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Topping DX9 - teardown

whydan

Member
Joined
Apr 17, 2021
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Hello,

It's kind of surprise to me when knowing that DX9 used AKM AK4499EQ.
We already knew that was a fire broke out AKM foundry on 2020 and they gave up to rebuild on 2021.
AKM chose to be a fabless design house and the new AK4499EX announced on 2023 as outsourcing.

AKM separated AK4499EQ as two ICs, AK4191 as digital processing and AK4499EX as analog converter.
But new AK4499EX only has 2ch output so you can image that AK4499EQ = AK4191+2*AK4499EX.
That's why AK4499EQ is more valuable to me, AK4499EX is more like a cost reduction one.
I have done couple of AK4499EQ DAC teardown report before, so I won’t miss DX9.

Unbox
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DX9 is the 15th anniversary DAC so it is more luxury than others, even the package design.
And also marked 15th anniversary wording on top cover.
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Inside, the DAC, the thank you card, remote control, BT antenna, 3.5 to 6.3 jack, USB cable and hexagonal driver
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The new remote control was built by Aluminum, kind of heavy one.
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The stock hexagonal driver is used to open up remote control
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There is one button with power on/ function on front panel, and two LCD display, knob for volume control, 6.3mm single end headphone output, 4.4mm/XLR balanced headphone output.
Topping put DX9 block diagram on top cover with Acrylic
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It looks nice when power on with orange LED, and it can be turned off if you want.
There is multiple display mode on two LCD display, including UV meter.
It’s really nice to have los of details on this 15th Anniv. DAC even those details would not get any improvement on SQ.
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Full of IO ports on back panel including 2sets of XLR/RCA output (preamp and lineout), HDMI I2S input, 2sets of Cox/Opt, BT SMA jack, USB input, AES input and 12V trigger input/output.
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Base plate, they used metal foot this time better than previously rubber foot.
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Inside DX9, roughly say there is three block. Power on left, digital input/processing in the center and volume control with relay matrix on right side.
DX9 used 6sets new generation NCFA module for headphone amp, two set for single end and four for balanced.
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There are three Meanwell A2D PSU, IRM-15-5 5V for digital power, 2*IRM-20-15 for analog power +/-15V.
It’ not usual to see three PSU on Topping DAC.
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The reg of analog used TPS7A4901 and TPS7A3001, which provided +/- 14V as source, and the headphone amp use +/- 15V directly.
TPS7A4901/3001 are good but not the best, It’s pity that Topping didn’t use LT3045 but I understand that may be shortage risk since LT3094 was short the whole year.
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D2D IC TPS65131 provide +7V as power source of DAC Vref. I didn’t trace the neg power.
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BT module QCC5125 provided BT5.0 LDAC/aptX, kind of old chip.
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USB transceiver used XMOS XU316. SPDIF transceiver used AK4118A, not sure what is the difference between AK4118A and AK4118.
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DX9 still has Altera CPLD for digital process, but no external 45M/49M clock for re-clock this time.
Because it used AK4137EQ for SRC which build-in PLL, it’s my first time to see SRC chip in Topping DAC.
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System control MCU used SYNWIT SWM34SVE16-50. The blue module is unknown one, probably used for FFT monitor I guess. Maybe someone can tell me what is that?
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The keyman AK4499EQ surround by 4pcs of OPA1612 which used to provide Vref 4.75V.
It’s new design from datasheet cause AKM recommend to use 2200uF caps on Vref as LPF, but it can’t add big caps on Vref this time duo to OPA capacitor load capability.
The bottom side IC is ultra-low noise reg AK1118 which provided AVDD 5V. the next one Microne LDO provided 3.3V.
The top side 4pcs OPA1612 are I/V converter and those 4pcs Rubycon YXJ 220uF25V are coupling caps on signal. The right up OP is OPA1612 used to converter as single-end.
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The volume control relay matrix, I am not sure how it works as hybrid but it reduce the numbers of relay and resister.
I can hear the relay sound every 6dB. The headphone amp input buffers are still OPA1612.
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Topping new generation NCFA module, no shielding can and epoxy will be a good news.
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The headphone MOS are nexperia PBSS305NZ/PBSS305PZ
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DC detect used ST OPA 072C
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The backside of PCB, there is less flux than before unless reworked connector. Which means that SMT process got improvement in Topping factory.
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The DAC stack with D90MQA / D90SE and D90 III. Almost all the flagship DAC in Topping.
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Test result, I used E1DA COSMOS ADC+RMAA as quick scan. Topping already provide a specific test report so no need to expend RMAA dashboard.
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Let me know if you have question on this report, thank you.
 
Good job, thanks a lot for sharing the details.
 
Excellent work @whydan, thank you !

Test result, I used E1DA COSMOS ADC+RMAA as quick scan. Topping already provide a specific test report so no need to expend RMAA dashboard.
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Let me know if you have question on this report, thank you.
Just a tip: the crosstalk number suggests that perhaps you left the Cosmos in Mono Mode. The results should be twice as high for a DAC of this class.
 
Excellent work @whydan, thank you !


Just a tip: the crosstalk number suggests that perhaps you left the Cosmos in Mono Mode. The results should be twice as high for a DAC of this class.
Thanks for advice @VintageFlanker , I didn't realize mono / stereo mode before.
And yes, I did use mono mode after read from Ivan's website, the Windows volume is 100% or close to 100% if RMAA needed.
 
And yes, I did use mono mode after read from Ivan's website, the Windows volume is 100% or close to 100% if RMAA needed.
I would advise to use the Cosmos software to set either calibration, A/D filters, and Mono / Stereo (instead of Windows volume) :
;)
 
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