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General HIFI => Transports => Topic started by: 3bm on September 11, 2010, 10:53:51 PM

Title: The role of a transport
Post by: 3bm on September 11, 2010, 10:53:51 PM
placeholder for a stick on the role of a transport in your audio system. any information please add.
Title: Re: The role of a transport
Post by: kajak12 on September 16, 2010, 07:51:58 PM
it is the start of the digital chain it will make or break the system.
Title: Re: The role of a transport
Post by: Drizt on September 16, 2010, 11:11:15 PM
As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples, then the transport 'should' have no impact on the sound quality.  I have read scientific studies that state that 250ms is the threshold of audibility with regards to jitter.  Considering something like a humble SB3 has a 3rd party confirmed jitter measurement of 80ps on the coax digital out would suggest that in most circumstances jitter is irrelevant.  I'm happy to read any rebuttals to this that have some scientific research behind it like blind testing results etc.  Anyone have any ?
Title: Re: The role of a transport
Post by: 3bm on September 16, 2010, 11:19:44 PM
Hi mate. should have one in melbourne soon so if you wanted to check it out let me know.
Title: Re: The role of a transport
Post by: kajak12 on September 16, 2010, 11:24:24 PM
As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples, then the transport 'should' have no impact on the sound quality.  I have read scientific studies that state that 250ms is the threshold of audibility with regards to jitter.  Considering something like a humble SB3 has a 3rd party confirmed jitter measurement of 80ps on the coax digital out would suggest that in most circumstances jitter is irrelevant.  I'm happy to read any rebuttals to this that have some scientific research behind it like blind testing results etc.  Anyone have any ?
no blind tests just sighted tests and a lot of them from a lot of members here and other forums
Title: Re: The role of a transport
Post by: Drizt on September 16, 2010, 11:58:41 PM
As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples, then the transport 'should' have no impact on the sound quality.  I have read scientific studies that state that 250ms is the threshold of audibility with regards to jitter.  Considering something like a humble SB3 has a 3rd party confirmed jitter measurement of 80ps on the coax digital out would suggest that in most circumstances jitter is irrelevant.  I'm happy to read any rebuttals to this that have some scientific research behind it like blind testing results etc.  Anyone have any ?
no blind tests just sighted tests and a lot of them from a lot of members here and other forums

Fair enough if thats enough for you.  No arguments from me.
Title: Re: The role of a transport
Post by: ozmillsy on September 17, 2010, 07:26:54 AM
As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples, then the transport 'should' have no impact on the sound quality. 

If you can hear an audible difference, then there is no other explanation for that difference,  other than jitter in the stream is degrading the performance of the dac.   If someone claims that a certain "threshold" isnt audible, then it is a subjective assessment in my opinion.   

Like the claim that we cant hear frequencies over 20k.  It's widely accepted now, that brickwalling audio at 20k makes an audible difference, whether you can hear a 25k test tone is irrelevant.

I'm happy to be blind tested on transports I am familiar with, any time.
Title: Re: The role of a transport
Post by: Drizt on September 17, 2010, 07:46:45 AM
Cool.  If you do one I'll be interested in reading your results.
Title: Re: The role of a transport
Post by: ozmillsy on September 17, 2010, 07:48:55 AM
Cool.  If you do one I'll be interested in reading your results.
As soon as someone comes over to facilitate, no problems.   But, I'm not running out and organising a GTG just to do it, as I have no reason to. I trust my ears.

My missus is not interested, and not willing to change cables on the system.
Title: Re: The role of a transport
Post by: tuyen on September 17, 2010, 09:34:13 AM
I would be happy to sit the double blind test if someone in Perth is willing to organise and host it.

After owning a SB Transporter, modded CD94 and listening to a SB Duet,   I would even be willing put money on the table! :)

Only condition is that the test has to be conducted on a certified 'killer' system (as not all hifi systems out there are able to show differences between transports).

Title: Re: The role of a transport
Post by: Drizt on September 17, 2010, 02:55:53 PM
Do it :)  Would love to read about the methodology used, the number of test subjects, number of iterations etc.

Also it would be good to take a screen shot of the relevant Squeezecentre settings (e.g. replay gain is disabled, digital volume control is disabled etc.)  Basically making sure that the signal is not messed with before hitting the DAC.



I would be happy to sit the double blind test if someone in Perth is willing to organise and host it.

After owning a SB Transporter, modded CD94 and listening to a SB Duet,   I would even be willing put money on the table! :)

Only condition is that the test has to be conducted on a certified 'killer' system (as not all hifi systems out there are able to show differences between transports).


Title: Re: The role of a transport
Post by: kajak12 on September 17, 2010, 07:01:02 PM
transports can take you into another world with music being played or make you get up and turn your system off.
Title: Re: The role of a transport
Post by: ozmillsy on September 17, 2010, 09:35:59 PM
transports can take you into another world with music being played or make you get up and turn your system off.

Unless you dont know any better?
Title: Re: The role of a transport
Post by: Upfront on September 21, 2010, 09:18:44 PM
That would be me! My VRDS10 Teac arrives on Friday! I'm a bit excited! It has the power supply upgraded and a tricord clock. Don't shoot me!!! Will know more when I take the lid off on Saturday.
Title: Re: The role of a transport
Post by: kajak12 on September 21, 2010, 09:21:01 PM
That would be me! My VRDS10 Teac arrives on Friday! I'm a bit excited! It has the power supply upgraded and a tricord clock. Don't shoot me!!! Will know more when I take the lid off on Saturday.
you got to bring this over for a test run against the cd94 very curious
Title: Re: The role of a transport
Post by: Upfront on September 21, 2010, 09:23:38 PM
Will do mate. Will post some photos for you to have a look first.
Title: Re: The role of a transport
Post by: kajak12 on September 21, 2010, 09:25:22 PM
Will do mate. Will post some photos for you to have a look first.

yes eye candy is a good start
Title: Re: The role of a transport
Post by: mikey d on September 28, 2010, 08:50:56 PM
Having 3 kids at uni & building my own house, funds are just not there to swap & change set ups as often as my whim would take. Has taken a while to get to the place that I'm at now. Loving my music as much as anyone else here, I get great enjoyment out of my modest system. Have been running a Rega Saturn for a couple of years & feel that it makes pretty nice music. Am aware of the fact that it can be bettered by many other cdps & transport/ DAC combos BUT one day I know I will be able to give you all my impression of my very own killerDAC. I have had one very brief phone convo with Steven & my very astute sense of intuition tells me that he is a very honest, sweet & humble man & the sort of bloke that I would like to do business with. I want to hear the wonderful music that his genius can give. Question......will the Saturn suffice for a period as the transport????? How much goodness will I be missing without a Marantz feeding it?????
Title: Re: The role of a transport
Post by: crazikid on September 28, 2010, 09:03:39 PM
mikey d... where are you located.. if you could try yr saturn with a KdAc would show if the combo works... gee.. even plane flights are cheap.. get on a plane and audition the combo for yourself
The KDac changed my life... it might change yours :o
Title: Re: The role of a transport
Post by: kajak12 on September 28, 2010, 09:05:21 PM
Having 3 kids at uni & building my own house, funds are just not there to swap & change set ups as often as my whim would take. Has taken a while to get to the place that I'm at now. Loving my music as much as anyone else here, I get great enjoyment out of my modest system. Have been running a Rega Saturn for a couple of years & feel that it makes pretty nice music. Am aware of the fact that it can be bettered by many other cdps & transport/ DAC combos BUT one day I know I will be able to give you all my impression of my very own killerDAC. I have had one very brief phone convo with Steven & my very astute sense of intuition tells me that he is a very honest, sweet & humble man & the sort of bloke that I would like to do business with. I want to hear the wonderful music that his genius can give. Question......will the Saturn suffice for a period as the transport????? How much goodness will I be missing without a Marantz feeding it?????
i know the saturn well as i used jlti modded players against a saturn a few years back.the truth is the jlti modded players where better then the saturn.the marantz cd94 is just on another planet.
diffrence between marantz and saturn is analogue vs digital
take your saturn to steves house and compare lets your ears be the judge.
Title: Re: The role of a transport
Post by: mikey d on September 28, 2010, 09:21:06 PM
diffrence between marantz and saturn is analogue vs digital

mario, are you speaking in technical terms or listening impression?
Title: Re: The role of a transport
Post by: crazikid on September 28, 2010, 09:25:10 PM
dont listen to mario... try for yourself... its all subjective!
Title: Re: The role of a transport
Post by: mikey d on September 28, 2010, 09:33:46 PM
I am interested in Mario's opinions as well anybody else with more experience than myself. We all have different ears, brains & musical preferences so I will only do what appeals to me. I should go visit Steve one day with a few bits of my gear & see how things sound. I'm mid way 'tween Sydney n Brisso in the bush, beautiful lifestyle but audio wasteland
Title: Re: The role of a transport
Post by: crazikid on September 28, 2010, 09:40:12 PM
rev the car and head to the blue mts.. i'm headin there this w/e from brisbane...
Title: Re: The role of a transport
Post by: mikey d on September 28, 2010, 09:46:44 PM
Hey Crazi, I'm 25kms west of Kempsey.....almost tempted to hitch a ride but have tickets to the Bellingen Global carnival. Great live music is pretty uncommon around here too (but it is the home of Slim Dusty....lol). Let me know what sweetness you indulge in with Steve.
Title: Re: The role of a transport
Post by: kajak12 on September 28, 2010, 09:55:11 PM
diffrence between marantz and saturn is analogue vs digital

mario, are you speaking in technical terms or listening impression?
use your own ears.
saturn is grainy edged as a transport compared to marantz listening impression
Title: Re: The role of a transport
Post by: mikey d on September 28, 2010, 09:59:16 PM
I guess heading to Steven's with cdp & speakers & a bottle of red (or 3) would be illuminating.
Title: Re: The role of a transport
Post by: kajak12 on September 28, 2010, 10:08:41 PM
I guess heading to Steven's with cdp & speakers & a bottle of red (or 3) would be illuminating.
that trip will change your life forever ;D
Title: Re: The role of a transport
Post by: crazikid on September 28, 2010, 10:12:06 PM
It change my life. I had to get new speakers and amps.
Title: Re: The role of a transport
Post by: mikey d on September 28, 2010, 10:28:06 PM
After a family holiday to Nepal in December I'll have to get on down to the Blue Mountains. If I canceled the holiday that would pay for a whole new killer system but then my family would disown me.....what to do? What to do?????mmmmm
Title: Re: The role of a transport
Post by: ozmillsy on September 28, 2010, 10:29:47 PM
the killer can transport you anywhere,  just turn the lights off and let the music take you there.   :D
Title: Re: The role of a transport
Post by: kajak12 on September 28, 2010, 10:30:33 PM
After a family holiday to Nepal in December I'll have to get on down to the Blue Mountains. If I canceled the holiday that would pay for a whole new killer system but then my family would disown me.....what to do? What to do?????mmmmm
my wife and kids disowned me allready all i do is forum,soldering,ordering parts and listening
Title: Re: The role of a transport
Post by: mikey d on September 28, 2010, 10:32:20 PM
You guys sure have a killer instinct!
Title: Re: The role of a transport
Post by: Jehuty on September 28, 2010, 10:37:02 PM
You can go for holiday anytime, but the killerDAC is not anything like commercial offer, as Steven says he's very lucky if he can build 1 every month.
Title: Re: The role of a transport
Post by: crazikid on September 29, 2010, 08:41:25 AM
The Waiting list for the KDAC must be growing....
Title: Re: The role of a transport
Post by: tuyen on September 29, 2010, 09:29:05 AM
LOL!  Good health and safety for family always come first!  For me anyway :)

In saying that, I will make sure my killerDAC is one of the items I have with me to the grave!
Title: Re: The role of a transport
Post by: mikey d on September 29, 2010, 10:08:57 AM
That's the right perspective on life Tuyen.......even better if the family loves your stereo!
Title: Re: The role of a transport
Post by: PET-240 on December 11, 2010, 10:12:57 PM
May I ask if anyone has done any of the mods here http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/FIKUS/Fikustransport.html (http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/FIKUS/Fikustransport.html)

Seems a little unconventional, esp the SPDIF output mod with a tube!!!!

Worth reading though, seems he has his head on regarding what he hears..........

Still looking forward to the modding sessions on the CD94.......and everything else.....
Title: Re: The role of a transport
Post by: kajak12 on December 12, 2010, 01:29:01 PM
May I ask if anyone has done any of the mods here http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/FIKUS/Fikustransport.html (http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/FIKUS/Fikustransport.html)

Seems a little unconventional, esp the SPDIF output mod with a tube!!!!

Worth reading though, seems he has his head on regarding what he hears..........

Still looking forward to the modding sessions on the CD94.......and everything else.....
i thought about it many times due to i2s being used it never happened
Title: Re: The role of a transport
Post by: Naughtius_Maximus on January 14, 2011, 12:25:30 AM
As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples, then the transport 'should' have no impact on the sound quality.  I have read scientific studies that state that 250ms is the threshold of audibility with regards to jitter.

You do realize that 250ms is ONE QUARTER OF A SECOND don't you. If your source was set up to pause for 250ms every second and you can't hear it, you must be pretty deaf.
Title: Re: The role of a transport
Post by: Drizt on January 14, 2011, 08:37:52 AM
As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples, then the transport 'should' have no impact on the sound quality.  I have read scientific studies that state that 250ms is the threshold of audibility with regards to jitter.

You do realize that 250ms is ONE QUARTER OF A SECOND don't you. If your source was set up to pause for 250ms every second and you can't hear it, you must be pretty deaf.

Lol at the typo . 250ns
Title: Re: The role of a transport
Post by: davewantsmoore on February 20, 2011, 12:42:21 PM
As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples.

If you are attempting to assert that the above statement is the null-hypothesis when evaluating at digital transports..... Then you are absolutely right, congratulations !!!

..... However, I believe you totally underestimate the enormity of the task you have identified.



Consider SPDIF.   The waveform of SPDIF has a bandwidth of 30 MHz

Unless your transport is approaching perfect, then SPDIF waves on a scope are nothing like square .... This introduces jitter/distortion in the receiver and DAC chip.


It's all very well to run some type of "bit perfect" test, using many available methods .... and decide that "bits in = bits out" and everything is dandy  .....   but these tests are only tell you the output data is the same as the source data while it's sitting still  .... it says nothing about the time domain.

It is this difference in the time domain, that introduces the distortion in the analog output of a DAC.


As to whether this distortion is audible, it's going to be very system dependant, as it can easily be masked by other things in the playback system.



In short:   The laws of physics are very clear that any less than perfect timing of bits will make distortion.  There are very clear oscilloscope measurements (google) showing even the most perfect transports in existence not being 100% perfect square waves.


So rather than trying to arrange blind testing to prove the laws of physics wrong ... why don't you stick to a much simpler question   "is it audible in playback system X?"
Title: Re: The role of a transport
Post by: Erik van Voorst on May 13, 2011, 03:25:22 AM
I think a transport is incredibly underestimated...based on "all it has to do ..blah blah blah"

First I came to that conclusion buying commercial transports in order to upgrade (leaving the dac alone)

Those were major upgrades to my ears...first the philips 850 (iirc) then the marantz 83 (iirc)
then a accuphase 63 (iirc) and finally a Wadia 23...

To take the experience further...during the building of a transport I heard major chances implementing different components...

Believe it or not maybe I find a good transport even more important then a top-of-the-bill dac
(oops wrong forum  ;D)...
Title: Re: The role of a transport
Post by: kajak12 on May 13, 2011, 11:00:01 AM

Believe it or not maybe I find a good transport even more important then a top-of-the-bill dac
(oops wrong forum  ;D)...
what came first a chicken (transport) or the egg (dac)
Title: Re: The role of a transport
Post by: Erik van Voorst on May 13, 2011, 05:44:29 PM
How true  ;D

I guess in the end each and every component is of the same importance, since implementing a single new component is able to dramatically change your sound.

Last week we introduced new 3  pre-amps (Lua-Jadis-Aitos) at a friend in his set so he could decide which one to buy....the effect was stunning... :o
Title: Re: The role of a transport
Post by: zjaakco on October 05, 2012, 12:00:27 AM
Hi all
Hi erik,
 
I have the same opinion as you about a transport.
Its more importend tham a dac, because its the source of reproduction.

regards
Title: Re: The role of a transport
Post by: Erik van Voorst on February 11, 2013, 06:28:51 AM
Hi guys

Again I cannot even begin trying to emphasize the importance of a good transport...
I wonder who bought the boombox JVC and made a start....it is bye bye Wadia Mark Levinson Cec Accuphase and pretty much all the commercial ones...

At the moment I am busy building one for my friend and EVERY modification is from noticable to jaw dropping.

But do not take my word for it...buy one yourself and make a start..

In America they have on the DIY the shigaclone...that will give you a flying start...but please take it further than Peter Daniel does...it is worth it....besides when you have a killer dac you need a killer transport  8)
Title: Re: The role of a transport
Post by: kajak12 on February 13, 2013, 12:46:26 AM
Hi guys

Again I cannot even begin trying to emphasize the importance of a good transport...
I wonder who bought the boombox JVC and made a start....it is bye bye Wadia Mark Levinson Cec Accuphase and pretty much all the commercial ones...

At the moment I am busy building one for my friend and EVERY modification is from noticable to jaw dropping.

But do not take my word for it...buy one yourself and make a start..

In America they have on the DIY the shigaclone...that will give you a flying start...but please take it further than Peter Daniel does...it is worth it....besides when you have a killer dac you need a killer transport  8)
but i have a killer transport its a marantz cd94 with zen clock
Title: Re: The role of a transport
Post by: Erik van Voorst on February 15, 2013, 05:03:21 AM
Hahahaha...prize yourself lucky then.....so you know first hand what a shocker it is when visitors bring another transport into your setup......even the expensive names.....   8)

I really do believe that a cdplayer (transport and dac) are together the most important component in order to enjoy music....and of those two the transport upfront.

Do not ask me that next year....when my pre amp is "taken care off"  :P 8)
Title: Re: The role of a transport
Post by: rhlauranna on February 16, 2013, 03:29:54 AM
Hahahaha...prize yourself lucky then.....so you know first hand what a shocker it is when visitors bring another transport into your setup......even the expensive names.....   8)

I really do believe that a cdplayer (transport and dac) are together the most important component in order to enjoy music....and of those two the transport upfront.

Do not ask me that next year....when my pre amp is "taken care off"  :P 8)

Hi Erik,

nice to read you again...

well, let me add: you should listen to PC harddrive SSD via DAC, this is simply a quantum leap above traditional CDplayer transport...

if you would like to, just tell me...

Title: Re: The role of a transport
Post by: Erik van Voorst on February 16, 2013, 04:31:16 AM
No because if you are right (and you probably are) you take away a lot of fun for me including 3000 compactdiscs  ;D
Title: Re: The role of a transport
Post by: kajak12 on February 17, 2013, 09:22:22 PM
Hahahaha...prize yourself lucky then.....so you know first hand what a shocker it is when visitors bring another transport into your setup......even the expensive names.....   8)

I really do believe that a cdplayer (transport and dac) are together the most important component in order to enjoy music....and of those two the transport upfront.

Do not ask me that next year....when my pre amp is "taken care off"  :P 8)

Hi Erik,

nice to read you again...

well, let me add: you should listen to PC harddrive SSD via DAC, this is simply a quantum leap above traditional CDplayer transport...

if you would like to, just tell me...


funny you say that but so far its not the case for some of us...............