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Hardware Teardown of Topping D30 DAC

Jimmy

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Jun 20, 2018
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#41
That's right, I'm curious because whatever the reason is (cost, availability), they use different XMOS chips and oscillators with every revision, but in every other D30 board I've seen crystal oscillators are used, and the only one that's using silicon based ones is the 10.1, but they seem to be unidentifiable, be it intentional or not (some manufacturers offer that service on request, removing references from components). Anyway unless they are really poor it shouldn't be a problem, there are applications where phase jitter is far more critical than in audio (high speed/bandwith ones), contrary to many people beliefs.

Regarding the board I have exactly the same as the one you measured but with Capxon electrolytics, that I understand are just output caps for the voltage regulators, so if the values are as printed there shouldn't be any problem since they seem to be already over-specced.

Anyway the D30 is a pretty weird design by itself nowadays, since they could have used a more recent (non flagship) DAC chip with 384/768 kHz and higher DSD modes without increasing the price, although the same can be said for far more expensive gear (many Marantz products use CS4398, even their DAC1).
 
Joined
Sep 21, 2018
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#43
Just got warranty unit from dealership for my smoke out from L5-unit. It has repeated JLC going on top of the PCB etc. codes. Anyone else got similar unit? Also L/N is 1810 instead of 1807.
https://jlcpcb.com/about
" JLCPCB (Shenzhen JIALICHUANG Electronic Technology Development Co.,Ltd.), is the largest PCB prototype enterprise in China and a high-tech manufacturer specializing in quick PCB prototype and small-batch PCB production "

fkqeosx33ac21[1].jpg
 

Jimmy

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Joined
Jun 20, 2018
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#44
I have exactly the same revision and markings on mine, it seems to be the same one that amir has reviewed but with xunda instead of nichicon caps.

It seems that there are quite a few revisions, I don't know what's the latest one or the reason for so many changes, although I suspect it may be a combination of cost and component availability more than anything else.

Just got warranty unit from dealership for my smoke out from L5-unit. It has repeated JLC going on top of the PCB etc. codes. Anyone else got similar unit? Also L/N is 1810 instead of 1807.
https://jlcpcb.com/about
" JLCPCB (Shenzhen JIALICHUANG Electronic Technology Development Co.,Ltd.), is the largest PCB prototype enterprise in China and a high-tech manufacturer specializing in quick PCB prototype and small-batch PCB production "

View attachment 20745
 
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Apr 27, 2019
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#46
I don't think this is the architecture Alex. I believe this is a master/slave configuration with the XMOS the master for USB. It generates MCLK for the CD4398 DAC:

View attachment 10041

XMOS needs to know the output clock rate anyway so it runs as a master, driving the CS4398 as clock, creating MCLK signal above.

Alternatively there is a CS8416 which extracts the clock from input and through a MUX drives the CS4398 as a slave just the same.

This is why there is no clock/crystal around the CS4398 at all. They are all near XMOS which is the device that needs them. It, internally then generates the appropriate master clock for CS4398.

Here is the block diagram in Amir-CAD :) :

View attachment 10042

The little circles are the local oscillators for XMOS as I have shown.

Again, I am just guessing at this. I have not tried to trace routes and such. Don, what do you think?
I think this is how it works for clocks. There's a separate, probably 24MHz, clock for the USB side of the XMOS. Then there's a pair of clocks for 44.1/48 and multiples which are used for both the XMOS read side and the DAC. These are likely at 22.5792 and 24.576MHz respectively. In this mode they become the DAC master clock source.
XRHA-2HPA.JPG

In SPDIF mode the CS8416 receiver chip extracts a clock using the on-chip PLL and presumably that is switched into the CS4398 DAC. This is derived from an external free-run clock which will in turn derive from the same two oscillators used for read side in USB mode. This SPDIF-extracted clock can be user-programmed to free-run if lock is lost.
 
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