Hi,
I’m actually studying the structure of the dcd-810 looking at some improvements I could do, and I’m facing some interrogations.
The DCD-810 is basically constituted of an SM5807 low pass filter (4 fold oversampling filter). The serial stream is directed to 2 PCM56H (one for each channel) DACs. On the output of each DAC, there’s a sample&hold circuit.
The S&H is constituted of a demuxer which loads a styroflex capacitor (470pF) with the current output of the DAC. The demuxer is driven by the deglitch signal of the SM5807.
As far as this is a dual DAC architecture, I can’t figure out why this S&H circuit is needed. On an mono-DAC (both L and R samples are alternatively proceeded by the DAC) I can understand the need of S&H when a sample of the other channel is proceeded.
The PCM56 datasheet is clear about this :
So why Denon kept the S&H circuitery even if not needed ?
Many thanks in advance.
I’m actually studying the structure of the dcd-810 looking at some improvements I could do, and I’m facing some interrogations.
The DCD-810 is basically constituted of an SM5807 low pass filter (4 fold oversampling filter). The serial stream is directed to 2 PCM56H (one for each channel) DACs. On the output of each DAC, there’s a sample&hold circuit.
The S&H is constituted of a demuxer which loads a styroflex capacitor (470pF) with the current output of the DAC. The demuxer is driven by the deglitch signal of the SM5807.
As far as this is a dual DAC architecture, I can’t figure out why this S&H circuit is needed. On an mono-DAC (both L and R samples are alternatively proceeded by the DAC) I can understand the need of S&H when a sample of the other channel is proceeded.
The PCM56 datasheet is clear about this :
So why Denon kept the S&H circuitery even if not needed ?
Many thanks in advance.
That's a very good question. My Monarchy Audio 18b DAC is based on 2 x AD1860. It does not have deglitching circuitry.
i have a dcd-800, which has just the one pcm56.
Bought it cheap long ago for it's dac. If you would like to compare, you can have it cheap too. Maybe you live near me (bit north of Aachen).
I did not use the dac, as i needed a pcm54 or 55. The dac lists on the net are incorrect for the dcd-800. 🙄
Bought it cheap long ago for it's dac. If you would like to compare, you can have it cheap too. Maybe you live near me (bit north of Aachen).
I did not use the dac, as i needed a pcm54 or 55. The dac lists on the net are incorrect for the dcd-800. 🙄
Sure that that S&H circuit isn't really just an op-amp low pass filter circuit? In any event, I did this vacuum tube circuit in a CD player that used PCM56's. Sounds quite good.
And everyone I guess by now has seen my web page
Modifying CD player DAC circuits
An externally hosted image should be here but it was not working when we last tested it.
And everyone I guess by now has seen my web page
Modifying CD player DAC circuits
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