So is there no way to play the music in its original format (bit perfect)?
Does the music need to be oversampled and filtered?
No way to play non oversampling without any high and low pass filters?
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Although I'm not able to load the filter, I have found 1021filtNewNOS filter, do you think is appropriate to play without any oversampling and DC block?
I'm not a filter expert, that's the reason I'm asking on this thread.
But I would curious to understand the beahvior of the filters when the incoming signal is constant (DC).
How does work the oversampling, how the interpolation does work if the incoming audio words are always the same?
No, there is no way to play non-oversampling. Best you can do is quasi-NOS. I wrote this already in #10358 so like you, I do not understand what is not clear.
Given your obvious expertise in clock design, and I honestly mean that as a compliment, I am surprised you are only finding out about this now.
I think everything has been said about this now, so I will refrain from further comment unless something new is brought up. In fact I think this very post doesn't contain anything new. I just want to be explicit in answering "can it do true NOS" question and hopefully wrap things up.
Given your obvious expertise in clock design, and I honestly mean that as a compliment, I am surprised you are only finding out about this now.
I think everything has been said about this now, so I will refrain from further comment unless something new is brought up. In fact I think this very post doesn't contain anything new. I just want to be explicit in answering "can it do true NOS" question and hopefully wrap things up.
You will have to find out for yourself once you can load a filter file that does not contain biquads for DC filtering i.e. the one you are trying to load. It doesn't matter which of the F4-F7 you use, everything you will be able to play out of the DAC with that filter file loaded will not have DC blocking filter. If you think you can verify that the DAC is "bit perfect" by measuring a DC level out of the DAC you are delusional. Whatever your idea of bit perfect is.
My power amps are soldered to my DACs so I'm not going to test that for you. I wouldn't anyway as I'm not dancing to your pipe. And thats all I have to say about that....
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Sorry, but I'm not a oversampling expert since we don't perform any oversampling in the DACs we are developing, so we have no interest on this.
This is a question of point of views, many think the best way is oversampling at crazy LRCK speed, while we think the best way is playing at the incoming sample rate lowering the LRCK speed that means lower jitter.
Also because there are no problems to perform the oversampling externally (in sotware) if needed.
I have measured the jitter of the DAM1021 LRCK and I have published the plots.
And I did not know the dam1021 is always oversampling.
It didn't necessarily have to be that way since with the FPGA you can do whatever you want, including NOS operation, the simpler process.
Sorry but I have not yet found the time to read more than 1000 pages of this thread.
To stop this endless discussion, I'll share my filter file. It plays bit-perfect, no dc filter, no clipping, tested with an oscilloscope.
Still the problem remains with the download and baud rate.
@Andrea you can test the following: connect to the dam1021 with 9600 baud, start the umanager, change the baud rate to 115200 and try to enter a command.
Still the problem remains with the download and baud rate.
@Andrea you can test the following: connect to the dam1021 with 9600 baud, start the umanager, change the baud rate to 115200 and try to enter a command.
This could be your aha moment…
Soren’s DAC is by design oversampling. IIRC, the R2R ladder operates at 2.8/3Mhz.
I already knew that before I purchased.
If you’re expecting dam1021 to operate in true NOS mode (R2R ladder operating at 44k1/48k), you’re gonna be disappointed…
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Thank you for sharing your files, I believe it's just what I need.
Now I believe I have tried all the possible combinations but there is no way to load the filter.
At this point I believe my board is defective.
And so where is the problem?
We are on a diy audio forum so I like to experiment with the devices I got just in the spirit of diy (although this is a commercial product, but it was presented in a diy audio forum).
So, as I have said several times, I will throw out all the DAC front end and magically it will become pure NOS.
Don't you think it's possible?
If you think so please let me know why.
In the meantime I would like to play bit-perfect and it seems to be possible reading the previous post.
As I expected, as usual your claims are not supported by a technical explanation.
Thanks for sharing! Looking at the coefficients, it couldn't get any more "transparent" I guess 🙂
As perhaps known from the filter brewing thread, I have a keen interest in (quasi-) NOS filters. Do you use this filter for enjoying music (i.e. do you think it sounds good?) or is it just for measurements?
Paul's early "hardcore" NOS filters had a noticeable rasp/grain in the midrange which gumisb's latest NOS filters have fixed, but at the "expense" of being just 1.0 coefficients I guess. Interested to hearing your experience and so perhaps auditioning it myself.
Gosh…shockingly amazing…
Seriously no problem whatsoever!
Please carry on posting whatever….
You should do as you say, cut out and throw away the front end.
Goodbye.
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Unfortunately the problem remains, I have just tried with a 3rd PC battery powered (disconnected from the main AC) and with 10cm cable connected to J3.
The uManager starts and works correctly but there is no way to load the filter.
Now I believe my board is defective or the micro firmware is corrupted.