PCM1704 or newer chips?

[tritosine]

Meitner's stuff:
http://www.google.com/patents?printsec=abstract&zoom=4&id=F6AnAAAAEBAJ&output=html

http://www.positive-feedback.com/pfbackissues/0802/pappas.Meitner.rev.8n2.html

 

[nagaesan]

Low Pass Filtering Impulse = A/D data

Hi! I am Tetsuya, Planner of original ALPHA's joke mode.

Let's think about "Band Limitting Impulse" like A/D conversion Music.


This Impulse is "TEST CD's data"

The data of sampling points are 000000010000000....

 

[nagaesan]

Low Pass Filtering Impulse = A/D data

And this is "Low Pass Filtering Impulse".

Please attention, these sampling points.

After filtering, you can see these sampling points are moved.
It is not 00000000100000000.

 

[nagaesan]

Probability

This is also band limitting impulse, but how much probability will be in nature world?

 

[nagaesan]

DA-S1 is this.

These D/A converters are my DENON DA-S1.

One DA-S1 is setting non ALPHA mode, and another DA-S1 is setting ALPHA mode.

If you have DENON CD Player that have original ALPHA processor, you can easy to set Non ALPHA or ALPHA by front pannel button.

 

[nagaesan]

WADIA's one stage 16fs DF and DF1706's 3 stage cascading 8fs DF

if initial filtering is done "slow -roll off" way, and the 96khz results is oversampled inside df1706 , thats a good way to minimise the integrated DF's impact on sound q.


Are there know the slow rolloff purporse and effect of 3 stage cascading over sampling FIR filter?


I think WADIA's one stage 16fs DF is nice idea.
Because this system, there is not word length rounding off between the step like DF1706, 3 stage cascading type oversampling Digital Filter, that 2fs-->4fs--->8fs.

But WADIA's DF, there is a weak point, that response of pass band is not flat, and stopband attenuation spec is not good for low order TAP FIR filtering.

 

[nagaesan]

WADIA's great point

And I think WADIA's nice point is 64fs over sampling.
They are using time delayed (moving averageing filter) 4 multibit DACs, 16fs FIR --->64fs.
There is no analog LPF device in WADIA DAC unit.

If we make 64fs over sampling DAC unit with Delta Sigma type DAC-IC, we must have analog LPF circuit. So WADIA choice multibit DAC-IC like AD1856 or PCM1704.

For such a reason, I think PCM1704 DAC is good choice.
I would like to make "No Analog Device LPF DAC unit" with one stage sharp rolloff LONG TAP interpolation FIR filter.

 

[EUVL]

Nagae-san,

So what do you think of this ?

http://www.diyaudio.com/forums/showthread.php?s=&threadid=140538

Then connect I2S to PMD100 or DF1704, followed by 4x PM1704 in balanced mode. No SPDIF, no PLL receiver. One clock for everything.




Patrick

 

[nagaesan]

That's very nice but why SD card?

>connect I2S
I think good choice.

>to PMD100 or DF1704,
Why choose f-max = 48kHz PMD100, f-max = 96kHz DF1704?

>followed by 4x PM1704 in balanced mode.
Good choice I think. My PCM1704 board is also 4x1704 balanced.
But my DAC is cancelling DC offset this balanced DAC.
How they cut DC offset? HPF? DC servo?

>No SPDIF, no PLL receiver. One clock for everything.
That's very nice. But compatibility is problem.

My DP-S1/DA-S1 also "384fs clock direct sync with ST-Link fiber cable, no PLL" But DP-S1/DA-S1 has selectable slock system.
1 is conventional S/PDIF AES/EBU DIR with +/-1000ppm rock in range LitaO3 VCO mode PLL,
2 is conventional DIR with +/-50ppm rock in range VCXO PLL and
3 is one clock crystal oscillator for CD decorder and Digital Filter DAC, by transmitting 16.9344MHz clock signal with ST-Link fibar cable.



And my question.

Why they choice small data strage device "SD" card?
Are not HDD good? Recently HDD price and go down, now very cheap and so big strage data. 1G Byte HDD is only 8000yen in JAPAN.


This is my 2G Byte HDD system with 4GB memory.
(This is just joke, it's a Windows PC but looks like high cost CD player )
http://www.teddigital.com/prod01.htm

 

[nagaesan]

Sorry 2G Byte ----> 2T Byte

This is my 2G Byte HDD system with 4GB memory.

This is my 2T Byte HDD system with 4GB memory.

 

[EUVL]

> Why choose f-max = 48kHz PMD100, f-max = 96kHz DF1704?

PMD100 is known to be a good filter, and I also have some HDCDs. Have not tried DF1704. Any experience ?

> How they cut DC offset? HPF? DC servo?

Not decided yet. Probably HPF passive.

> No SPDIF, no PLL receiver. One clock for everything.
> That's very nice. But compatibility is problem.

I only want to play Redbook CD. So 44.1kHz with 11.2896MHz clock. No problem using only SD card to play. DIY crazy solution .....

> Why they choice small data strage device "SD" card?
> Are not HDD good?

As a mechatronics engineer who also happens to know friends at Philips research, I do not like mechanical storage devices in my audio system. All solid state is the simplest and best solution. No reading errors, no mechanical noise, ...... Have been dreaming about this for years. But I am totally useless with uP stuff. So have to wait for someone else to provide the solution. From DAC onwards I can handle without problems.


Patrick

 

[nagaesan]

Measurement mechanical noise

Measurement my HDD transport ( Just PC )mechanical noise
http://www.teddigital.com/serv02.htm

attached file picture is FAN less power supply.

Measurement and recording of FAN noise
http://www.teddigital.com/serv01.htm


Is such an effort useless?

 

[nagaesan]

WADIA 170i

>I do not like mechanical storage devices in my audio system.
>All solid state is the simplest and best solution.

I would reccomend this WADIA 170i with digital output, than special SD card system . How about this?


http://www.bigpicturebigsound.com/Wadia_170iTransport_iPod_Dock_with_Digital_Output.shtml

 

[nagaesan]

Mecha-less system

This is mecha-less audio system with WADIA 170i and ESS ES9008S dac.
Black and silver chassis is my order made chassis, and inside chassis, there is ESS ES9008S eva-board.

 

[tritosine]

that wadia ipod gizmo had total jitter above 250 last time i read.

 

[nagaesan]

Non PLL DIR of ES9008S with WADIA170i

WADIA 170i has corexial RCA S/PDIF Digital output.
But this ES9008S DIR is non PLL timestamp decorder.
So I recomended, this DIR is very nice.

 

[tritosine]

yes, let's do synchronous reclocking ( digital lines or S&H) with multibit DAC , and we need no ESS number crunching (just send back a wordclock signal to source).

 

[tritosine]

http://www.audiofast.com/pdfs/effects.pdf

wow I just found this paper today!

We might see such ADC "A" type with PCM4222 "6bit multibit modulator out" + dsp, then transient response comes into play.


And a good transport:

http://audiogestalt.wordpress.com/

 

[inertial]

Re: DA-S1 is this.

These D/A converters are my DENON DA-S1.

HI Tetsuya ( hey you are young , not old!).
Wow ! I was near sure of that.....two pair DENON !!

One DA-S1 is setting non ALPHA mode, and another DA-S1 is setting ALPHA mode.[/B]

So you can hear easily "a difference ", no?
At the time, 15 years ago , a friend of mine had the Denons jewels.
I have listened at they 2-3 times but a lot of time is passed....
Please can you says what type of differences you can hear ?
And I am curious to see measurements in NON-ALPHA mode too.
I imagine frequency response do not change, impulse become ringing, etccetera. Am I right?

If you have DENON CD Player that have original ALPHA processor, you can easy to set Non ALPHA or ALPHA by front pannel button. [/B]

As I said my stupid friend has sold it !

But now, after your explanations, I am confused;
You speak of Joke, but I remember you have won various "awards" for your Alpha Processor.
All "Ignorants" in the Jury? :

One more . If I have well understood, your circuit is "incomplete" sort of, because during the A/D phase-process you do not have the "corresponding "-"specular" circuit.(?) Am I right or totally wrong?

Thus, apart beautiful pics for "morons audiophiles" ( ironic here), does Denon made a sort of "false"- technically and ideological ?
I am very worried by this aspect. Am I totally wrong?

Thanks
and Cheers,
Paolo ( disconsolate ex Denon-fan)

 

[Telstar]

Re: That's very nice but why SD card?

Then connect I2S to PMD100 or DF1704, followed by 4x PM1704 in balanced mode. No SPDIF, no PLL receiver. One clock for everything.


Patrick

I'd use pmd200 (there are a few chips available in china...).
Besides, it should produce a very good sound, for redbook only.

Why they choice small data strage device "SD" card?
Are not HDD good? Recently HDD price and go down, now very cheap and so big strage data. 1G Byte HDD is only 8000yen in JAPAN.

EUVL replied better than i could. Having no moving parts improves reliability, doesnt make any noise and SD cards can be used like CDs, i.e. having a physical support that could be stored in a (special) bookshelf.

Not my cup of tea, but very smart nonetheless.