why do transports sound different?
Feb 7, 2010 at 3:52 AM Post #16 of 177
What Hi-Fi put 3 music lovers in a room last year and played the same selections (mainly classical) through 3 separate rigs into the same DAC:

1. ipod+ND-S1 Onkyo transport
2. CDP
3. Computer hard disk

Without wanting to get bogged down in the specifics of the kit involved, all 3 rated the ipod-based rig as their least preferred, one opted for the CDP and the other two were most impressed with the computer transport. Probably a bit convenient when it supported WHFs earlier contention that the ND-S1 wasnt on a par with an entry-level CDP, but I was surprised by the extent to which each of the test subjects reported major differences between the 3 rigs. Same DAC, presumably the same cables etc.

The debate over jitter levels, RFI and DBT wont go away anytime soon, but i'd definitely like to be part of such a panel, preferably with music more in line with my own preferences.
 
Feb 7, 2010 at 5:31 AM Post #17 of 177
I was using an optic cable, so RFI shouldn't matter that much.

Both the C601ES and CA70ES have only one circuit board, signal ports are at the same location, and the power transformers are at similar location too.

The good thing about a seperate DAC is that you can do very fast A/B'ing, I put identical CD's into both players and use the remote to start the same song on both machines at the same time. switching between transports take less than 3 seconds (unplug/plug the optic cable), so the sonic memory should be very fresh.
 
Feb 7, 2010 at 5:45 AM Post #18 of 177
yep, jitter, power supply, clocking and cables (related to impedance mismatch/jitter), clock only if the transport is actually producing a clock that is used rather than thrown away with ASRC. even if the stream is reclocked there is a certain amount that will make it past most jitter rejection and be incorporated into the signal, ASRC is the only way I know of (apart from slaving the transports clock to the dac) for the transport to have nothing to do with the sound IMO.

but yes its a squishy squashy area that has its heart down at a level we really havent got our heads around just yet, there may well be an entirely different phenomena responsible for jitter
biggrin.gif
the area needs more study
 
Feb 7, 2010 at 8:08 AM Post #19 of 177
IMHO, jitter is actually irrelevant IF your DAC implementation is correct.

A good PLL or whatever (ie Ultralock, Crystallock, übersynch...) the DAC manufacturer uses to lock the input signal to the DAC's own clock should annihilate the incoming jitter. After that, the internal jitter of the DAC is what matters.

So, with a proper DAC, source should make no difference provided the signal is stable enough to prevent a drop out.

So, does it mean that cheap DACs are not properly made? Maybe. But what about people who still hear a difference between transports with expensive DACs, surely the manufacturer would know how to make a proper implementation...

BUT, HYPOTHETICALLY SPEAKING, would they want to? Should they also sell a transport (most of them do), showing that their transport is audibly better than a cheap one contributes to their reputation and opens a the market for expansive transports. There would be no advantage for a hi-fi manufacturer to make a DAC with unaudible incoming jitter. So they make musical DACs that rely on the source to eliminate incoming jitter.
 
Feb 7, 2010 at 12:22 PM Post #20 of 177
Quote:

Originally Posted by estreeter /img/forum/go_quote.gif
What Hi-Fi put 3 music lovers in a room last year and played the same selections (mainly classical) through 3 separate rigs into the same DAC:

1. ipod+ND-S1 Onkyo transport
2. CDP
3. Computer hard disk

Without wanting to get bogged down in the specifics of the kit involved, all 3 rated the ipod-based rig as their least preferred, one opted for the CDP and the other two were most impressed with the computer transport. Probably a bit convenient when it supported WHFs earlier contention that the ND-S1 wasnt on a par with an entry-level CDP, but I was surprised by the extent to which each of the test subjects reported major differences between the 3 rigs. Same DAC, presumably the same cables etc.

The debate over jitter levels, RFI and DBT wont go away anytime soon, but i'd definitely like to be part of such a panel, preferably with music more in line with my own preferences.



A solution would be for far more publications/forums to organise such tests as the What Hifi 'Big Question'. Has anything been done at a Can Jam or other head-fi meets?
 
Feb 8, 2010 at 6:45 AM Post #21 of 177
So I modded the D2C today (power-supply cap replacement; shorted DC blocking caps; took out the balance output caps; got rid of the headphone amp; and finally, added a 8.5V EI core transformer for the digital power). Then I compared a few more transport/cables.

gear:
-Sony X555ES CDP
-Sony C601ES changer
-Sony CA70ES changer
-Sony blueRay player (the cheap $130 stuff)
-Thick and flexy optical cable (no marking, was supposedly made by BJC)
-Thin generica optical cable (Sharp brand, originally costed me $2.5)
-AudioQuest cinemaquest video/digital coax cable (6').

The Dac is, of course, the modded Zhaolu; Headphone amp is a Stax SRM1 with output cap upgrade, driving a pair of HeAudio Jade's.

Some results:
*with the thick optical cable:
X555ES has the softest sound, the C601ES has the sharpest. CA70ES is somewhere in between. The X555ES is way soft, can't be just placebo.

*Difference between thick and thin optical cable (using C601ES as transport):
the thick cable is mellower; the thin Sharp cable has more sparkles and a little more "metalic". Difference is not huge but noticiable with a quick A/B.

*Somehow "C601ES -->thick optical" combo sounds the same as "Blueray -->digital Coax".

So, the new question: why would optical cables sound different ?! They are just light pipes.....
 
Feb 8, 2010 at 10:39 AM Post #24 of 177
Quote:

Originally Posted by n3rdling /img/forum/go_quote.gif
They sound different because you're looking.


If you mean 'looking for differences', I think there is something to that. Tell me that you are going to be switching gear while I wear a blindfold and my brain is going to be looking for whatever differences it can discern : not sure if the 'pros' can avoid this, but that would be my approach. Its where reviewers struggle to find words to describe something less than a 'smidgen' ..

If you mean we hear differences because we can see the gear being tested, that doesnt explain how all 3 WHF reviewers preferred either CDP or hard disk over the iPod - same DAC. My single criticism was that leading with the iPod-based rig then moving to the other two made the first set of impressions the baseline, but I dont want to get into a DBT discussion as I know where it will go.
 
Feb 8, 2010 at 11:02 AM Post #25 of 177
Have you ever noticed how your equipment sounded like their physical appearance ie the

HD 600/650 sound mellow => dark coloured with round shapes
AKG K701 sounds transparent and bass light => white headphone with high tech aspect and rather thin headband.
Denon Dx000 spind lush with a lot of bass => luxurious looking headphones
Grado sound fun and engaging => vintage look with wooden cups...

So, do we really hear with our eyes? OR maybe it's the constructors adapting the look to the sound
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Feb 8, 2010 at 12:59 PM Post #26 of 177
Quote:

Originally Posted by khaos974 /img/forum/go_quote.gif
So, do we really hear with our eyes?


Yes we do. How we hear things is almost fully based on what our expectations are. Literally everything affects how we perceive the sound of audio equipment. Prices, looks, current mood, the room we are in, the seat you are sitting, everything. It's not a small difference either.

I think this has been discussed on Sound science numerous times.
 
Feb 8, 2010 at 7:39 PM Post #27 of 177
Quote:

Originally Posted by IPodPJ /img/forum/go_quote.gif
Optical cables should sound no different at all. As another poster mentioned and I can verify this, you can get an audio signal without pushing the cable all the way into the plug. I used to use a 200 strand glass cable when I messed around with optical.



I wiggled the optic connetor and pushed it in and out a little, the sound didn't change....I have read the alignment is not super critical per the Toslink spec.
 
Feb 8, 2010 at 7:42 PM Post #28 of 177
Quote:

Originally Posted by n3rdling /img/forum/go_quote.gif
They sound different because you're looking.


I was actually expecting the C601ES/Toslink to sound different from Blueray/Coax, but they sound the same. Basically no difference.

Meanwhile, I thought the X555ES should give a sharper sound (its analog out has higher resolution than the others) but it was actually more mellow as a transport......

redface.gif
 
Feb 8, 2010 at 7:43 PM Post #29 of 177
Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif
I wiggled the optic connetor and pushed it in and out a little, the sound didn't change....I have read the alignment is not super critical per the Toslink spec.


^ +1

I played with the optical cable and the optical input on my DAC, even when I didn't plug the cable into the DAC, I was able to get good sound.
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