SPDIF OUTPUT

[kawo]

Would like to ask, CD / DVD ... the SPDIF digital output of the wave has impact on the DAC to it?

[ARTISAND]

YES IT HAS. THE CORRECT TIMING IS THE MOST INPORTANT REASON FOR GOOD SOUND.IT"S NAME IS JITTER,THE LESS IS PREFERABLE.THERE ARE CIRCUITS TO RECLOCK THE DATA FROM SPDF OUT TO VERY LOW VALUES,SAY 1-2PS.EXPENSIVE CD PLAYERS HAVE MUCH CARE IN THIS SECTION

[kawo]

Thank's

I see the cd player in this site's output to 20 ns.

http://www.acec13.fr/tvc/REMI/SPDIF_...f_measurements

If I like him SPDIF fixes the wave type, DAC will sound better?

[renaudagnes]

Please note the new adress of our SPDIF Hall of Shame :

TVC Audio-SPDIF Hall of fame

[kawo]

Thank you, it is this web site, do not know the extent of impact on the sound. I also intend to be similar to their own things.

[ARTISAND]

You will find on Ebay circuits which minimize jitter to extremely low values.Jims Audio sells one,it"s price is 71$, and it's name SPDFisolator.This circuit is placed between SPDFoutput and DAC,and is a ready made.All you want to do is the supply.

[kawo]

Thank you, but I'm not looking for them, my CD player to do by adding a clock timing, I would like to know if the wave type and modified SPDIF rise time reduction will help?

[renaudagnes]

Consider this : if you install a very accurate clock in your CD player, you will have a killer. That's the mod to do first !

For the SPDIF output, this is the second step, after the clock. Anyway, if your spdif input circuit in the DAC is a "high jitter" circuit, you lose a part of your efforts : you have to install a SPDIF INPUT in you DAC, bypassing the legacy input circuitry.

Another information : avoid the use of RCA connectors because they cannot handle the 75ohms. Because the RCA is the worst solution, you can here the difference beetwen cables. With the BNC you can select connector and cable that do the job, for instance BNC 75 Ohms from "Radiall" and cable type RG179 from Nexans

The cable and the connectors are 75 ohms. You have to not use the soldering iron by the tool to press the connector on the cable, in other case the difference of material produces a brake of the 75 ohms.

The cost of this kind of cable is something like 40€, the passband is higher than what we need for the signal and everything else is pure ********.

Here is a picture to explain what we have achieve with a very precise clock, spdif output, cable and spdif input from our conception (fs is for femto second and ps to pico second) :



With have installed our SPDIF input in a venerable Wadia 1000 (from 1990) to bypass the Sony circuit well know for it's very high jitter. The whole story is here (in french, but you can use google translation service).

[SoNic_real_one]

Originally Posted by renaudagnes

Consider this : if you install a very accurate clock in your CD player, you will have a killer. That's the mod to do first !

Consider this: The jitter in a transport is not "created" by the local clock! Jitter in a transport is direct result of the mecahical tracking of optical track, wobling of the disc itself, motor and clamp bearings wear, accuracy of the motor PLL loop and so on...

A "superclock" in a bad mechanical transport does nothing to solve the jitter. Is just "wishfull thinking" and people think that they hear a difference when is none to be heard...

[macboy]

Originally Posted by SoNic_real_one

Consider this: The jitter in a transport is not "created" by the local clock! Jitter in a transport is direct result of the mecahical tracking of optical track, wobling of the disc itself, motor and clamp bearings wear, accuracy of the motor PLL loop and so on...

A "superclock" in a bad mechanical transport does nothing to solve the jitter. Is just "wishfull thinking" and people think that they hear a difference when is none to be heard...

You are wrong. Data coming off the disc is buffered and clocked back out of that buffer to make it's way eventually to the DACs. Only the clock at the output side of that buffer can possibly make any difference. Jitter from the opto/machanical system can never, simply never influence jitter in the digital audio stream.