Do Transports Matter--or are bitses bitses?

[The Monkey]

I was always under the impression that so long as you got "bit perfect" out to your DAC, it was all good. Is this true? Am I dumb? Learn me.

[manaox2]

But... but... the jitter... and the connectors... impedance...

[The Monkey]

Yeah, that's what I think. Fuckin' jitter can go to hell. I thought most modern DACs were "immune" to jitter.

[Voltron]

Jitter in the Shitter in 2011!

[deepak]

The world ends in 2012 jitter is the least of our worries!

[The Monkey]

I guess if we have jitter then the terrorists have won.

[Dusty Chalk]

Yeah, that's what I think. Fuckin' jitter can go to hell. I thought most modern DACs were "immune" to jitter.

Well, if you believe in jitter, then no. Most DACses use a PLL to sync to the incoming signal, so they'll still fluctuate some.

Now, whether or not you believe in jitter, and (as is the case with me) if you do believe in jitter, but are skeptical you can hear it, that's something else entirely.

So in answer to your question, the transport should only matter if you believe in jitter. Or the digital equivalent of wow and flutter.

Addendum: it might also matter if you believe that your source doesn't produce a 100% match of all the bits (I.E. errors).

[Fitz]

it's almost 2011, after all.

according to dom its already 2011, if you trust his perception of time that is

[deepak]

we can only hope that we have that long.

I am thrilled and...terrified

[aardvark baguette]

Dr. Gillian Taylor used Kirk's transporter without any downside, so I think they're all the same.

[n_maher]

Having been down the transport rabbit hole to some degree I tend to consider them to only be potentially influential. By doing so I try to use something decent (e.g. not a $50 DVD player) but will not go to the extreme of using some $5000 super suspension system insanity.

[aardvark baguette]

The old boombox I used to have made a constant whine noise. Alot of players now use CDrom drives, and I know I can definitely hear my computer drive spin up and down, so there must be software trickery or noise dampening going on in the nice ones. I can't hear it in my XA5400es, except slightly when you first put a disc in. But I'd bet the sound you hear or dont hear from the drive outweighs jitter by several orders of magnitude in regards of a cleaner sound.

[swt61]

I have owned and tried several different transports. Short story...They all sound a little different.

The differences have been fairly minor, but I agree with Nate completely, and wouldn't spend megabucks or minibucks. My current Parasound C/BD-2000 belt drive transport is my favorite transport to date. I like it better than an expensive Levinson unit I listened to. It's heavy as all hell too.

[digger945]

Dinny, it's not that the transport sends a 01110010 and the dac gets something else. Obviously we hear a good sound out of the dac, so it's getting the right information. According the the jitter crowd, it's the timing of said bits, as sent from the transport, and along the way, and hence all the talk about clocks and coax, etc. The computer and transport crowd are trying to do the equivalent of adding a heavier flywheel and smoother motor drive to the turntable. Large variations in timing could be interpreted by the listener as the same thing as randomly moving the speaker back and forth, closer and further away from the listener. Because all the digital information for both channels is sent "one after another" in a serial fashion, then small timing errors could also change the stereo image.

Could means I don't know, that's what I have read and studied. From time to time.

[deepak]

I have heard a difference between the Lynx AES16 and an M-Audio Transit as digital transports. The price gap between the two is huge so I stick with my Transit until I can build a silent PC for the PCI card.

[atothex]

I consider myself to be a believer, and it seems that computer transports improve by leaps and bounds up to maybe $300-ish, which is the price of a used pro sound card or Squeezebox. I definitely think i heard a significant difference between my current sound card and previous ghetto setup of running straight from my motherboard.

I think one can comfortably top out at the totl Lynx or possibly Transporter at around $1k and call it a day forever. I guess those super stacker players from like dCS/MSB/Spectral/whomever are supposed to be slightly better, but that is sooooo much more money. I can think of like infinity things I'd want before getting one of those transports.

[Tyll Hertsens]

My first ever double post.

Feeling a little jittery, are we?

[padam]

Yes, switching to a Halide Bridge made a big difference to the overall sound even if the amp I use is a temporary solution.

It especially matters with something like an O2 MK1 717 combination, a good DAC is not enough.

[jp11801]

I don't know why they matter but they seem to. SIburning did a transport shootout with a portable dac at a NY meet and the differences were pretty stark. Yeah I know it is not the best or even a good test environment but the differences were there. It suprised most of us that participated.

I've not heard a good usb to spdif yet but I only dabbled in the $100-$200 group. The trends and hagusb had the effect of rolling off the leading edge of the notes the attack sounded muted compared to optical out of a my mac

[jpelg]

Not sure that jitter is the, or the only, culprit for differences.

I once compared a portable Sony PCDP with optical-out with another Sony model (also portable, also optical), and there were easily detectable differences in the output levels. A full-sized home CDP was still different. Each increasing in output level respectively. This was using the same DAC with its own internal headphone amp, and the same headphones.

Since the digital output on all of these players is not variable, I can only assume that the players' internal software that controls the digital signal is preset at a certain output level. I can also reasonably assume that other digital-outs are also not equal. Don't know how you measure that though. Also don't know if this occurs when using coax/RCA-type digital connections (or any others, for that matter). But I bet that that this accounts for more differences between transports than jitter.

Benchmark also did a comparison between a small sampling of DVD players as transports, with considerable differences between those used. But this mostly had to do with sample-rate down conversions at the digital-out side even if the players' DAC chipses could read a higher-level signal. Of course those player/transports that preserved the full sample rate sounded better.

[bozebuttons]

I don't know why they matter but they seem to. SIburning did a transport shootout with a portable dac at a NY meet and the differences were pretty stark. Yeah I know it is not the best or even a good test environment but the differences were there. It suprised most of us that participated.

That was my Theta Data Transport at the NY meet.I find dedicated transports work better then DVD players,modded ,portable or stock.

My CDSD transport was a big improvement over the origional emm labs modified phillips Sacd 1000 using my Dac6e.

[regal]

Having been down the transport rabbit hole to some degree I tend to consider them to only be potentially influential. By doing so I try to use something decent (e.g. not a $50 DVD player) but will not go to the extreme of using some $5000 super suspension system insanity.

Being an engineer I never went down the transport rabbit hole, but recently have experienced significant SQ differences with different USB transports, especially when I modded my Hiface to batteries. Got me thinking the EE's may be missing something. Tried to measure the differences with FFT software but nada so it could be placebo but sure doesn't sound like it comparing the modded Hiface with a TerraX. Then there is Jocko's USB transport that he posted a 3ps measurement of for only $500 which I haven't tried.

Still I have been eyeing $3-$5k transports.

Are you saying this is big waste of money? What about Steve N's products ?

[Dreadhead]

my 2cents:

If the transport is bit perfect then the only thing left is jitter and the easy way to check to see if the transport is bit perfect is to have a DAC with a HDCD light and an HDCD in the transport. There are other ways using recording software and any bit perfect recorder with software but they are a PITA. With high levels of jitter (be it poorly clocked, or a poor transport) with older non-independently clocked DACs then it's probably audible but the question was with modern DACs and there I believe that in general bitses are bitses.

That said if it the transport is not bit perfect (a lot of DVD players for example) then there can be huge differences in volume control, filtering etc. I can never quite figure out why some USB transport manufacturers decide not to do bit perfect but they do and include all sorts of upsampling, downsampling, brick wall filtering, minimum phase filtering etc.

Also with older CDs that were less than perfectly mastered bit perfect will actually sound worse than something with a minimum phase filter because of the effects on the transients. That's what Ayre's "listen" filter does.

[swt61]

While your logic seems sound, I've experienced different sound characteristics in bit perfect transports. That's head to head and not from memory. I don't care to hazzard a guess as to what's happening, but it wasn't in my head. So there must be something else at work here.

[Dreadhead]

While your logic seems sound, I've experienced different sound characteristics in bit perfect transports. That's head to head and not from memory. I don't care to hazzard a guess as to what's happening, but it wasn't in my head. So there must be something else at work here.

Was it at least single blind, volume matched, and are you sure that they were truly bit perfect or just claimed to be bit perfect?

It's a pretty common trick to pump up the volume 2/3dB which will sound "better" but will not be that noticeably different. I don't trust my ears anymore on volume matching and use a voltmeter across the headphone out along with a test tone.

I was absolutely 100% convinced I could hear the differences between my two DACs at regular listening volumes until I did a couple single blind tests and couldn't tell shit with any accuracy.