Any project with PCM1704

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My PCM1704 DAC

PCM1704 x 4
Only for CD transport :)
 

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thank you for sharing details about your pcm1704 converter
you changed stacked ad844 + opa627 to opa861 + opa861, and shunt regs to serial regs with LT3045
any experience with discrete buffer (Joachim Gerhard / EUVL jfet buffer, SparcosLabs, diamond buffer) Instead of opa861
did you experience offcet from opa861

...well said jesper
I would like to draw attention to my personal interpretation of the most appropriate use of the PCM1704 chipDAC. My work has developed using just the JLSounds I2sOverusb USB card that is able to process the i2s signal in the language accepted since 1704 without needing any logical glue (useless with JLSounds). Not to mention the whole process refer to the description made for friends in my Italian forum.

In the mature form of my construction there is a motherboard that connects two mono miniboards that welcome the pcm1704 with the jlsounds. moreover, the IV card based on the OPA861 is used, both for conversion and as a buffer (circuit taken entirely from the P.Rogic project for the AYA DAC). All power supply(six) are currently based on the LT3045 (Ivanov boards).....previously salas shunt.....and previously others shunt

How does it sound? Really very good both for me and for many friends who wanted to replicate it.

PS..... my nick in italian forum is bigtube
 
My experience has been quite elaborate, but I have come to conclusions that are clear to me. The sense of using the 844 stack is to show the chipdac the lowest possible impedance. In this sense, the 861 reaches the goal better and with simplicity (this was the consideration that pushed Rogic in his AYA dac to prefer it to 844 in the evolutionary phase .... but not the only one). This, but not only this, affects the overall quality of the 861 conversion performance.
The buffer:
Both with the 844 (also in triple stack) and with the 861
I experimented with opamps all of high level: 627, 1641, 827.
With these I got excellent performance and the best was 827. to better evaluate, I then used two discrete circuits: the DCB1 and a diamond a bjt configuration. I preferred the latter in conclusion.
Stimulated by the enthusiasm shown by Rogic and also by other users, I finally tried the 861 in buffer mode. It was a beautiful discovery and became the final choice after repeated plays and comparisons. The only problem if we want is that the offset is present even if very limited. It can be eliminated by setting up a small circuit to balance and reset it. In reality, I did not and I had no problem. if necessary, a good output capacitor can be used.
 

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Hi,

I have 4 PCM1704U-J and JLSound I2SoverUSB board.
I2SoverUSB - I2S over USB Audio

My plan is make a reference DAC which Non-Oversampling, full balanced , XLR and SE two type outputs.

First this circuit base from pavouk.org then returned to balanced type.Can it useable with this way, what is your opinion about circuit? According to this circuit could you recommend a reference I/V Converter, LP filter output? It could be discrete design maybe a transformer. Or these OPA627 and OPA2134P output acceptable for a reference grade?

Also i'm not sure how can i convert XLR outputs to SE outputs, what is best methods for that?
 

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@alchamist:

I have 4 PCM1704U-J and JLSound I2SoverUSB board.
I2SoverUSB - I2S over USB Audio

Hi ... it's a bit difficult to see your schematic so this comment may/may not be relevant but just in case you don't know this:

I think that if you have the JLSounds board you don't need the right/left data alignment circuitry that is part of Pavouk's design. To my knowledge JLSound's board can be set up to work directly with e.g. PCM1704s. Maybe this is also what you have done in your schematic but I can't see it clearly ...

Also, I would consider a different I/V design than the one shown in Pavouk's design. There are different threads here on Diyaudio dealing with I/V design - two of those are:

dac I/V convertion with very low distortion

Zen -> Cen -> Sen, evolution of a minimalistic IV Converter

Hope this may be of inspiration & good luck with your endeavor ;-)

Jesper
 
I'm downloading it again but you must double click on arrows i guess.If you can see, hope we can talk again.

Hard to find genuine SK170 but diyaudio store sell it i didn't know that.SEN IV can be useful for me to make a ref IV stage.Is there any requirement to add LP filter, buffer or SEN IV be within all of them?
 

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Hi,

I have 4 PCM1704U-J and JLSound I2SoverUSB board.
I2SoverUSB - I2S over USB Audio

My plan is make a reference DAC which Non-Oversampling, full balanced , XLR and SE two type outputs.

First this circuit base from pavouk.org then returned to balanced type.Can it useable with this way, what is your opinion about circuit? According to this circuit could you recommend a reference I/V Converter, LP filter output? It could be discrete design maybe a transformer. Or these OPA627 and OPA2134P output acceptable for a reference grade?

Also i'm not sure how can i convert XLR outputs to SE outputs, what is best methods for that?

If you've got the JLSound USB->I2S you dont need pavouk's circuit...

For balanced operation, why not try Nelson's D1 ?

For SE output, use Hot pin & GND ? ... or put a switch on invert pin of the -DAC and tie both outputs together ?

For pure SE with 2 DAC's/ch there's some info in the attached Japanese AppNote.

'Reference design' from BB is OPA627 & OPA2134 + full OS 768khz...
Probably not what you meen by reference though...
 

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If you've got the JLSound USB->I2S you dont need pavouk's circuit...

For balanced operation, why not try Nelson's D1 ?

For SE output, use Hot pin & GND ? ... or put a switch on invert pin of the -DAC and tie both outputs together ?

For pure SE with 2 DAC's/ch there's some info in the attached Japanese AppNote.

'Reference design' from BB is OPA627 & OPA2134 + full OS 768khz...
Probably not what you meen by reference though...

Ref. design mean high end design and circuits which most popular not BB datasheet.

This app note great!Thank you.But it is little complicated for me.I'm searching for circuits. I will consider D1 and i found this circuit;

http://phil.charlet.free.fr/dac/d1.html

My questions are ;

I think C11 and C12 film capacitors will be better choice than electrolytic caps but capacitance too high for film capacitors and it seems costly,isn't it?

Is there no need to add a LP filter after D1 or can output directly goes to power amplifier/preamplifier? This question same for the SEN IV circuit?

Am i need to add a DC servo?

If i don't neet this circuit what type circuit you can recommend to me to use 4 PCM1704 with JLSound USB->I2S?

Best Regards
 
There is quite a few projects with the D1 around this forum, even a few with D1+PCM1704.

It will take some clever search though...

I haven't built it, I'm one chip short...but it is an elegant solution, as most Pass products :)

...If i don't neet this circuit what type circuit you can recommend to me to use 4 PCM1704 with JLSound USB->I2S?...

The JLSound board will output I2S in the correct format directly (if so configured) so no need for further logic, unless you intend to buffer or reclock...

So basically you connect the input of 2 PCM1704 in parallell for each channel with the invert bit set on the negative one.

I'm no good at explaining things and I haven't even begun to build mine...

Look at the servicemanual for the Pioneer RS-A9 for a good example of dual PCM1704/channel. (and an interesting I/V...)

If you can't find it, PM me ;)
 
I am grateful that you really clarified me about inverting and JLSound DATA inputs issue.That was very nice help.Inverting balanced application also seems at poineer service manual.

So first i must look to configure data format of JLSound board for DataL and DataR out.Then i wont't need to 74HCT164N logic delay and buffer.

For I/V converter i found this georgehifi's post.Can be used directly output of dac chips ;
 

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