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Old 29th June 2013, 07:19 AM   #1351
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I was asked a question about Najda that I could not answer...

"I've currently got an asynchronous USB DAC, how would I incorporate this or any other device without USB output into the system and keep it asynchronous?"

I'm guessing it does not... What are the benefits of asynchronous in the real world?
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Old 29th June 2013, 10:00 AM   #1352
chaparK is offline chaparK  Luxembourg
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Quote:
Originally Posted by Ryssen View Post
So like txt file it should work.
The curves might look kind of strange but I took them directly from nanodigi (minidsp) and they sounds fine.(PA woofer weak low end)
Except for the Q on the 70hz EQ should be 0.8 but it keeps jumping back to 3.00.

Just hope you can take the EQ from nano digi and use it in Nadja,that woofer curve did look strange..
Hi Ake,

I had a look at your file. The load is properly balanced between the 2 cores and I can't do anything to help. I have several ideas for optimizing the processing, so it might be possible to implement this setup at 192 kHz in the future.

Regarding the Q of shelving filter "jumping back to 3.0": Najda doesn't use the Q factor for these filters, but rather a S parameter, which is proportional to the slope achieved in the transition band in dB/oct. With this convention, the min value for S is 3.0 and the max is 12.0.

Quote:
Originally Posted by Beau View Post
3.3 would be perfect, missed that. Have to take a look at the header pin out again.
I wouldn't do that. Using clean regulated supplies to power leds is a waste. The 3.3V supply is mainly intended for the DSP's IOs. These IOs must be powered before the cores get their 1.2V supply.

Also, here's a quick note about the staging of power supplies:
- When you turn on Najda, a certain amount of current goes through the 3.3V regulator.
- If you draw too much current, the 3.3V regulator will keep the 1.2V regulator in power down.
- The 1.2V regulator will tell the micro that it couldn't start.
- The micro will not boot the DSPs.

Frankly, I would do a couple of tests with a resistor in series with one led and a 5V supply. Keep raising the value of the resistor (you could use a pot) until you're happy with the amount of light the led emits. I suppose you want the buttons to be visible in the dark and that you don't want to illuminate your home with these leds, so you should be able to keep the current low.
Once you have determined the proper resistance value, you can measure the current per led. If you can keep it below 100 mA for all leds, then you can power them from the 5V supply.

Quote:
Originally Posted by Speedysteve7 View Post
I was asked a question about Najda that I could not answer...

"I've currently got an asynchronous USB DAC, how would I incorporate this or any other device without USB output into the system and keep it asynchronous?"

I'm guessing it does not... What are the benefits of asynchronous in the real world?
Hmmm... Honestly I don't understand the question me neither.
If it's just a DAC then you don't need it with Najda - Najda has its own set of DACs.
If the device outputs I2S, then you can connect it to Expansion Port 1 as explained in the manual and stream USB audio straight into the system. This is the preferred option.
If the device has SPDIF out, then you can connect it to one of Najda's SPDIF ins.

My understanding about this asynchronous stuff is that the data collected from the USB line is stored in a buffer and re-clocked onboard. In order to transfer the audio data to another device, you need to transmit a clock as well, so the transmission gets synchronous again. In clear, the asynchronous stuff applies only to the buffering part of the USB device; as soon as you want to use the data, it becomes synchronous again, whether you send it to the onboard DAC or transmit it to another device.
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Old 30th June 2013, 01:00 AM   #1353
zoula is offline zoula  Canada
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Hi Nick,

I've posted a few comments in post #1291 is it something that could be done??? I suppose it could but is it something that you may include in a near future???

Thank you
zoula
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Old 30th June 2013, 10:12 AM   #1354
chaparK is offline chaparK  Luxembourg
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Quote:
Originally Posted by zoula View Post
Hi Nick,

I've posted a few comments in post #1291 is it something that could be done??? I suppose it could but is it something that you may include in a near future???

Thank you
zoula
Ooops, indeed I skipped your post below.

Quote:
Originally Posted by zoula View Post
I really like the new option about custom Biquad. It work ok, but I find it difficult to work with it since you can not from the software see the coefficients that you've enter. It is hard to see really what your doing. Plus there is no way to get you coefficients back once load in the card if you loose your text file. So, what I propose is to have a custom Biquad button that pop a new window with all the coefficients available. It would make adjustment more simple and easy.
Well I don't know. I can't imagine someone typing all the digits for all the coefficients - or even copying and pasting. That's very much error prone.
On the other hand, biquad coefs is not something that you can tweak manually: you need to run the computation again and import the new coefficients.

I however understand what you mean: once you've imported the coefficients, you can only look at the frequency response graph to identify which coefs you have loaded on each channel (note that you could also open the nsf file and check here your coefficients).

I had thought of displaying the coef file name in the setup panels but gave up on that for the following reason: if you modify the file and don't import again the new coefs, then the displayed file name doesn't point to the coefs being used.

I don't know what we can do, we need to think a little further. In any case that's probably a detail: as for now you can import the coefs and view the frequency and phase responses of your coef set. When you have a strong doubt you can still open the setup nsf file, the coefs are clearly displayed as in the example below (10 biquads):

Code:
<Channel Index="0" Source="Left" Pre_Gain="0.0" Post_Gain="0.0" Channel_Invert="0" Delay_Samples="0">
    <XOLP Type="0" CutOff="2000" Order="0"/>
    <XOHP Type="0" CutOff="500" Order="0"/>
    <EQ NumSections="10">
        <Section Type="-1" b0="0.282420306759421980" b1="-0.080995298981152999" b2="0.030521497616177999" a1="1.276247963471800000" a2="0.473684210526315990"/>
        <Section Type="-1" b0="0.868295148759569040" b1="-0.868295148759569040" b2="0.000000000000000000" a1="-0.736590297519136960" a2="-0.000000000000000000"/>
        <Section Type="-1" b0="0.806649233538374030" b1="-1.613298467076750100" b2="0.806649233538374030" a1="-1.576180556918350000" a2="0.650416377235152000"/>
        <Section Type="-1" b0="1.258925411794169900" b1="0.000000000000000000" b2="0.000000000000000000" a1="-0.000000000000000000" a2="-0.000000000000000000"/>
        <Section Type="-1" b0="1.009943679177649900" b1="-1.772507135379189900" b2="0.941848930696213000" a1="-1.772507135379189900" a2="0.951792609873866050"/>
        <Section Type="-1" b0="1.030188660630760000" b1="0.138622768091006990" b2="0.736627115220831020" a1="0.138622768091006990" a2="0.766815775851595990"/>
        <Section Type="-1" b0="1.026624199863180000" b1="-1.465339548271680000" b2="0.767724298581248020" a1="-1.465339548271680000" a2="0.794348498444431010"/>
        <Section Type="-1" b0="0.949884466592574970" b1="-0.523528316553325990" b2="0.418160952352727990" a1="-0.523528316553325990" a2="0.368045418945303020"/>
        <Section Type="-1" b0="0.996497225278577980" b1="-1.922977738712559900" b2="0.969440980029027010" a1="-1.922977738712559900" a2="0.965938205307604990"/>
        <Section Type="-1" b0="1.002360455852320000" b1="-1.950346853363710100" b2="0.986195951276735980" a1="-1.950346853363710100" a2="0.988556407129056010"/>
    </EQ>
</Channel>
Quote:
Also the same way of doing thing could be done with the input and the output graph. This way you can check the progress of what your doing in real time.
Yes, undocking of the graph panels was requested several times. Need to look at that.

Quote:
Also could it be possible to add custom biquad in the crossover section too. I realize that it could be done in the PEQ section but in the case that you want a 8 order low pass and High pass, it will eat up a lot of biquad coefficients, and leave you only 1 or 2 for filtering.
Yes, why not indeed. Or we could increase the number of biquads per channel. Or both. (Cross-overs in the EQ section is not the best idea because of the Bypass switch).

Best,

Nick
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Old 1st July 2013, 03:10 PM   #1355
jcga is offline jcga  France
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Hi,
I've now completed my Najda build :

full symetrical inputs/outputs
Amanero + isolator
+5 & +/-12 linear regulators

Now, it's time to go ahead in the real world...
Attached Images
File Type: jpg Najad_final_1a.jpg (128.0 KB, 630 views)
File Type: jpg Najda_rear_1.jpg (131.6 KB, 603 views)
File Type: jpg Najda_final_top.jpg (460.2 KB, 605 views)
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Old 1st July 2013, 03:12 PM   #1356
jcga is offline jcga  France
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and a few details:
Attached Images
File Type: jpg Led Panel.jpg (154.9 KB, 586 views)
File Type: jpg GC-SYM INBOARD TOP.jpg (312.4 KB, 570 views)
File Type: jpg GC-SYM OUTBOARD TOP.jpg (262.2 KB, 273 views)
File Type: jpg Linear Regulator Bufferboard.jpg (284.7 KB, 280 views)
File Type: jpg Nav Panel.jpg (213.2 KB, 294 views)
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Old 1st July 2013, 03:15 PM   #1357
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Looks great
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Old 1st July 2013, 03:19 PM   #1358
jcga is offline jcga  France
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Quote:
Originally Posted by dahlberg View Post
Looks great
Thanks,
now... waiting for mix FIR-IIR... Hey Nick

JC
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Old 1st July 2013, 05:51 PM   #1359
UrSv is offline UrSv  Sweden
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Yes, that looks very nice indeed.
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Those who say it can't be done should not stop those who are doing it.
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Old 1st July 2013, 06:19 PM   #1360
chaparK is offline chaparK  Luxembourg
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Hi Jean-Claude,

Well, what can I say? I'm speechless Thanks for posting the pics!

Quote:
Originally Posted by jcga View Post
Thanks,
now... waiting for mix FIR-IIR... Hey Nick

JC
Hey JC




Alright, it's coming soon
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