The new Nonoz II DAC page !!!

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Guido Tent

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Joined 2001
TentLabs.com
Re: Asynchronous Reclocking

Elso Kwak said:



I have the digital and analog ground connected at the raw powersupply by a 2.2mH choke. The ground of the PLL section of the CS8412 is connected to the analog ground.
Using the low noise analog supply for the PLL of the DIR was one of the hints I got on AA.
The two diodes are straight from Kusunoki's paper. Jean-Paul did some "mailing". I have it too.:)
Click to expand...

Elso, others

Right layout for the grounds, well done (I even think you can do without the 2.2mH choke)

Question:

Since you are on the asynchronous path, why is the supply and hence jitter on the 8412 PLL important ?

best regards
 
Elso Kwak

Elso Kwak

Member
Joined 2001
geocities.com/elsokwak/
Re: Re: Asynchronous Reclocking

Guido Tent said:


Elso, others

Right layout for the grounds, well done (I even think you can do without the 2.2mH choke)

Question:

Since you are on the asynchronous path, why is the supply and hence jitter on the 8412 PLL important ?

best regards
Click to expand...

Hi Guido,
The choke idea emerged from the ferrite bead idea by Analog Devices. They placed the bead between the analog and digital groundplane on the DAC. When I did so with the AD1865 I got a lot of noise.

The Asynchronous Reclocker is not a complete cure for the disease called jitter. Even with Asynchronous Reclocking I hear differences in the transport, Wildmonkeysects loopfilter etc. etc.
I am now on the "one-box" route and still hear a improvement using Asynchronous Reclocking.
Best regards,
:cool:
 
Peter Daniel

Peter Daniel

Member
Joined 2002
audiosector.com
Paid Member
Re: Re: Re: Asynchronous Reclocking

Elso Kwak said:



I am now on the "one-box" route
Click to expand...

Looking at a circuit around TDA1543 it's really hard to understand the reason for separate DAC (unless for experimentation purposes, of course). The receiver circuit, with its separate supply, and input circuitry is more complicated than DAC alone and surely don't improve the sound. Just a single TDA1543 with 5 resistors, 2 caps and a simple PS wil improve most players, when using I2S connection, and it can be done in a half a day. It's cheaper that way too; no digital cables, no more problem sourcing CS8412, no gold plated BNCs;)
 
G

Guido Tent

Member
Joined 2001
TentLabs.com
Re: Re: Re: Asynchronous Reclocking

Elso Kwak said:


Hi Guido,
The choke idea emerged from the ferrite bead idea by Analog Devices. They placed the bead between the analog and digital groundplane on the DAC. When I did so with the AD1865 I got a lot of noise.

The Asynchronous Reclocker is not a complete cure for the disease called jitter. Even with Asynchronous Reclocking I hear differences in the transport, Wildmonkeysects loopfilter etc. etc.
I am now on the "one-box" route and still hear a improvement using Asynchronous Reclocking.
Best regards,
:cool:
Click to expand...

Hello Elso,

Like many other semiconductor manufacturers, also AD is not able to guide the user throughout decent board layout and design.

Ofcourse a choke between analog and digital ground is utter nonsense.

To all:

Any clue why you still hear effects of jitter in the front end when using asynchronuous reclocking ?

I think I have the answer but I am just curious .....

best regards
-
 
Elso Kwak

Elso Kwak

Member
Joined 2001
geocities.com/elsokwak/
Re: Re: Re: Re: Asynchronous Reclocking

Peter Daniel said:


Looking at a circuit around TDA1543 it's really hard to understand the reason for separate DAC (unless for experimentation purposes, of course). The receiver circuit, with its separate supply and input circuit is more complicated and for sure doesn't improve the sound. Just a single TDA1543 with 5 resistors, 2 caps and simple PS wil improve most players, when using I2S connection, and it can be done in a half a day. It's cheaper too that way; no digital cables, no more problem sourcing CS8412, no gold plated BNC;)
Click to expand...

Hi Peter,
Well I put "one-box" between quotationmarks as the analog circuitry and powersupply would be impossible to fit in my Philips CD-650.
It is a quasi one-box solution so to speak.
The discrete analog IV and outputbuffer PCB measures 15 x 20 cm (one channel), two PCB's on top of each other and two eurocards for powersupply filtering and regulation plus the two transformers.
Still thinking about putting the TDA1543 in the transport and bringing out the current outputs of the DAC to the other box. But you are right no more SPDIF problems, receiver supplies, resetcircuit, BNC's goldplated or not...Better sound too! ;)
I also have the opportunity to compare AB-ing with the selector swith of my preamp with TDA1541/ two dual opamps f.a. AD827 / no ASR. Quite funny:clown:
:)
 
Elso Kwak

Elso Kwak

Member
Joined 2001
geocities.com/elsokwak/
Re: Re: Re: Re: Re: Re: Asynchronous Reclocking

Peter Daniel said:
I noticed you still prefer active conversion to passive resistors. How it compares? I was always into simple solutions, so resistors appeal to me so far. I'm using 1k valueas. Any drawbacks if I go higher, like 2K, for more volume?



Funny in what way?;)
Click to expand...


Hi Peter,
The first minute I switch to the TDA1541 I hear no difference! A few minutes later I find the TDA1541 boring and I note the lack of bass slam.
Sorry not much experience with the simple passive IC-conversion.
Once I tried it with the AD1865 and noticed worse dynamics.
:bawling:
 
Elso Kwak

Elso Kwak

Member
Joined 2001
geocities.com/elsokwak/
AS431

jean-paul said:
TO92 is more convenient to use than DIL, they both can be equiped with a small heatsink. The SMD versions don't have this advantage. Please consider that there are many improved versions of TL431. Improvements include lower noise, higher precision, wider operating current and tighter temperature co-efficient.

Some of those improved versions are: TL431A, TL431B, AIC431, GS431 and AS431 to name a few. I have used the last one with good results.


.
Click to expand...

Hi Jean-Paul,
Where did you find this AS431?
I even couldn't find a datasheet...
:bawling:
 
HeadSh0T

HeadSh0T

Member
Joined 2002
i also just made a dac based on the Nonoz II design.. although I'm using TL431 throughout and I added a tube output stage.

I didn't use the 22R resistors between the CS8414 and the TDA1543. I just wired these pins direct. what are these resistors for and do I need them?

I will put the finishing touches on it and hopefully get some pics soon.

It sounds very good but I'm trying to decide if I should add some kind of active I/V conversion..
 
F

fedde

Member
Joined 2002
fedde.nu
"I didn't use the 22R resistors between the CS8414 and the TDA1543. I just wired these pins direct. what are these resistors for and do I need them?"

They make a sort of a LPF filter with the parasitic capacitance of the input pins of the DAC, filtering very high frequency information that can potentially increase the received jitter.

Fedde
 
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