pc based audio

Hm, well, I recovered from a crash due to fooling with the settings and now it seems to be fine.

Oh, how glorious this stuff will sound with a Bottlehead DAC and my SEX!
 
Hi everybody,

I'm fairly new to the BH family - I just built a Crack over Xmas break - but I have some ideas here.  I'm an engineer, and I've spent 22 years with Autodesk, Inc. in various roles.  I'm primarily a music lover, and I'm fascinated with the concept of music reproduction.  I recently (two days ago) changed "The #1 Wish in my Life" from driving a factory Porsche GT3 at the Nuerburgring (which was never going to happen) to getting my hands on a production BH DAC... pretty messed up, eh?

Regardless of my weak qualifications, I have spent a couple of years building several pc-audio systems, and I think that I've learned a lot.  I know nothing about vacuum tube circuit design, but I think I understand PCs.  So, here's a synopsis:

1.) Analog audio out of a PC is... bad. You can imagine all of the schytt that's going on inside of that box. PCs are Ghz-frequency digital devices, and - amazingly enough - the noise/RFI generated inside of the PC is of little consequence to the digital circuitry inside.  It's either a zero, or a one... and it's fairly easy to make that determination in the digital domain.  In the analog world, however - all that RFI is just radiating, looking for an "antenna".  Your analog audio wiring inside the box looks a lot like an antenna, BTW.  I know that you're all aware of the limitations of analog audio from a PC-source, as you are all Bottleheads... so enough on that subject.

2.) USB was NOT designed to carry music.  I am not an EE, I was trained as a ME... however, with 20+ years in the industry, I understand the difference between data and music.  Data is, just that - get my zero'es and one's resolved, and I'm fine - I will have data integrity.  On the other hand, digitized music is a slave to the 4th dimension - time - and, if you don't pay attention to that requirement, even your digital streams are going to sound like they've originated from a PC.  This timing issue can be ameliorated, but it takes either a.) a schytt-load of cash or b.) some ingenious software.  More on that to come...

3.) Harry Nyquist (and Claude Shannon) was (were) wrong - at least as far as music is concerned.  Their sampling theorem might hold true for data - in that case, the concept of the data being "completely determined" by a [max_freq]*2 sampling rate is valid and has been empirically proven.  But shuffling bits from one place to another has nothing to do with music, and that's why my loving-yet-tone-deaf wife can easily tell the difference between a CD and a high-rez (24/96 or higher) bit-stream, without being prompted...

So, as any engineer would approach this.... "how to fix?"  Indeed, it's not as hard as they (the audio press) would want you to believe. I have nothing but respect for the editors of Stereophile (I've been subscribing for.... 15+ years?) and The Abso!lute Sound...but the true solution to the problem is not based on throwing money at it.  It's about being smart, and working to understand the issues at hand.

[BTW, my friends:  it's Friday night, I've had a coupla brews, and I'm listening to Janet Jackson's "Rhythm Nation 1841" via a FLAC stream from my HP workstation... bitperfect (via ASIO) digital out to a marvel of price/performance:  the Pro-Ject USB Box.  Analogue voltage swings exit the Pro-ject via AudioQuest Black Mamba II cables (BTW, the concept of 'cables' will be the subject of another rant, RSN) to my beloved, hand-forged Crack.  :-)  The modulated audio signal causes current to cascade across that workhorse 6080 (and it's such a pretty tube!), inducing voltage-swings that are transmitted via the (marginal) stock cable, into the drivers of my 1,000+ hour Sennheiser HD-600s... did I say that 'Life is Good'? I'm 52 years old, and I'm chair-dancing to Michael Jackson's sister's worst album... auch du lieber, Augustine!]

But I digress.  Doc, I promise to get my 'script refilled tomorrow... I promise.

I'll be really honest:  if $$$ were unlimited, I'd buy all my music in highrez from HDTracks.com - OMG, I've always loved Alison Krauss, but "A Hundred Miles or More - A Collection" will stop your heart... and no, Doc - I'm not talking about two hands in the B+ power supply.  I'm talking about plain 'ol LOVE.  The girl is an angel...

And then... I'd listen to those 48k/24-bit (or higher) bitstreams via a dCS Puccini U-Clock, because it's the most incredibly-stable DAC out there... [Doc, Paul... I know that you guys can do better...  ;-) ]  But, I have two kids in college and a wife.  So, no U-Clock, and... what the heck to do with these 800+ Nyquist-theorem-crippled 44.1khz/16-bit CDs?

I have three systems in the house.  Two are purely digital in terms of input; both are driven by PCs.  Both sound amazing, IHMO.  I promise to tell you guys more about what I did, and how I did it, if you're interested.  Let me know, OK?

And Doc... how's that DAC coming?  I'm on the order list as soon as you announce...  :-)

Thanks for putting up with me,

-don

 
Sounds like you'll fit right in around here. But chair dancing to Janet Jackson, now that is cause for concern. You steadied the ship with Alison Krauss though.  BH is a true value in this all to often over priced audiophile endeavor. None the less I'm along for the ride and BH has yet to disappoint. I'm also interested in a pc based system and am currently looking at building a music server. I've rolled it over so many times I'm gettin nauseous. Time to bust a move on it soon but for now,
Ich mus eine Heineken trinken
John
 
Hi don,

I don't mean to sound snarky, but there are lots of myths, half-truths, misinformation, and even some dysinformation concerning computer-based digital audio  out there.  Also, this is in no way meant to criticize bottlehead as hardly anybody outside BH has heard their dac so far.  That said, a few things...

usb, when ddone right (and that does not mean async necessarily) is perfectly suitable to superb digitial playback.  Secondly, there are a huge variety of asio drivers, and none of them can gurantee bit-perfect playback as there is much much too much going on inside the PC, even when carefully stripped downwith nLite) to guarantee bit-perfect playback.  I also don't agree that it takes tons of money to get superb playback, but software can be a very important part.  After loads and loads of experiments by myself an friends, it is clear that a windows based transport is in third place witha single-board linux box in second place and a tweaked Mac Mini, clearly ahead of everything out there atthis time.

Also, spdif is full of compromises and is far more difficult to get a quiet, clean data stream out of.  How do I know this?  Well, like you, I am 52, an EE/CE and a 40 year audiophile, but all that aside, it is because I am listening to a usb-only, 16/44.1 only dac connected to a modified Mac Mini as transport, and for the firstime in my life I am hearing the real promise of digital in a completely, grain-free, glare-free, dynamic, extended, detailed,and completely enchanting way.  The dac in question is less than $2k, is a NOS chip, has no async usb interface, nojitter reclocking circuitry, no tubes -- just a power indicator light, an iec power inlet, a usb B data connector, and two rca outs, and cost less than $k (currently, but going up at the end of the month.)

There is absolutely nofatigue at all with this dac, and I have listened (to plain-jane 16/44.1 cds for 10 hours straight and could have kept going.

This dac asympotitically approaches vinyl, but has overall dynamics, and maye even more importantly, dynamic contrass to die for and that you'd have to spend an executive's yearly salary on an analog setup to even start to come close to.

I've heard many many dacs of all kinds, with all kinds of transports, and at all price level imagineable, and to my mind, this is the one to beat.

I too am looking forward to the BH dac, but it's going to take some amazing engineering to outclass this one I'm talking about.

This is the dac that shattered all the myths about usb and the limitations of 16/44.1 and affordability.  It really is the game changer to pay attention to if you are considering and/or designing a new dac.

-- Jim


P.S. -- welcome!

 
and that DAC is ... the HRT MusicStreamer II+ ? That's less than the cost of the Seduction.

Listen, I understand next to nothing of the technical talk. This is not my field. But I care deeply about getting the best out of my music, and feel that I can hear the differences.

With digital it gets tricky. I have a lot of FLAC that I've downloaded and a lot of my own collection ripped to FLAC. Loaded in J.Rivers Music Console these files are easy to access and sound relatively good. I'm running Vista and have a Juli@ installed. It is doing the dac, so that I'm outputting analog. Now I know it would be ideal to get an external DAC, but I don't have the funds yet.

I listen to my CDs and SACDs on a Denon 2930CI. I haven't yet compared the two, but I suspect the Denon sounds better. Once I do the dac externally, however, they should sound identical, right? The catch is SACD, which I don't think can be output digitally (on this machine). So I let the Denon do the dac, but then I'm short-changing myself, or?

(Addendum: actually the Denon does output SACD digitally through the Denon Link, only compatible with Denon receivers. It would be great if this signal could somehow be converted into one recognizable by a standard DAC.)
 
Well, I didn't really want to mention it on the BH forum, but since somebody asked, I'll mention it this once...

it's the db audio labs Tranquility SE.

I also am generally really rserved when it comes to talking about audio products as I know there are such huge variables in our systems, rooms, tastes, and budgets, but I'm definitely not a wealthy person, but music and audio are my number one priority after my wife and our critters, and as a blind person,it is probably more important to me than most as it is the most powerful way I connect with the emotional/sensory world.  I'm also not easily impressed.

-- Jim

 
Hi Sam - I don't think that anyone has come up with a consumer-friendly way to get the digital bits off a SACD.  Unlike CD, the SACD data is stored on disc, and delivered to the player's digital processing chain, as an 1-bit Direct Stream Digital bitstream at 2.822 Mhz.  There are several pretty heady physical copy protection features that prevent this data from being ripped, including an encryption key that's located on the disk in a physically inaccessable area - except to a licensed SACD device.

And even if you could get the bits off the disk, conventional DACs can't decode the encrypted, delta-sigma modulated data.

So, I would say: don't stress on which DAC might be better; we have an older Denon DVD/SACD player (DVD-2200) in our surround system downstairs; it sends multichannel SACD audio out to a Sherbourne pre-pro via six unbalanced analog (RCA) outputs (5.1 channel), and it sounds fantastic.  I know that SACD sounds wonderful - my desire is to get as close to SACD sound as I can with the 800+ CD discs that are hanging around the house.

I would say - enjoy those SACDs as played by the Denon; I know that mine sounds really great - and as you've said, probably better than your music server.

Thoughts?

-don
 
jrebman said:
Hi don,

I don't mean to sound snarky, but there are lots of myths, half-truths, misinformation, and even some dysinformation concerning computer-based digital audio  out there.  Also, this is in no way meant to criticize bottlehead as hardly anybody outside BH has heard their dac so far.  That said, a few things...

usb, when ddone right (and that does not mean async necessarily) is perfectly suitable to superb digitial playback.  Secondly, there are a huge variety of asio drivers, and none of them can gurantee bit-perfect playback as there is much much too much going on inside the PC, even when carefully stripped downwith nLite) to guarantee bit-perfect playback.  I also don't agree that it takes tons of money to get superb playback, but software can be a very important part.  After loads and loads of experiments by myself an friends, it is clear that a windows based transport is in third place witha single-board linux box in second place and a tweaked Mac Mini, clearly ahead of everything out there atthis time.
Click to expand...

Hi Jim,

I don't think that you have a snarky bone in your body, sir.  I realize now, after re-reading my email from last night, that I could have been a bit overenthusiastic (read: inebriated) regarding friend's hardware that I have heard, and the virtues of high resolution audio files.  Thank you for your patience with me, I'm new here.  And thanks for the welcome, too.

Regarding USB for audio, I actually downloaded and read a fair amount of the USB Device Class Definition for Audio Devices today (yeah, I'm a bit weird).  Also interesting that Release 1 of that doc was dated 18 March 1998... not nearly as old as the CD-DA standard, for sure.  And you are 110% correct - USB _was_ designed with high quality audio in mind.  From the Management Overview section, pp17:

An essential issue in audio is synchronization of the data streams. Indeed, the smallest artifacts are easily
detected by the human ear. Therefore, a robust synchronization scheme on isochronous transfers has been
developed and incorporated in the USB Specification. The Audio Device Class definition adheres to this
synchronization scheme to transport audio data reliably over the bus.
​

So what I'm reading here - at the risk of oversimplification - is that the USB standard supports high-quality audio, but very few have built software that takes advantage of this capability.

Hmmmmm.  Sounds like an opportunity.  In the meantime, those of us who don't have the right chops will be stuck with S/PDIF, I think.  I totally welcome a USB audio implementation that sounds correct.  If someone could build it at the "right" price-performance point, they'd be overwhelmed with orders.

That being said, Jim - I still think that the 16-bit / 44.1khz standard for CD-DA is flawed - but then, the Red Book was first published in 1980.  I guess that my real issue (and I know that you got this) is what I said in italics near the bottom of my rambling:  "...what the heck to do with these 800+ Nyquist-theorem-crippled 44.1khz/16-bit CDs?"  I think that the solution looks like this:

1.) bitperfect FLAC rips of CDs (with a tool like dbpoweramp)
2.) bitperfect output from the pc to the DAC - (USB, S/PDIF... don't care - as long as it's correct)
3.) time-domain coherency in the reconstruction of the audio waveform and
4.) enough amplifier power to drive the transducer of choice

I think we got #1 and #4 nailed.  Still waiting on #2 & #3. 

I've been applying "gearhead techniques" to this problem here at our Casa - mainly because I'm a gearhead, and that's all that I know.  I'll have to rely on folks like Doc, Paul J, Paul B, Grainger and others to come up with an elegant solution to the task of converting 1s & 0s to smooth, spacious, grain-free sine waves at a price point that I can afford.  And, if it's a kit that I can actually build, it'll be awesome.

Thanks again, Jim.  Great to meet you!

-Don


 
dstrimbu said:
...I'll have to rely on folks like Doc, Paul J, Paul B, Grainger and others to come up with an elegant solution ...
Click to expand...
Don't leave out John Swenson, who has been spearheading the digital portion of the DAC we're working on. I've played with digital acoustic data for more than 30 years professionally, but I turned down that job - John is way more qualified, knowledgeable, and talented. I'll just work on the tube/audio parts.
 
Yup, John Swenson is absolutely not to be left out of these conversations. He is the most knowledgeable of the folks who have worked on this project when it comes to the digital realm and that aspect of the design is definitely contributed by John. PJ and I have been discussing some new ideas for the analog part of the D/A, and we will be testing some theories over the next month or two, with PJ leading that part of the development. I know some of you guys are champing at the bit for the DAC. My job is to decide when we need to do just a little more experimentation to get it the best we can before going into production. Right now we are in one of those phases where we may have a new idea that can give us another nice jump in performance, with the added bonus of a bit less cost. That makes it easy for me to say we need a little more time to get this thing the best we can.
 
dstrimbu,  you mentioned in your post below a program called dbpoweramp for making bitperfect FLAC rips of CD's.  I have heard of and was wondering if you have tried EAC (Exact Audio Copy)?  I was just curious how they compared.  I would like to rip my CD collection and want to use the best program and I am definitely not an expert at this at all.
Thanks,
Dave
 
Hi Xavier,

A couple of things...

I've owned both the Proton and the Cosecant -- with both the high-res and NOS dac modules, and the cosecant is way better than the proton, but that doesn't mean the proton is a bad dac.  Also, neither of those live here anymore because I was able to do a side-by-side comparison with my current dac, and again, there was no contest.

With regards to processing power, there is actually a point of diminishing returns as once you have enough power to move bits out the door (and this can be easily improved with any given computer by shutting down background process and other things that could grab the processor's time), any processing power above that is just additional RF energy that invades the circuitry and has the potential tointerfer with the signals.  Also, with laptops, you can never get too far from the display hardware, and this seems to be one very large contributor to digital noise and interference, again lowering the quality of playback.  I run the Mac mini headless and use a remote app on an iPod touch to control it, which also lets me turn off the bluetooth and IR ports, which add another step in improvements.  This stuff is criticaly sensitive to absolutely everything, and especially the AC power fed to the entire digital chain, the cablinhg -- there's a huge variability in quality to be experienced with different usb cables, firewire cables, etc.  If I had not done these experiments for myself, I would be skeptical as any normal engineer would be.

Increasing memory is typically a good idea, but again, only if your playback software can support truly track-buffered memory play, which most sofware out there can't do.  The speed of the external HD is also another factor, and the 5400 rpm drives typically sound better than the faster 7200 ones, and the firewire chipset in the drive can also have a pretty noticeable effect, with the Oxford 934 chipset being the current go-to unit.

So, the point here is that it's great that you did a comparison, I think if you're going to compare a sota turntable and R2R unit to a computer-based dac as source, you really should strive to do more of an apples to apples comparison.  Of course, I can understand why you can't do that as this stuff, at this level, whilee not cheap, is typically not as expensive as a similar level TT or R2R setup.

I have been underwhelmed by most dacs, even expensive, high-res ones for years, but for me, the major concen was the convenience of access to my music, which as a blind person, and a sizeable music collection, was getting unmanageable.

It was less than a year ago now when the predecessor to my current dac came out, and that's when things really started to happen.  I've played with windows boxes of various kinds from laptops to htpcs, to single-board linux boxes (very, very good and quite inexpensive) and finally in October, I took the plunge and joined the mac world and that was the quantum leap to the entire system that took it up to a level where I am now, which is further than I ever expected to be, regardless of source type.

Friends come by and listen, some very hardcore audiophiles with nothing but analog setups and are simply stunned to silence, especially the ones whose systems cost more than an order of magnitude more than mine.  When that happens, all I can think is that I must have done something right -- if the people who have been fairly critical of my system (as polietely as possible) leave here shaking their heads, well, maybe I finally feel vindicated :-).

So there it is -- a computer, usb dac (16/44.1 only), a custom LDR attenuator, a pair of 3 watt direct-coupled amps, and a pair of speakers with 8 inch main drivers and a ribbon tweet, copper cabling, no power conditioning (yet) and I'm living large.

Best,

Jim
 
AudioDave said:
dstrimbu,  you mentioned in your post below a program called dbpoweramp for making bitperfect FLAC rips of CD's.  I have heard of and was wondering if you have tried EAC (Exact Audio Copy)?  I was just curious how they compared.  I would like to rip my CD collection and want to use the best program and I am definitely not an expert at this at all.
Thanks,
Dave
Click to expand...

I used to use EAC extensively before trying dbpoweramp. I liked dbpoweramp so much, I bought it within about 20 minutes of use; same functionality, but in a *much* more user friendly and stable package.
 
Beefy said:
AudioDave said:
dstrimbu,  you mentioned in your post below a program called dbpoweramp for making bitperfect FLAC rips of CD's.  I have heard of and was wondering if you have tried EAC (Exact Audio Copy)?  I was just curious how they compared.  I would like to rip my CD collection and want to use the best program and I am definitely not an expert at this at all.
Thanks,
Dave
Click to expand...

I used to use EAC extensively before trying dbpoweramp. I liked dbpoweramp so much, I bought it within about 20 minutes of use; same functionality, but in a *much* more user friendly and stable package.
Click to expand...

Thanks Beefy, you beat me to it.  Dave, EAC was a bit iffy on my Win 7 machine; dbpoweramp is much more stable and easy to use.  I bought a license the next day... its that good.  You won't regret it; ripping CDs is a boring process and making it foolproof the first time was critical to me.  I actually went back and re-ripped several hundred discs that I had previously ripped with older versions of MediaMonkey.

-don
 
Thanks for the replies guys,  I checked out dbpoweramp and I agree it is much easier than EAC.  Thanks for the suggestion!
Dave
 
xcortes said:
So here I go, a Proton and a new, dedicated, Macbook Pro (there's consensus that the more processing capacity of the machine the better it will sound).
Click to expand...

This was a very valid statement a few years ago, but with the continual increase in processing power you could get away with using a MacMini as your dedicated audio computer. Kind of hate to waste the beautiful LED screen on just music. Besides, the Mini has basically the same processor as the MBP's except you cannot boot the newer one's into 64-bit mode without doing a firmware hack that will nullify the warranty.
 
Hi Yoder,

Don't get me wrong, the MBP makes a very nice music player, but the mini is really the superior machine for this purpose -- when given the full treatment of OS tweaks, music drive on a different type of interface than the dac, maximized memory, SSD, 64-bit mode, hogmode enabled, etc.

Also, try flipping the power cord on the mini and you get asomewhat different presentation -- more dynamic and detailed in one orientation, more warm and smooth in the oother.

Next up will be my new linux box with voyage linux .6 and the latest version of MPD, all controlled from the MPoD app on an iPod Touch...

-- Jim


I just tested two identically spec'ed mcs -- a 2010 mini w/8gb ram and 2.4 ghz processor and an MBP with same ram and processor, and the mini is the clear winner and by a substantial margin.  But there are some other factors to consider -- the mini is running headless with no display and only a usb keyboard and has a fully tweaked operating system (that does indeed boot into 64-bit mode) and the MBP is stock with all my working software installed on it.  both machines have SSD drives, and both used the same external firewire 800 music storage drive.  Both machines are also running the same playback software -- latest version of PureMusic
 
jrebman said:
Hi Yoder,

Don't get me wrong, the MBP makes a very nice music player, but the mini is really the superior machine for this purpose -- when given the full treatment of OS tweaks, music drive on a different type of interface than the dac, maximized memory, SSD, 64-bit mode, hogmode enabled, etc.

-- Jim
Click to expand...

I think you misunderstood me, I am for using the MacMini as a music server in place of a MBP, and have one performing such duties in my home while the 17" MBP is used for other duties. If you are using a new Mini, then I am curious how you got it to run in 64-bit mode without violating the warranty. I don't know why Apple won't give it 64-bit capabilities like the server has, but you cannot boot in 64-bit mode without hacking into the firmware. I have filed my concerns with Apple, but I doubt if me little voice will have much impact.
 
Hi Yoder,

I don't know how the guys at Mach2 Music did it, but it does run in 64-bit mode.  Not sure if this is on even newer minis, but mine was purchased directly from Apple last September.  I think there are 3 significant differences between my mini and MBP -- the mini has the highly tweaked OS and launch scripts for the music players, the power supply on the mini is better (even better sounding than batteries on the MBP), and the lack of a LED screen, which really does seem to introduce some nasties in the system.

I've also used the mini without the OS tweaks, and the sound is much closer to the stock MBP, so reducing the OS overhead and the launch scripts that shutdown all unnecessary processes just before the music player apps run, is also very key to the sound.  In fact, it is very easy to just launch the apps without the scripts and even that is a very noticeable difference.

So, the mini is cheaper,, can run without a display, is silent with an SSD, can use after market power cords if desired, is smaller (in terms of typical audio rack real estate) and is super easy to upgrade the memory on.  This system as it is now is right up there with some of the cost-no-object transports and dacs, and is far more convenient (once setup, that is.)

Back to your original question/concern -- it came with the software tweak package, and if something goes wrong, Mach2 Music will take care of it, I'm sure.

I'm a relative Mac newbie, so I really don't know all the ins and outs of the OS and aside from some basic tweaks to improve music player performance (which are all documented all over the internet) I wouldn't dare go hacking the kernel or anything else myself.

-- Jim
 
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