> are C31 and C36 cap vital to sound quality?
Yes.
> any suggestion for this 47p cap?
Fidelity-Audio
Plenty other google hits.
> C31 and C36 are SMD
Easy enough to solder a Styroflex in parallel with R8, R9 on the bottom side.
Cheers,
Patrick
Yes.
> any suggestion for this 47p cap?
Fidelity-Audio
Plenty other google hits.
> C31 and C36 are SMD
Easy enough to solder a Styroflex in parallel with R8, R9 on the bottom side.
Cheers,
Patrick
Just a heads up for beginners, because video that miro posted is a bit misleading 
. On video they cheated (see pins on the left and right side) Most important step is to fix the chip to pcb with third arm or some other creative solutions because SMD parts can float in flux all over the pcb And don't ask how I know
. On video they cheated (see pins on the left and right side) Most important step is to fix the chip to pcb with third arm or some other creative solutions because SMD parts can float in flux all over the pcb And don't ask how I know I did that "dragging" with my muses volume control, however these SO14 chips were a little bigger so decided to solder them leg by leg. Proved to be more work in the end. I like the dragging technique very much except for the fact that my flux is really sticky and hard to remove, even with isopropanol.
My ali china psu's arrived (as a test if they are any good,both 12 and 5v are lm317/lm337).
Exciting!
I turned on my dac today and put 680ohm iv resistors and do not put the caps... so far it sounds good.. [emoji6]
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My ali china psu's arrived (as a test if they are any good,both 12 and 5v are lm317/lm337).
Exciting!
Perfect! Tell us more after an intensive testing. You can also add a few pictures
I'm only able to present some preliminary findings as it's open bench (with temp sensitive reg's) and China-based AD1862's (the ones from Paddy are on their way).
w/o burn-in & LM6171 the sound is really promising!
The current draw is quite low - I expected higher values. I measured around 18,6 mA (A+), 25,9 mA (A-), 6,3mA (D+) and 3,4 mA (D-) when playing. With ~ 110uF decoupling peaks are ~ +/- 1,5 mA in the analog section. But I think my Fluke 289 isn't fast enough to catch the spikes.
The build/testing will slow down from now on. I have to wait for the new RPi/FifoPi mounting pcb and the genuine AD1862 from Paddy. Also I noticed yesterday that the smd-adaptors I have lying around can't be safely used with 49990 due to the bottom pad. In addition I'm somewhat fixed on trying out the discrete I/V from EUVL. But I have to design a pcb first and get some parts - it never stops ...
I have OPA1656, OPA1611, OPA810, OPA861 at home - any recommendations what to try next?
w/o burn-in & LM6171 the sound is really promising!
The current draw is quite low - I expected higher values. I measured around 18,6 mA (A+), 25,9 mA (A-), 6,3mA (D+) and 3,4 mA (D-) when playing. With ~ 110uF decoupling peaks are ~ +/- 1,5 mA in the analog section. But I think my Fluke 289 isn't fast enough to catch the spikes.
The build/testing will slow down from now on. I have to wait for the new RPi/FifoPi mounting pcb and the genuine AD1862 from Paddy. Also I noticed yesterday that the smd-adaptors I have lying around can't be safely used with 49990 due to the bottom pad. In addition I'm somewhat fixed on trying out the discrete I/V from EUVL. But I have to design a pcb first and get some parts - it never stops ...
I have OPA1656, OPA1611, OPA810, OPA861 at home - any recommendations what to try next?