ALL digital DSP (in & out)... What are the options?

[TNT]

Hm... In NOS DAC? No sin(x)/x frequency response shaping?
Also ovesampling DACs filters with constant # of taps sound a bit differently as the transients (ringing) has the same length in samples, but different in the real time

Well if there isn't an integrating network, the only thing you hear is noise.

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[stolbovoy]

All of those things have to do with the processing of the sampled audio, not the audio itself.

Yes, and this thread is about choosing processing implementation, isn't it?

 

[stolbovoy]

Well if there isn't an integrating network, the only thing you hear is noise.
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Do you mean that R-2R DACS will not produce ... legible sound if the output played though hypothetical loudspeaker that doesn't act as an integrating network? Or that NOS means absence of the filtering in analog domain?

 

[JMF11]

I have the stm32f769 disco board, and it rocks. You might consider it... spdif in and out, with a touchscreen and sd card slot for storage. Total cost is 80 bucks from mouser.

I bobthedespot,

I'm currently exploring the possibilities offers by the stm32 MCUs (F4, F7), and consider using some associated Nucleo boards. I'm working at the moment with the Stm32F4 discovery

Have you developped some audio application on those processors? Would you share some of the code?

I try to achieve (full digital) Async USB=> DSP => SPDIF or I2S.

Best regards,

JMF

 

[stolbovoy]

I wonder if PIC32MZ is enough to build 4 way crossover running at 192kHz? I've used PICs before and TQFP is more DIY friendly.

 

[cogeniac]

1,2) It is not about stereo image, but yes if there are different clocks my tweeter may be ahead or behind of mid-range due to ASRC. Probably not by a lot, but still can. Spending considerable amount of efforts to clock everything from one clock source (DAC) it sounds less then optimal solution.
3) If DAC itself is NOS than 192 is better. And also - why not? If my PC can do it without an effort, why should I us inferior solution that will cost me $1300 more?

If you use something like the MiniDSP MiniSHARC (yes, it is "only" 24/96), you clock the HF and LF channels out using the SHARC MCLK, so all of the channels are synchronous (the DACS are all driven by the same clock).

Put the SHARC on the input side of the SHARC, and use it to rate convert all of the various input formats to 24/96, and to elect from the different input sources.

The SHARC can handle additional channels, but for very additional channel, you will have fewer digital filter taps, and thus less resolution in the filters.