on WAV but the engineers say this is nonsense and the FLAC versus WAV issue is still in debate. This is not the first time I ve disagreed with an engineer. 8/16/

37 Why, exactly, is the JRiver software generally considered the industry standard? We are not software engineers so the answer is we don t know. But we do know the following: Most other pieces of software, especially the high-end servers proprietary software do NOT do the following: a) Play 2-channel or multi-channel audio from ripped SACDs or down-loaded DSF or DFF files. In fact, most music servers play no form of multi-channel music whatsoever. b) Play all audio formats AND all video formats. This is especially important if you like to watch a concert while listening to some of the very best 24/92 music available Blu-ray concerts. c) Transcode DSD music on the fly to PCM and then play the file over SPDIF or AES, not just USB. 8/16/

38 Why, exactly, is the JRiver software claimed to sound the best? We are not software engineers so the answer is we don t know. But we do know the following: d) Other software does not give you the flexibility of using Digital Signal Processing (DSP) if you wish, or NOT. This includes the potential for some of the very best Digital Room Correction software (DRC). Bit-streaming with no DSP is NOT always the best choice. Let the computer do what it is good at, and do NOT let the DAC or pre-pro do what it is bad at this includes: Any kind of transcoding or decoding, including decoding of DTS or TrueHD; transcoding from DSD to WAV (PCM). Equalization or time domain corrections in the digital domain. Down-mixing of multi-channel files to 2-channels (or viceversa). 8/16/

39 Why, exactly, is the JRiver software the industry leader? 2. What about add-ons to JRiver? We have tried almost everything touted on the audiophile computer blogs and forums; most of these add-ons don t improve audio quality in our reference systems. Some hurt audio quality in a good system. Please don t believe everything you read on the Internet. Sorry, but if you want to improve the sound of your system (but keep your speakers and cables), then buy a better DAC. We are especially critical of the many inexpensive DACs that use DAC chipsets that sound tinny in our own systems. Having a budget to meet is one thing, but please, don t rely on a DAC review in which the reviewer uses ONLY the USB input of the DAC, or implies that the $400 DAC is the equal of a truly good DAC costing several thousand dollars. 8/16/

40 Why, exactly, is the JRiver software the industry leader? 3. Please remember the results of the basic empirical work We have done: All DACs in the world are DSD-capable, since any computer can use JRiver to transcode DSD to PCM. Depending on the DAC, this may sound significantly better than DoP or native DSD. The term DSD capable is little more than a marketing ploy for all the new DAC makers out there. And while we re at it, remember: The DAC, in our experience, is almost as important as the speakers and cables, and way more important than the player or server. It makes little sense to buy a very expensive server if you are not prepared to buy a truly good DAC. For the vast majority of DACs out there, you should continue to use your Dell or Mac laptop. 8/16/

41 Does the quality of the optical drive used for ripping matter? We have not found that the quality of the optical drive matters when ripping CDs with dbpoweramp. But it does matter when ripping Blu-ray discs. We use the very best Teac drive (Japanese made) in our upper level models. More importantly, we advocate ripping the Blu-ray disc to the internal SSD rather than to a spinning storage drive. This eliminates video anomalies that might be due to variations in the spin speed of the rotating storage drive. But then you must copy the ripped file to your storage drive and delete it from your expensive SSD so that there is then room for future rips. Only the most demanding videophile needs to do this (I don t), but like most of high-end, everything makes a difference. 8/16/

42 Do details such as the brand and model of MB matter? The RAM? If you think that all computers are the same then you won t believe our answer which is YES! But then, why are you in this seminar? We won t go into details here other than to say that some MBs sound too digital to us, in our systems. Similarly, some brands of RAM don t seem to sound sufficiently analog to us. We think that for the vast majority of audio systems, these details do NOT matter. But for some of the very best systems they certainly do matter. To repeat the quality of the digital cable is EXTREMELY important, once you get past the mental block that USB is the only way to play music from a computer. 8/16/

43 Thank you for listening. Now, the required legal disclaimer: We build computers that use Windows operating systems. We do not build any software whatsoever for the computer, nor do we install any unlicensed decryption software. We do not condone any illegal copying of media. We are not lawyers and cannot advise you on the legal consequences of copying CDs, DVDs, or Blu-ray discs even for your own personal use. We concentrate only on making the best Windows computers that produce the best audio and video quality from any legally obtained source material such as legally downloaded 2-channel or multi-channel audio files, or legally obtained audio-video computer files such as those that might come within a retail Blu-ray package. Copyright 2014 Baetis Audio - All Rights Reserved 8/16/