Pc -> Dac, How ?

[wakibaki]

Originally posted by peufeu
yes I'd like to build a community, but...

...that's all she wrote.

w

[peufeu]

wakibaki wrote

I like trolls. Sometimes I do troll myself. It's always fun to annoy other people, so I understand it turns you on...

Yet, we're on the internets. It is a place very different from Real Life. In Real Life, if someone annoys you, you can do stuff like talk loud, or smash them with a steel bar. All you can do here is write in bold. You'll understand therefore that I fail to be impressed by your might

All you can do on the internets is eat your own frustration and end up with an ulcer. If that's your thing, then I'm glad to help.

Anyway. To everyone except the idiot, thanks for the posts, there is some good info here...

I'm not too interested in single board linux computers, because I'd like to try some DSP stuff like custom oversampling, and a FPGA is good at this. Will it yield a useful result ? I don't know... that's why I want to try.

Also, you have a chicken and egg problem : if a given single board computer is powerful enough to do interesting things, then it will be comparable to a PC wrt noise and complexity...

> IMHO the quality and accuracy of the digital filter has
> more impact than HOW you remove/de-correlate jitter
> spurs.

Which makes me even more interested in trying various impulse responses.

I'm thinking about the usual sinc response, with various lengths (lots of taps or a little), then maybe try a phase-shifted response so the pre-echos don't happen, then some slow rolloffs...

Pjotr, in your experience, is it the impulse response, the number of taps, the arithmetic precision, dither and truncation, that matter most ?... which filters did you like best ?

Some DACs like the new delta-sigmas support an external filter, so you can feed them 1.5 Msps 24-bit data direct to the modulator. I wonder how this will sound. If it sounds better, will it come from the better filtering, or from less noise in the chip ? So many questions...

> I guess any miniPCI-equipped router should be
> powerful enough for 8 channel 192/24 wav ethernet
> playback (netcat?)

NetJack... read about this... it's a really cool piece of software !

Project update : we're arguing about the ways to connect the modules together, it's important to have a system that leaves all the options open. We're getting closer.

> When we test for side bands we are testing the
> system, not the chip.

You're also testing the ADC clock... it's a real can of worms, I can't wait to open it. I'm impatient for the day this thing makes its first analog loopback test, with independent DAC and ADC clocks.

[rfbrw]

Peufeu, perhaps this might slate your thirst for more processing power for a while.

[danny_66]

Hello,

ESS has announced a new DAC: the Sabre32

In the press release they talk about "customizable filter characteristics"
I wonder how much customizing will be available.

http://ca.news.finance.yahoo.com/s/0...rlds-best.html

Regards,

Danny

[Russ White]

Originally posted by danny_66
Hello,

I wonder how much customizing will be available.

Regards,

Danny

Quite a lot.

[Nikola Krivorov]

Hi Peufeu,

I must say it or I will burst - I am waking up every morning checking this thread for news - is there any progress? Is there anything we can help with, man we are truly hoping this thing will happen...

[peufeu]

Well sorry for not posting -- I'm busy having a life and on my free time, taking care of this project. It's advancing, a rough estimation of the first "playing music" stage would be about 1-1.5 months (cause making PCBs takes a bit of time). Basically we're building the basic module set : dac, adc, clock, power supplies, 1 or 2 IVs, that takes time... actually most of it is done, but it's always the last details that take most time ! Don't worry it's going to happen

[mako1138]

Originally posted by rfbrw
Peufeu, perhaps this might slate your thirst for more processing power for a while.

Last time I looked at those Virtex-5s, they were $12k a pop.

[Nikola Krivorov]

Originally posted by peufeu
Well sorry for not posting -- I'm busy having a life and on my free time, taking care of this project. It's advancing, a rough estimation of the first "playing music" stage would be about 1-1.5 months (cause making PCBs takes a bit of time). Basically we're building the basic module set : dac, adc, clock, power supplies, 1 or 2 IVs, that takes time... actually most of it is done, but it's always the last details that take most time ! Don't worry it's going to happen

Hi peufeu
I apologize for writing this, I did not mean to be pushy or demanding, I just wanted to remind that there are people that are really amazed by your projects and the contribution from other people, I do hope this thread will evolve in something magnificent. You have become quite a famous man in the DIY community, you know it


I wish you great time with all your hobbies, we can wait patiently here hoping you get even more inspiration.


P.S. have you seen the movie "Heat" ? Al Pacino has a very memorable scene there, interrogating some guy - he just starting banging on the table shouting "GIMME AL YOU GOT!!! GIMME AL YOU GOT!!!" That's exactly how I feel I am just a guy that enjoys reading these highly intellectual threads, hoping to get a good sounding dac someday, ignore my posts as spam if you like, I am not trying to be offensive or intruding in any way...

[peufeu]

Originally posted by mako1138
Last time I looked at those Virtex-5s, they were $12k a pop.

Makes sense when you want to emulate a million dollar ASIC

Originally posted by Nikola Krivorov
...

Don't worry, I appreciate. I too have high hopes for this project !! I'm quite impatient to get it working. Your quote about HEAT is appropriate