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#9038D

According to multiple headfiers requests: 3.5mm jack unbalanced output DAC+HPA 180mW@32ohm in the same case as #9038SG3. The same as 9038SG3, 9038D will work with Tweak app. The DAC has virtually zero noise modulation behavior. 

Specifications(TBD):

Status:                            production

Materials:                       sandblasted/black anodized aluminum/laser mark/ES9038Q2M/OPA1622/OPA1602

                                        Susumu resistors, Murata C0G caps, AVX tantalum caps, Taiwanese connectors

Dimensions:                   48x22x9mm


Weight:                           12g


Power:                             USB +5V rail no internal battery, 95mA idle current, the device                                                                                           contains >4000uF of capacitance for the power rails filtering

                                         Note: 9038D6K 6000uF 105mA idle current


Input:                               USB-C, PCM up to 32b/384kHz, DSD256

                                         USB bridge Comtrue CT7601CR custom FW


Output:                            standard unbalanced output 3.5mm jack, HW volume control .5db/step


Output impedance:       .07 Ohm@1000Hz Agilent U1733C

Output power:                180mW@32 Ohm@1kHz@THD=1%                                         

                                         120mW@16 Ohm@1kHz@THD=1%

                                         measured at +.5dbFS level, typical PC USB2 port powered 

                                         the hot unit produces less power

Frequency response:   5-80kHz +.05/-1db@ 32b/384kHz


SNR=DR@50MHz_MCLK:                      125db(A) typical, referenced to 2.75VRMS

 from the second batch 100% units are calibrated with the result printed on the case, >123db(A) is normal grade

 Note: 9038D6K 126db(A); units are individually calibrated, see the result printed on the case.  >124db(A) is a normal grade. Please note, any user with Cosmos APU may calibrate 9038D by themself for particular headphones.

THD+N@1kHz@-.5dbFS BW 22-22kHz   .00014%, SINAD 117db typical for 24b/44.1kHz@no-load

Note: 9038D6K a typical SINAD 118-120db+


THD@1kHz@-.5dbFS BW 22-22kHz   <.0001% typical for 24b/44.1kHz@no-load

THD+N@1kHz@-2.5dbFS BW 22-22kHz  .00018%, SINAD 115db typical 24b/44.1kHz@32ohm

THD+N@1kHz@-7dbFS BW 22-22kHz  .0005% typical for 24b/44.1kHz@16ohm(-6dbfs correspods 120mW)

Crosstalk:                     -135db@1kHz no-load, -82db@1kHz 32ohm load

 The Windows driver is here.

 FW tools are here

After ios17 the compatibility Android vs ios was broken, and our DACs flashed for Android need to reflash for ios17_FW if you gonna use ios-devices. The tutorial is here.

Warning: 9038D contains a high-sensitive I/V stage that may cause audible noise when your phone uses LTE  4G, 5g. 

Tech appendix

Conventional PC USB2 port, 10Kohm vs 32ohm loads THD+N 

Conventional PC USB2 port, 10Kohm load THD+N vs time 

Conventional PC USB2 port, 32ohm load THD+N vs time 

Conventional PC USB2 port, AES17 Dynamic Range A-weighted vs time 

Frequency response PCM384 Slow Lin. Phase filter 10-40000Hz at -0.2db

Nearly ideal square wave 1kHz PCM384 Slow Lin.Phase filter at 200MHz BW scope

Square wave 1kHz PCM192 Slow Lin.Phase filter at 200MHz BW scope

Square wave 1kHz PCM96 Slow Lin.Phase filter at 200MHz BW scope

Square wave 1kHz PCM44.1 Slow Lin.Phase filter at 200MHz BW scope

24b/44.1kHz 1kHz -0.5dbfs FFT no load

24b/44.1kHz 1kHz -2dbfs 150mW FFT 32ohm load

24b/44.1kHz 1kHz -2dbfs 40mW FFT 32ohm load

24b/48kHz 12kHz -2dbfs FFT no load

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