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Transport - does it matter to the sound at all?

I wanted to start this thread, to gain some insight into peoples experiences on this subject.
My view: From the outset of CD and digital media, we were force fed the view that 'its digital so always sounds the same whatever' ideology. Remember the jam on the cd, and it doesn't skip. Since these naive beginning we quickly found out it did matter, and the quality of components, interconnects (its wire isn't it so doesn't affect the sound?) and design DID affect the sound. So I firmly believe that a transport does affect the signal quality and final sound output in a big way. There are transformers, capacitors, boards, wires, all the components that have such a bearing on quality output on all the other components in a system. And the motor, the bearings, the transport mechanism, jitter correction, noise, damping, vibration from itself and speaker interaction ALL will affect the sound.

My question, what are the views on this balance between cost on a DAC and the transport. Are many of us getting it wrong bolting on Sony DVD players to high quality DACs? And are many of the 'quality transports" out there just re-boxed philips units. It does appear very few manufactures build their own transports aka Meridain, Linn and Naim to mention a few.

It would be great to see a high quality transport kit out there, which would allow a full transport and kit DIY project, with mods and part upgrades available at an affordable price.

I haven't the money at present to upgrade my DAC, which is an upgraded Audio Note DAC 1.1 and Zero transport, but I am very happy it at the moment as it was a huge jump over oversampling units I had owned previously.
astrostar59
jsadurni
210 posts
 
I dont know about ESP, but my jitterous transport is scary!!!

Maybe Saendtaylor99 is on to it with the input signal:
this is from the Attraction DAC: "The high integration of unique features was achieved by the development of a special digital receiver-chip (Altmann R16)."

"The digital input signals are recovered with extremely low jitter as they are generated by custom made voltage-controlled crystal-oscillators (VCXOs) and employ the UPCI (Ultra Precision Clock Injection) technology."

"A switchable JISCO-function (Jitter Scrambling Decorrelator) further increases sound quality as jitter-components from the DVD-A or CD player are decorrelated before being ultra-precision-filtered."

"
http://www.mother-of-tone.com/attraction.htm

very interesting reading...

I havent heard the DAC but it has rave reviews, and its really nothing fancy, a nonos DAC and an opamp...yes battery power supply.

Steve do you know which other dacs use this technology?

Best,
seandtaylor99
1,262 posts
 
Jsadurni, I certainly don't claim to know the answers to this problem, but here is another DAC manufacturer who says that all transports sound the same, provided they are slaved to an accurate clock in the DAC

http://www.lessloss.com/about.html

And another paper by Dan Lavry, maker of pro-audio DACS (that are very highly regarded)

http://www.lavryengineering.com/white_papers/jitter.pdf

It certainly seems to me that the answer to jitter lies in a properly designed DAC, not in the transport, but I'm always open minded, and if anyone would care to step in with a technical explanation why this is not the case I'd be very pleased for them to do so.
audioengr
3,282 posts
 
Jsadurni - I have a couple of Off-Ramp customers that are using the Altmann DAC. They seem to like it. I dont really understand what this JISCO thing is. I have reports from some that it is better turned-off. Others seem to like it on. Looking at the parts and board design I'm not impressed and evidently some digital signals pass through a toggle-switch? It may sound good though. Never heard one. The battery power definitely helps.

The only DAC that I'm aware of that uses a true jitter rejection technology is the Lavry. This is sound technical design. Interesting feedback from a customer that upgraded from a Audiophile USB to an Off-Ramp Turbo 2 though. It sounded better, more focused. Maybe it does not reject all jitter? Still one of the better designs available commercially.

Steve N.
audioengr
3,282 posts
 
Seandtaylor99 - I would not put the onus on either the DAC or the Transport. Either can have very low jitter. However, the closer you get to the D/A chip with a low-jitter clock, the better the result. The problem is that most modern DAC chips dont use the classical "word-clock" to actually do the conversion. They more often use the bit-clock or even the master clock, which are much higher frequency. This is why I prefer the I2S interface. It enables all of the clocks (SCLK, MCLK and L/RCLK) to be close to the D/A chip. If the source of these clocks is low-jitter, then mission accomplished. This is what I do in my Pace-Car.

Steve N.
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