DSP Xover project (part 2)

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#3,042
Currently I'm running the Najda with the WaveI/O as an I2S input.
I have a MiniDSP miniSHARC board I'd like to insert between them for FIR phase linearization of individual channels.
It looks pretty straightforward... has anyone done this?
Potential snag: will Nadja volume control work globally on all I2S inputs?
 
#3,043
One more thought... taking a closer look at the miniDSP SHARC and Najda software, it looks like it would be best to use the SHARC as an 8 channel FIR + IIR linear phase crossover, and the Najda as a room correction engine. Is there any real difference in the implementation of these filters between different platforms, in other words, is one "better" at filtering than another? (The miniDSP uses Analog Devices SHARC ADSP21369, 32 bit floating) Thanks.
 
#3,049
Hello Bengt,

Thanks for your email and sorry for the late reply.

I'm currently in the process of relocating the office, I'm moving back
to Poland.
I do have control kits in stock, however I'm not going to be able to
ship anything before I'm done with moving and unpacking.
Cable length is 20 cm - I don't have any 40 cm ones unfortunately.

Cheers,

Nick
Click to expand...

I got this mail a few weeks ago.
 
#3,052
Output to NOS PCM1794 DAC

I am trying to get the Najda I2S Audio Data Out to interface with an NOS DDDAC which uses a PCM1794 DAC and requires right-justified 24-bit DATA in NOS mode. The DDDAC main board converts a standard I2S signal to right-justified by shifting the data 7 bits. I am using a high speed galvanic isolation buffer between Expansion Port 0 and the DAC.

I am getting no sound even though I can trace DATA, LRCK, and BCLK bits going into the PCM1794 chips. A scope display of the DATA coming out of pin 24 shows a repetitive pattern even though I am playing music which should give a random smeared scope display. Do I need to connect any of the following to get sound?

26 GPIO_EXT00 GPIO Ext0 Line 0
27 IS_EXT0\ Detect expansion board
28 GPIO_EXT01 GPIO Ext0 Line 1

The Najda Startup Guide states "Data format is 64 bit clocks per sampling period, organized in two 32-bit time-slots with msb of 24-bit data aligned to the left.” If so, I need to delay the data one more bit since the standard I2S already has one clock bit of delay.

I appreciate some help with this.....Thanks
 
#3,053
NOS PCM1794 finally playing music.

Getting music through my NOS PCM1794 DAC now. I'm not sure what my problem was earlier but I kept fussing with it and taking a zillion measurements and scope displays.

I still need to get an answer to the question:
The Najda Startup Guide states "Data format is 64 bit clocks per sampling period, organized in two 32-bit time-slots with msb of 24-bit data aligned to the left.” If so, I need to delay the data one more bit since the standard I2S already has one clock bit of delay.
Click to expand...
 
#3,055
User interface question

Could a Najda owner tell me whether it is possible to use a remote control to i) increase / lower the volume with "up/down" ii) change source with "left/right" keys on a remote.
I am asking, because for family use, those two functions should always be accessible, but menus, preset selction etc. are irrelevant and we do not want to scroll through various options before being able to adjust the volume.

Thanks for any answer!


PS: Would it be a bad idea to install a display /control board inside the box only remote receiver accessible. I can open the box when tinkering with the system. Most of the time it should just run with only volume (potentially mute) and source selection available to the user. Can one restrict source selection to switch only between connected channels (e.g. optical and analogue)

PPS: I found the youtube review of jipihorn interesting (even though my French is not the best), it is the only place on the internet that I have seen comprehensive measurments (THD, noise level, jitter) on Najda posted. I find it curious it was never mentioned on this thread.
 
#3,056
yoshisoakland said:
PPS: I found the youtube review of jipihorn interesting (even though my French is not the best), it is the only place on the internet that I have seen comprehensive measurments (THD, noise level, jitter) on Najda posted. I find it curious it was never mentioned on this thread.
Click to expand...

Thanks for the information. Could you post a link, please?

Edit: I see that there are at least 3 videos that come up, searching for Najda.
 
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#3,058
yoshisoakland said:
Could a Najda owner tell me whether it is possible to use a remote control to i) increase / lower the volume with "up/down" ii) change source with "left/right" keys on a remote.
I am asking, because for family use, those two functions should always be accessible, but menus, preset selction etc. are irrelevant and we do not want to scroll through various options before being able to adjust the volume.

Thanks for any answer!
Click to expand...

You can do exactly that (with Nick's front panel board) as you get to select which buttons are assigned to which functions when you set the front panel remote up. Download the manual and it explains how to do it.

PS: Would it be a bad idea to install a display /control board inside the box only remote receiver accessible. I can open the box when tinkering with the system. Most of the time it should just run with only volume (potentially mute) and source selection available to the user. Can one restrict source selection to switch only between connected channels (e.g. optical and analogue)
Click to expand...

I did exactly that with mine. I cut up the front panel board and have the switches separate. If I need to reprogram the Najda then I open up the box and plug it in to change the settings and then put it back in the cupboard. I posted some photos here http://www.diyaudio.com/forums/digital-line-level/215379-dsp-xover-project-part-2-a-244.html#post4107643 posts #2436 and 2437
 
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