LCD display for DAC?
Oct 10, 2008 at 9:33 PM Thread Starter Post #1 of 15
Zorlac

Zorlac

500+ Head-Fier
Joined
Apr 6, 2008
Posts
558
Likes
20
Location
WA state
I would like to add a small external LCD display unit to my DAC that will tell me the number of channels, bitdepth, sampling rate, bitrate, etc. for the audio stream being received at the SPDIF (coax and/or optical) input.

I would assume this LCD unit would have a SPDIF input and output. The input would be for the incoming source and the output would go to the DAC.

Does such a device exist? I know that high-end home receivers have this capability built-in to the receiver itself. Do any companies make an external dedicated unit that can be added to a dedicated DAC?

I figured if anyone will know, it would be the DIYers.
wink.gif


Thanks!
 
Oct 11, 2008 at 1:03 AM Post #3 of 15
Wow!...a little too hardcore DIY for me, but that is close to what I'm looking for.

At bare minimum, I want to see bit-depth and sampling rate. I was hoping for something a little more finished/shiny. Not really looking to build something. Just thought you guys might know of a solution that can be purchased already built.

Thanks for the link though!
smily_headphones1.gif


Anyone else have ideas? I would think this would be something desired by others as well. It would be a REALLY nice feature for dedicated headphone DACS. That way you could verify the source is exactly what you expect it to be before it hits the DAC.
 
Oct 11, 2008 at 1:53 AM Post #4 of 15
You wont find a LCD that has a spdif in/out that you can just plug in

Though with some knowledge of microcontrollers, it would be incredibly easy to make one. Most SPDIF receivers (the IC's that convert the SPDIF signal into another digital format that your DAC IC actually uses) these days have software interfaces that allow you to configure and control them with a microcontroller, and it would be a simple matter of reading the relevant registers in the receiver to get the sample rate, bitrate, errors, signal lock, etc. and writing that to an LCD.

I know the CS8416 has both a hardware and software mode, so you can either configure it by setting pins high/low or attaching a micro over a serial connection to configure and query it
 
Oct 11, 2008 at 2:17 AM Post #5 of 15
My KECES DA-131.1 DAC has that chip, but no idea how I would attach a serial cable to it to read the registers.

I'm really suprised that a company has not released some sort of dedicated product like I have described. It seems like a no brainer and much needed for the head-fi crowd among other audiophile groups.
 
Oct 20, 2008 at 4:56 AM Post #6 of 15
I intended to do this with my DAC but didn't get it finished. I think I thought ahead enough to make the relevant hardware connections (plenty of pins available to connect the LCD and the micro can read/write to the SPDIF transceiver registers). Someone would just need to write the correct software for the micro and connect the LCD. I'll be back home mid January so will be able to ship a kit then if interested.
 
Oct 20, 2008 at 12:44 PM Post #7 of 15
Quote:

Originally Posted by Zorlac /img/forum/go_quote.gif
My KECES DA-131.1 DAC has that chip, but no idea how I would attach a serial cable to it to read the registers.

I'm really suprised that a company has not released some sort of dedicated product like I have described. It seems like a no brainer and much needed for the head-fi crowd among other audiophile groups.


because the source is usualy a computer for such groups and such info is available by looking at the screen/settings.
 
Oct 21, 2008 at 6:34 PM Post #8 of 15
Its easy to see what the source is on a computer...yes. But, several things in the chain have the potential of changing the source (i.e. the OS, the media player, the sound card driver, the sound card, etc.).

I want the DAC to report what it is receiving on the SPDIF input so I can prove and verify that I am hearing the source bit perfect. Hopefully this makes a little more sense now.
smily_headphones1.gif
 
Oct 22, 2008 at 3:36 AM Post #10 of 15
I am pretty confident I am getting bit perfect, but again...I want to prove and verify without a doubt that I am by reading the registers directly off the DAC or the SPDIF input on the DAC.

Again, I am suprised this has not been brought up more here.
happy_face1.gif
 
Oct 22, 2008 at 3:45 AM Post #11 of 15
As far as I understand, S/PDIF doesn't actually send any of this information to the receiver. The samplerate is derived from the recovered clock (some receivers can tell you what it is, some can't), the bitrate is zero-padded 20-bit (not totally sure how 24-bit works). Some of this is in the AES subchannel, but not S/PDIF which doesn't define a data structure for the user data bytes.

It's not un-doable by any means, but I think it's a bit more difficult than you're assuming.
 
You must log in or register to reply here.

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)
Back
Top