Hello,
Some of my friends are quite interesting on Topping D900 since Topping shows on CanJam New York 2024. They start to sell D900 since last month but it's weird that Topping pending D900 for a year cause the date code on bar code label shows 202405.
Front panel, the ID is quite simple with touch panel which used same as another DAC like Centaurus.
Back panel, D900 integrated preamp inside so there are two set of XLR on it without RCA.
I think RCA output can be added if only maintain one set of Toslink/Coaxial.
Rest input I2S, AES, Toslink*2, Coaxial*2, 12V trigger, USB type B and one more Type C.
Bottom plate and foot, D900 used aluminum foot pads this time. You may see counterbore holes reserved for rubber foot, fortunately they kept aluminum foot pads.
The remote made by aluminum like DX9, rest are freebies for first batch.
Inside, there are five portions, the left is power supply, middle-left is digital process and input, middle-right is DSM32 module and right are preamp.
PCB bottom side, this is the first time I saw flex clean on PCB, hope Topping may keep improve their build quality of SMT.
Power supply is Meanwell IRM20-15 isolated power, and there are six set of TPS5420 step down for 12V, 4.3V, ±12V and ±8V.
Digital input, 12V trigger on top, BT module on top center. XMOS XU316 on the middle-left and CPLD in the center. Top right is PEQ IC and middle-right is SRC bridge IC with SPDIF receiver function.
The crystal of XMOS XU316 and CPLD used NDK SDA series, which is ultra low phase noise.
After check PCB trace and found those signals and MCLK came from CPLD which means that CPLD re-clock function works for all input.
The top LQF48 IC is for PEQ but didn't know which IC is. The SRC bridge looks like CT7302 which can be used for DSD converter and SPDIF receiver.
MCU came from Synwit, and ultra low noise LDO SGM2209/SGM2211 on the top.
There is an AK4377 blue board which used for display only.
To avoid any impact of sound quality, it used on DAC to decode both PCM and DSD then used MCU ADC to read the output level which is digital date to show on touch screen, like UV display.
DSD signal connect between DSM32 board and main board with IPX coaxial cable, rest power and control signal used pin header. There are 2 set 32-phase bit shift on DSM32 so it will be 64pc of logic gate on it.
Vref made by OPA, although the top marking is removed but I guess this one is OPA1612.
Rest logic gates also remove top marking, suspect Topping is trying to prevent copycat from competitors.
The resistors on string DAC used normal 0402, although there are some 0402 resistors with low temp drift but I can't identify those difference by visual inspection
The clock on DSM32 board used 11.2898 MHz, but I can recognize which brand of it.
You can see I/V board as a big discrete OP, and of cause all ICs polished. I guess the OPA on I/V may be OPA1652 or OPA1656.
The volume control used 9pcs relays per channel, which provide 256steps from -99 to +8dB. You can change 0.5dB or 1dB per step on setup manual.
There are two OPA on preamp, I guess the tiny one is OPA1612 as power supply and bigger one is OPA1656 as gain stage, the whole design may come from A70pro.
The power of resistors matrix also came from OPA1612.
The AC coupling caps used Nichicon MUSE BP 100uF 25V on direct output of DSM32 board.
The temperature of chassis is around 38deg.C (room temp. 33deg.C) after run-in 8hrs.
Take a group photo for both D90MQA and D900 in the end.
Let me know any you have any question on this report, thank you.
Some of my friends are quite interesting on Topping D900 since Topping shows on CanJam New York 2024. They start to sell D900 since last month but it's weird that Topping pending D900 for a year cause the date code on bar code label shows 202405.
Front panel, the ID is quite simple with touch panel which used same as another DAC like Centaurus.
Back panel, D900 integrated preamp inside so there are two set of XLR on it without RCA.
I think RCA output can be added if only maintain one set of Toslink/Coaxial.
Rest input I2S, AES, Toslink*2, Coaxial*2, 12V trigger, USB type B and one more Type C.
Bottom plate and foot, D900 used aluminum foot pads this time. You may see counterbore holes reserved for rubber foot, fortunately they kept aluminum foot pads.
The remote made by aluminum like DX9, rest are freebies for first batch.
Inside, there are five portions, the left is power supply, middle-left is digital process and input, middle-right is DSM32 module and right are preamp.
PCB bottom side, this is the first time I saw flex clean on PCB, hope Topping may keep improve their build quality of SMT.
Power supply is Meanwell IRM20-15 isolated power, and there are six set of TPS5420 step down for 12V, 4.3V, ±12V and ±8V.
Digital input, 12V trigger on top, BT module on top center. XMOS XU316 on the middle-left and CPLD in the center. Top right is PEQ IC and middle-right is SRC bridge IC with SPDIF receiver function.
The crystal of XMOS XU316 and CPLD used NDK SDA series, which is ultra low phase noise.
After check PCB trace and found those signals and MCLK came from CPLD which means that CPLD re-clock function works for all input.
The top LQF48 IC is for PEQ but didn't know which IC is. The SRC bridge looks like CT7302 which can be used for DSD converter and SPDIF receiver.
MCU came from Synwit, and ultra low noise LDO SGM2209/SGM2211 on the top.
There is an AK4377 blue board which used for display only.
To avoid any impact of sound quality, it used on DAC to decode both PCM and DSD then used MCU ADC to read the output level which is digital date to show on touch screen, like UV display.
DSD signal connect between DSM32 board and main board with IPX coaxial cable, rest power and control signal used pin header. There are 2 set 32-phase bit shift on DSM32 so it will be 64pc of logic gate on it.
Vref made by OPA, although the top marking is removed but I guess this one is OPA1612.
Rest logic gates also remove top marking, suspect Topping is trying to prevent copycat from competitors.
The resistors on string DAC used normal 0402, although there are some 0402 resistors with low temp drift but I can't identify those difference by visual inspection
The clock on DSM32 board used 11.2898 MHz, but I can recognize which brand of it.
You can see I/V board as a big discrete OP, and of cause all ICs polished. I guess the OPA on I/V may be OPA1652 or OPA1656.
The volume control used 9pcs relays per channel, which provide 256steps from -99 to +8dB. You can change 0.5dB or 1dB per step on setup manual.
There are two OPA on preamp, I guess the tiny one is OPA1612 as power supply and bigger one is OPA1656 as gain stage, the whole design may come from A70pro.
The power of resistors matrix also came from OPA1612.
The AC coupling caps used Nichicon MUSE BP 100uF 25V on direct output of DSM32 board.
The temperature of chassis is around 38deg.C (room temp. 33deg.C) after run-in 8hrs.
Take a group photo for both D90MQA and D900 in the end.
Let me know any you have any question on this report, thank you.
