Awesome!
Got it combined with the Amanero Combo768 interface (i2s). Sounds better than my Topping D30Pro.

Beats the sigma-delta bunch.
Formerly, i made a project with the ESS flagship ES9039 with reclocker, FIR reconstructor, etc, very ambitious. It was OK, the dynamics and clarity superb, but was a bit too... well over the top, so to speak.
I bought two of these R2R-boards, and just used them as replacements for the ESS chip. I had a multi bit DAC some 15 years, and since then I can't really be friends with the sigma delta types.
With these boards it's like coming home - but with the house freshly painted. The typical superb representation of nuances that renders poetry to the listening session is there. But it's even better than the old PCM1704 I had. These new boards have something the PCM1704 didn't have; a CPLD that cancels away resistor mismatch. This is the new brave DAC world. The old sigma delta devices, used for so many years, days are counted. In the future all audiophile DAC's will be this kind of intelligent R2R design, but probably packaged in one chip.

But the images of how to connect the boards are a bit misleading. The single ended OP-amp schematic is not very recommendable.

I'm giving it just four stars, since I don't really have something to campare it with, at least not other brands of the same type.

amazing
I built my own DAC based on this. It is an amazing piece, worthing every penny... If you can built a DAC use this R2R, unbeatable for price

this is brilliant
made a dac with 3 r2r bords and passive output without opamps ,tried with opamps it sounded dull and bad compared with my dddac, with passive output it beats ny dddac and my friends metrum pavane and a denafrips, they just got beated very bad, the psu used is a 3 stage psu with emi filters and lt3045 in the last stage, lm1084 in first stage and lf80 in second stage, and a lot af b4 15000uf caps in indput and before lt3045, this is the best dac i ever heard

AUDIO-GD DA7 corretto
Not simple but not complicated either. You need to pay attention to the wiring and power supplies and I highly recommend the original ones.
One day of work, triple checking everything, It pretty much worked first time. The sound is basically excellent, but can be improved with some adjustments that I will install in the future. Non semplice ma neanche complicato. Bisogna porre attenzione ai cablaggi e alle alimentazioni che consiglio vivamente le sue originali.
Un giorno di lavoro, ricontrollando tutto tre volte, Ha praticamente funzionato al primo colpo. Il suono, di base ottimo, ma migliorabile con alcuni accorgimenti che intallerò in futuro.