A NOS 192/24 DAC with the PCM1794 (and WaveIO USB input)

[tuyen]

Thanks. I will try it.

But I did remember reading this from Doede's site. Does it change anything to what you have suggested?



Mainboard

The 10 position pin headers are used for easy connection with the WaveIO Board. Please note this is a proprietary design, so not according to any standard. The LED signal section is on the main board, but is completely isolated from the other electronics. The WaveIO board is driving the LEDs with 8mA current sources. So any LED can be used, color and light intensity are not relevant. There are LEDs for the sample frequency (Fs = 44.1, 48, 88, 96, 176 and 192 kHz), Host active and Audio stream. Very helpful indications!

[hochopeper]

Originally Posted by tuyen

Thanks. I will try it.

But I did remember reading this from Doede's site. Does it change anything to what you have suggested?

In that case the isolation that I mentioned before isn't an issue, so please ignore that.

I have read somewhere a while ago that some LEDs can be more noisy (in terms of radiated EMI) than others, might be worth looking into that still, once everything else is optimised.

[dddac]

Originally Posted by clivem

Doede,

My kit arrived today. Built and running. I'm intending to put together Salas shunts for both 12V and 5V for the WaveIO, but for the moment WaveIO is powered from USB bus and a quick dig through my junk box earlier turned up a transformer and 12V linear regulator mounted to a heatsink, so that is pressed into temporary service for now.

I am pleasantly surprised. I have only spent a couple of hours listening, but I'm pleasantly surprised!

Hi Clive,

A reaction I heard many times now. it seems this dac really beats expectations... In fact it did beat mine as well. Considered me lucky I see you use the standard Mundorf capacitors, a simple power supply and USB. on both sides there is much gain to be made! looking forward to your further experiments....
also with the pcm1704, specially as you have them lying around

[CFT]

Nice dac, and I enjoyed reading your website dddac!

This reminds me of what I read earlier from John Swenson's work from another forum on 1704 vs 1794 (NOS vs disabled digital filter mode):
Computer Audio Asylum

[clivem]

Originally Posted by dddac

also with the pcm1704, specially as you have them lying around

I think that might have to wait. That I haven't switched off your DAC after a few hours listening and fired up my TDA1541A comfort blanket, says it all really. Don't quote me on this, and of course I am allowed to change my mind if I ever do implement a 1704 daughter-board, but my gut feeling is that 1704 will sound more "digital" than what you have now. There is a naturalness, a kind of organic nature, which reminds me more of old-school Burr Brown and Philips chips, more than anything else I have heard which has a sigma-delta badge, or even 1704 for that matter.

I will post some more later. But I had a most interesting time last night with mpd upsampling 44.1/16 CD rips to 176.4. (I don't have a great deal of >44.1k material, so was just playing with software upsampling redbook to 88.2 and 176.4 on the laptop.) Since then I have installed Triode's EDO plugin and kernel on my Logitech Touch (for USB DAC support and > 96k sample rate support) and currently have the DAC hooked up to that. The idea being that I could after editing a config file on the server, use sox or ssrc, to up/over sample on-the-fly. Only problem with that is that I can't go above 96k at the moment due to the Touch using wireless network. Doesn't have the bandwidth to support 176k sample rates. I'll hook up via ethernet later. Reading the John Swenson post, (linked above), I think he is onto something. If you are going to OS and DF, you can get better results doing it in software, not the filters built into the chips.

[Lorien]

I hope it's not too late to bring congratulations to Doede for his work in building this "one of a kind" DAC! I came to the idea that I must have one here to play with so, Doede, soon enough please cont me in for one of your "creations". One is a generic word... I must look around to see how many PCMs I have since I like towers... (higher => better) I'm speaking about towers anyway, so I have a question for you Doede: how many decks do I need and where should I stop counting
Congratulations again for a beautiful design,
L

[jeremysk]

Lorien: Please more info about Daughter card for WaveIO.

[jeremysk]

Lorien, Please more info for Daughter card for WaveIO. What is it used?

[clivem]

Originally Posted by jeremysk

Lorien: Please more info about Daughter card for WaveIO.

Lorien posted some info here.

[dddac]

Originally Posted by CFT

Nice dac, and I enjoyed reading your website dddac!

This reminds me of what I read earlier from John Swenson's work from another forum on 1704 vs 1794 (NOS vs disabled digital filter mode):
Computer Audio Asylum

thanks for feedback. I checked the article from John and it was interesting in terms of getting keen on doing some next experiments with software filtering and up sampling and use some other players. Actually I never tried to listen and measure what happens if you up sample 44.1 to 176.4 or 192 and how it sounds or measure.

this week I finally get my new toy, an AP system two, so I am hoping to get some more insight by doing signal tests as well.

On a sad notice, if you read the thread of John, there is a lot of talking and opinions, but no real DIY which provides an easy route in improving sound for most hobbyists.... Nice for reading time, but not for "listening time"