ok, thanks for the reply. will contact the waveio designer and see what he says.
I have build the Dual AK4495 and AK4137...however together with my NewClassD NCDV then there are digital interference so music comes and goes (dropouts and mutes in channels). it is not constanst but happens randomly. I have tried to replace the AK4137 with TwistedPearAudio 4:1 SPDIF MUX but same issue.
NCDV works fine with other analogue input and with TwistedPearAudio MUX, OPUS and IVY combination.
When there is no dropouts then it plays fine and much better than OPUS/IVY combi...
My guess it is some sync issue (MCLK is connect both from AK4138 and MUX) but can't find the issue..J04 and J07 was closed for the MUX not difference on J10,11 on or off.
Any hints to what it can be and how to fix it?
NCDV works fine with other analogue input and with TwistedPearAudio MUX, OPUS and IVY combination.
When there is no dropouts then it plays fine and much better than OPUS/IVY combi...
My guess it is some sync issue (MCLK is connect both from AK4138 and MUX) but can't find the issue..J04 and J07 was closed for the MUX not difference on J10,11 on or off.
Any hints to what it can be and how to fix it?
Have you tried the DAC with another amp? Is it the DAC itself or in the combination with NCDV only?
here's complete functional DAC in chassis if anybody interested, $160 + cost of USB module, shipping and import taxes, excellent bargain if one consider cost of all components presented in this thread and work required to put it together
Now , that's a bargain even if one has to swap out the transformers for 230 v instead of the supplied 220v ones. In Western Australia I get 248v at the outlet so we have to be careful.
Saw the same thing on Aliexpress for a lot more.
Daniel any idea when the designer will release a dual 4497 board for diy?
In case anyone is interested I ran some measurements with different filter settings on my Dual AK4495 DAC connected via USB with the input board from the same manufacturer. They are recorded into a Focusrite 18i20 interface so there will be some influence from that device in the impulse responses but the frequency and phase have been calibrated as can be seen from the straight line from the Scarlett trace.
I have included the traces from an ES9018 for comparison.
As you can see they vary quite a lot. The sharp roll and super slow seem to be the cleanest.
The impulse responses can be seen in this post here
http://www.diyaudio.com/forums/full-range/303417-full-range-tc9-line-array-cnc-cabinet-49.html#post5091167
I have included the traces from an ES9018 for comparison.
As you can see they vary quite a lot. The sharp roll and super slow seem to be the cleanest.
The impulse responses can be seen in this post here
http://www.diyaudio.com/forums/full-range/303417-full-range-tc9-line-array-cnc-cabinet-49.html#post5091167
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If you look at the impulses in the other thread I linked you can see the level of pre and post ringing in the impulse response from the filter used in the DAC. The Sharp and Super slow have the least overall ringing.
The sharp filters have no high frequency roll off in the frequency response, but the slow roll off filters do. Whether any of that matters maybe depends on your point of view, but I was a little surprised by how early the slow roll off filters started.
The phase graph shows where and how the filter affects the phase at high frequencies.
The colours in the graph represent the filters listed in the legend below and the traces have been separated to make it easier to see the responses.
So apart from the effects of the different filters the frequency response is really very good.
I made no claims, I said they have the least overall ringing which they do. What is the best is a more subjective discussion.
I posted the data without much of a description so others can make their own mind up, you were the one who asked for more description so I gave it.
It was more a verification that the different filters do have an effect and I showed how they measure in frequency, phase and impulse.
What do you consider to be theoretically the best filter and why?
Does that match with your preference when listening to them?
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