Ok for my AB tests of DAC, the setups are DACs (Topping D10s and Audio-GD R2R11), using Topping L30 as amp. The setup is as below:
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Both of DACs are connected to a switch as inputs and the out of the switch is connected to input of amp. Hiby R5 provide the tone and music via usb to D10s and the coax out of D10s connect to coax in of Audio-GD R2R11. The voltages measured using 1khz tone:
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I had to tune the R2R11 volume using its variable volume mode but I couldn't really get to the output of D10s but methinks close enough, right?
Based on the music I listened to basically pop songs, when switching between the DACs , I couldn't really tell any difference between them. To me they sound the same so I decided not to do blind testing.
Moving forward from this, I will proceed with amp AB testing next.