Using one/two RC filter. at OP input, you do not need LT3045 or similar - you can use any regulator (some LDO that is already exists in your design, 7803, LP5907, zenner).
Alex.
As I am working with ready made boards (AK4490 to 4497, ES 9038 and ES9039 I usually attach the LDO right to the ceramic decopling cap or if to small to the big decopling cap. The wire is most of the time no longer than 5mm. I got no RF concerns using this approach.
For the opamp adapter boards I gonna use bare boards with no pins. This will get me really close to the decopling caps of the chips to be fed.
I got 7 double LT3045 boards that's why I gonna use them. On some I cut the trace that parallels the two chips and used them that way as two single LDOs.
...while taking into account that subsonic noise gets mixed into the audio band as soon as you play music through the DAC - although it should then also get masked by the music.
I tried to reduce 1/f and got exactly nothing changed what I could detect. FFT skirt is the same, distortions also. At the same time, 1612(1.1nV/Hz^.5) in Cosmos ADC gives a lower noise vs 1602(2.5nV/Hz^.5).
Mine is the same, about -135db but dual-mode is still worse and not only about 1k H3. BTW, I tried to sum Left+Right by simple shorting,
and get just 1db(132 vs 133db(A) worse noise than summed by beads. 9039pro seems more sensitive for shorting DACs, as I remember, the difference was 133 vs 137db(A).
and get just 1db(132 vs 133db(A) worse noise than summed by beads. 9039pro seems more sensitive for shorting DACs, as I remember, the difference was 133 vs 137db(A).
If you don't see lower FFT skirts with low 1/f noise the problem may be your ADC. The same thing applies to ES9822PRO AVCC supplies (all three).
It doesn't really matter, my first problem now is a so-so performance of dual 9039q2m.. too high H11 and H13 if CLK GEAR SELECT = 0, 1 or 2 is a lot cleaner but the noise is higher too, so I have THD+N limited by the high order harmonics or by noise.
For measurement purposes even single ES9039Q2M works well as the THD compensation is channel-specific. Mono-mode may actually have worse performance depending on how well the summed channels are matched.