dryman

Simple SPDIF-D/A-Converter needed
« on: September 07, 2012, 02:43:58 PM »
Hello,

i racked up an old NTP peakmeter, but i can't use in on my main out of my interface, because it is regulated by remote-control.
Because i integrated a bunch of Outboard, i am low on alalog-outputs. i don't want to spend two for the meter.  Now i decided to use my SPDIF out, because i don't use it very often. Is there any cheap D/A-Converter-Chip to do it?
i found this one, which fit my needs, but i think there could be a cheaper solution:

http://www.reichelt.de/A-V-Kabel-Toslink-LWL-/WANDLER-D-A/3//index.html?ACTION=3&GROUPID=3614&ARTICLE=115282&SHOW=1&START=0&OFFSET=16&&SID=33T7SnVX8AAAIAAG7o5Ak978e8b58c9298c43c182c1158be75094&LANGUAGE=EN


Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #1 on: September 07, 2012, 03:46:08 PM »
I have something in development, but it'll be a little more than 34 euro... (and higher performance from the looks of things)

/R
Expat Audio Home: http://www.expataudio.com

dryman

Re: Simple SPDIF-D/A-Converter needed
« Reply #2 on: September 07, 2012, 04:05:26 PM »
Could you be a little bit more verbose, please. Maybe it is usefull for me.

Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #3 on: September 07, 2012, 04:21:06 PM »
Expat Audio have a 112dB S/PDIF input DAC in development. It'll be a module that you simply make a power supply, and a enclosure for.

Early days yet. Am currently debugging boards.

/R
Expat Audio Home: http://www.expataudio.com

12volts

Re: Simple SPDIF-D/A-Converter needed
« Reply #4 on: September 07, 2012, 04:52:22 PM »
This might be worth a looking at. S/PDIF metering, the article can be selected English or German.
The guy has done some wonderful designs. Worth a read even if you do nothing about building.

http://www.beis.de/Elektronik/DPLCM/DPLCM.html


Frank B

Nele

Re: Simple SPDIF-D/A-Converter needed
« Reply #5 on: September 07, 2012, 05:21:56 PM »
I built this one a few weeks ago. The GB is now closed but maybe there is going to be another one. It sounds very nice!

es9023-wm8804 DAC

Kingston

Re: Simple SPDIF-D/A-Converter needed
« Reply #6 on: September 09, 2012, 06:20:02 PM »
Expat Audio have a 112dB S/PDIF input DAC in development. It'll be a module that you simply make a power supply, and a enclosure for.

Early days yet. Am currently debugging boards.

/R

care to reveal any specs? Most curious what analog output options there are. I'm on the market for a better than "pretty good" S/PDIF D/A converter. I've even have some spare "super regulators" for the PSU.

Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #7 on: September 10, 2012, 10:39:19 AM »
Hello Kingston,

the first one will be a simple S/PDIF to single ended 2VRMS output. It's based on a DIR9001 (up to 96kHz) and a PCM5102. (112dB 2VRMS Charge Pump DAC).

Main use will be to take advantage of the extra outputs available on many soundcards. (e.g. quite a few of the m-audio cards have an additional S/PDIF output that people don't have DAC's to do anything with!)

Once I have those in production (with a good yield and performance) then I'll consider something higher end.

Cheers

Dafydd
 
Expat Audio Home: http://www.expataudio.com

Kingston

Re: Simple SPDIF-D/A-Converter needed
« Reply #8 on: September 10, 2012, 11:00:58 AM »
Main use will be to take advantage of the extra outputs available on many soundcards. (e.g. quite a few of the m-audio cards have an additional S/PDIF output that people don't have DAC's to do anything with!)

This is exactly why I need one. PCM5102 simplifies things a lot and is probably very high quality throughout. The analog output impedance is a bit weak at 1k so I would need to soup it up with a balanced line driver, or perhaps a transformer driver. Too bad this complicates the PSU as a single 3V3 supply for PCM5102 is very nice indeed.

Looking forward to this project.

Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #9 on: September 10, 2012, 11:37:57 AM »
PCM5102 is my baby ;) (I defined it here at TI, and worked with the design team to get it out the door).

1K output impedance was specified, as the Dolby and JEITA specifications for home audio equipment specifies an input impedance of 10K (for Dolby) and 22K for JEITA. (if memory serves, I'm open to being corrected... it was a few years ago).

With the majority of systems supporting this model (voltage transfer, rather than power transfer), having a larger output driver would cost more $$$$, not only that, but the charge pump circuitry would have to increase in size as well. ($$$$$$$).

Like everything in the semiconductor world, there are compromises made to support as much business as possible (Value = Cost vs. Features)

Thanks for the feedback.

/R

Expat Audio Home: http://www.expataudio.com


Kingston

Re: Simple SPDIF-D/A-Converter needed
« Reply #10 on: September 10, 2012, 12:30:05 PM »
I should have mentioned, I understand perfectly the "lowly" 1k and unbalanced spec. for bridging impedance. I'm just personally balancing between project choices and need ~600ohm to drive many things. There are some very high spec but affordable DAC/headphone amps that drive 1ohm I was planning to use with 600:600 output transformers.

But now this modular PCM5102 project sounds equally promising.

I could just buy a balanced output DAC, but A) where's the fun in that and B) price suddenly doubles or triples for some reason for higher end stuff.

Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #11 on: September 10, 2012, 12:32:57 PM »
you haven't seen the price of the Expat Audio module yet!  8)
(it won't be silly cheap, but it will be fully build and tested before shipping...)
Expat Audio Home: http://www.expataudio.com

strangeandbouncy

Re: Simple SPDIF-D/A-Converter needed
« Reply #12 on: September 25, 2012, 05:14:30 PM »



   . . . go Expat! I am very interested in a dac. I am even more interested in any future hi-end DAC . . .


   any possibility of some ADC action to boot?


      Kindest regards,


         ANdyP
. . . . RUH ROH . . . . .

Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #13 on: September 25, 2012, 05:26:31 PM »
Andy, Andy, Andy,

patience is a virtue, possess it and you'll see
The wait is long, the results are great
and you'll get your ADC.

/R
Expat Audio Home: http://www.expataudio.com

strangeandbouncy

Re: Simple SPDIF-D/A-Converter needed
« Reply #14 on: September 25, 2012, 05:33:41 PM »
wow,


   all this, - and in rhyme . . . !


    . . . and I can be very patient to boot!


    wahay,


       ANdyP
. . . . RUH ROH . . . . .

mhelin

Re: Simple SPDIF-D/A-Converter needed
« Reply #15 on: October 19, 2012, 07:01:41 AM »
Hello Kingston,

the first one will be a simple S/PDIF to single ended 2VRMS output. It's based on a DIR9001 (up to 96kHz) and a PCM5102. (112dB 2VRMS Charge Pump DAC).

Main use will be to take advantage of the extra outputs available on many soundcards. (e.g. quite a few of the m-audio cards have an additional S/PDIF output that people don't have DAC's to do anything with!)

Once I have those in production (with a good yield and performance) then I'll consider something higher end.

Cheers

Dafydd

Please consider using the PCM5142 DAC as it contains the miniDSP core which allowed for implementing DSP speaker crossovers easily. It is also possible to daisy-chain several of these chips (DOUT can be mapped to any GPIO pin and the output can be pre- or post-DSP selected by SDOUT Select register bit). Don't know if you can however use different coefficients for left/right channels.

The pinouts for PCM5102 adn PCM5142 are pretty much compatible apart from 5102 having only 20 pins, also mode selection pins are in different locations, otherwise single PCB could support both ones. Anyway, PCM5142 DAC would be much more interesting one even as single stereo DAC as it could be used also for digital room correction when "integrated" with Room EQ Wizard for an example, see http://www.hometheatershack.com/roomeq/ .
« Last Edit: October 19, 2012, 07:19:02 AM by mhelin »
Mikko

Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #16 on: October 19, 2012, 07:47:34 PM »
Mikko, I think you just memorized my sales pitch for the pcm5142.

To get the real value out of it, the 5142 needs to be programmed via i2c.
That's a whole other kettle of fish!

I might mod the board and put external i2c pins on it.

Would that fit your need?
Expat Audio Home: http://www.expataudio.com

mhelin

Re: Simple SPDIF-D/A-Converter needed
« Reply #17 on: October 21, 2012, 04:07:16 PM »
Mikko, I think you just memorized my sales pitch for the pcm5142.

To get the real value out of it, the 5142 needs to be programmed via i2c.
That's a whole other kettle of fish!

I might mod the board and put external i2c pins on it.

Would that fit your need?

That would be fine. Also I don't see much use for routing the digital signal after DSP processing to the other DAC modules after all. However, a header for configuring the 5142 mode pins would be also needed in addition to the I2C pins.
Mikko

Rochey

Re: Simple SPDIF-D/A-Converter needed
« Reply #18 on: October 21, 2012, 07:45:31 PM »
You wantnthe 5142 on there by default?

I could footprint the 5142, and populate the 5102 by default. similar to what we did on the pcm5102 eval board.

Expat Audio Home: http://www.expataudio.com

mhelin

Re: Simple SPDIF-D/A-Converter needed
« Reply #19 on: October 22, 2012, 05:04:48 AM »
You wantnthe 5142 on there by default?

I could footprint the 5142, and populate the 5102 by default. similar to what we did on the pcm5102 eval board.

Yes do just like that. I didn't notice earlier that larger footprint on the PCM5102 EVM-U, maybe because the $199 price tag.
Mikko


 

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