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Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 KHz

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#9,781
roderickvd said:
Doesn’t the dam require 32-bit audio words? Might need to configure something there. Anecdotal evidence only here: my dam1121 works out-of-the-box for 16-bit 44,1 kHz I2S with moOde 7.
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So I need resampling from 16 to 32 bit depth?

With the scope I have seen the player outputs correctly 16 bit word length since the BCK runs at 1.4112 MHz (16+16 * 44.1kHz).

So I believe the DAM does not support native redbook. Bad thing.
 
#9,783
roderickvd said:
Yes I think so.

Edit: the PCM input is limited to 24 bit and should not need upsampling however the I2S format needs to be 32 bit words.
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I'm a little disappointed, every I2S device support 16 and 32 bit depth, Ian's FIFO and TDA1541 DAC for example.

Even our FIFO Lite supports any I2S bit depth, the FPGA does the math to align the incoming signal to the desired output simply adding trailing zeros.

Maybe the designer should specify the limitation in the user's manual.
 
#9,784
That he should have. Documentation is not complete unfortunately - especially as it is ment for IIY (Integrate It Yourself) projects. But it is evident in many places that it is very hard for an engineer to produce truly usable and complete documentation of ones own design. One know too much about it and lacks the strength and often time to really put oneself into the ignorant users situation. "... If it was hard to design, it should be hard to use" as the saying goes... 🙂

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#9,788
The dam1021 (and dam19x1 and dam1121) do only support 32 bit I2S.... When the code was designed looong time ago, I was in a time crunch and 32 bit only seemed fine...
Anyway, most streamers can be fixed at 32 bit, needed anyway for 24 bit audio....
This was covered looong time ago on this thread, but don't seems like anybody are aware that diyaudio have a search function....
 
#9,789
TNT said:
That he should have. Documentation is not complete unfortunately - especially as it is ment for IIY (Integrate It Yourself) projects. But it is evident in many places that it is very hard for an engineer to produce truly usable and complete documentation of ones own design. One know too much about it and lacks the strength and often time to really put oneself into the ignorant users situation. "... If it was hard to design, it should be hard to use" as the saying goes... 🙂

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Click to expand...

I don't agree, I know one gets tired producing manual and documentation but a professional device should be accompanied by suitable documentation.

And it's not related to the user ignorance because the I2S specification has not the limitation to 32 bit depth:
"The bit clock pulses once for each discrete bit of data on the data lines. The bit clock frequency is the product of the sample rate, the number of bits per channel and the number of channels. So, for example, CD Audio with a sample frequency of 44.1 kHz, with 16 bits of precision and two channels (stereo) has a bit clock frequency of: 44.1 kHz × 16 × 2 = 1.4112 MHz"

In other words the DAM1021 is not I2S compliant.
 
#9,790
soekris said:
The dam1021 (and dam19x1 and dam1121) do only support 32 bit I2S.... When the code was designed looong time ago, I was in a time crunch and 32 bit only seemed fine...
Anyway, most streamers can be fixed at 32 bit, needed anyway for 24 bit audio....
This was covered looong time ago on this thread, but don't seems like anybody are aware that diyaudio have a search function....
Click to expand...

Then I believe you should add the limitation in the user's manual.

One expects to know this from the manual and not from a diyaudio search.
 
#9,797
andrea_mori said:
I don't know what Volumio does, I'm not the designer of the player.

I would add trailing zeros rather than upsampling with interpolation algorithm.
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I believe the description should be enough if one masters the concepts. The use of the word "upsampling" gav it away.

On an other note... In no way is a several hundred pages of forum proper "documentation". Thats not that way to treat customers.

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