I have found another board that seems to be neat. Shunt dual PSU for IV stage and separate supply for each digital part.
ES9028 ES9028PRO /ES9018 ES9018S Q8 HiFi Audio DAC Decoder DIY KIT | eBay
ES9028 ES9028PRO /ES9018 ES9018S Q8 HiFi Audio DAC Decoder DIY KIT | eBay
Maybe consider the following board with ES9028PRO pre-installed. The rest you stuff yourself as you see fit. I have one to experiment with, and the first thing I did was sketch out a schematic for their design. With that, I would probably change their AVCC Vref divider, and maybe change some of the output stage. Probably also possible to get two more channels out of it for a total of four, with a little bit of tiny, but doable soldering (using small tip). Very mod-able in my view. ES9028PRO ES9018 32bit Audio DAC PCB - DIYINHK
I've been looking at that board, did you write about it in one of your threads Mark?
I only mentioned the board briefly and posted some clear pictures of both sides of the PCB in case anyone wanted to see better pics than on the seller's website.
It was something I wanted to try out at some point as a PRO type Sabre dac project. In particular, I know '38PRO has an option for 256-tap interpolation filters. Not sure about '28 since I don't have a data sheet for that one. Be interested to find out if it has the filter option.
It was something I wanted to try out at some point as a PRO type Sabre dac project. In particular, I know '38PRO has an option for 256-tap interpolation filters. Not sure about '28 since I don't have a data sheet for that one. Be interested to find out if it has the filter option.
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to me it looks easier to mod, and it also looks like 2-layer.
the semifinal mod for the one with 4-layers in 1st post ended up pretty well.
probably the best sounding DAC in my procession at the moment.
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yes it can do 256 taps. I think both 28pro and 38pro share the same digital core.
Could you share with us the mods you made to the DAC board? The THD plot looks great!
1. I/V opa1612. FB resistor: since ES chips have allowance +/-15% in output current, then aiming for about 3.2V, resistor values can be 205-250ohm. most importantly 0.1% and low T drift.
2. LPF opa1611. I went for high ohmic one, kind of compromise between noise and distortion. you can get an idea from the cartoon attached. resistors the best you can get and FKP2 wimas
3. AVCC and +/-15V: Nazar's shunts. I do not appreciate LDOs impedance curves and load transients. you may have another option but these appear to me sonically superior.
4. Digital on LT3045.
5. Clock NZ2520SD 3.3V 20ppm 80.0000MHz (size 2.5mmx2mm) on dedicated LT3042
kind of missing:
1. USB galvanic isolation and reclocking
2. register tweaking
playback: hqplayer on the fly upsampling either to DSD256, closed-form filter or PCM as high as possible with gauss1
anyway, the sound is gorgeous now ...
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I am pretty much in with you on this one. I have been too busy to complete my mods . But at this time I am living with the same opa1611 and opa1612. I reassessed the current boosted opa1611 and returned to the opa1611. Jung Super regs using LME49710s power the op amps.
The LT3042 is strictly for the clock and digital. The AVCC is still being fed from an AD817 based Sulzer with polypropylene caps. I abandoned the AD797 on AVCC, it did not sound as sweet as the AD817 which is so smooth yet quite detailed. Crystek Clock. The LT3042/45 can't cut it on AVCC according to my ears. It sounds ultra buttery but it lacks details and dynamics. It flattens the vocals where it loses the 3D quality. Like Ezitis, it appears to fall on transient loads. Steady current requirements is possibly where it is best suited...l
Been too busy to complete the LTC6655 in a super reg for AVCC. I have all the parts though.
Sound is so good, I am in no hurry to continue mods right away.
But there is very little to complain about with the DAC as modded to date. I am sure so resistor swaps and cap swaps might improve things a touch but it sounds so good, it is not a priority.
I am using the AD744 - AD811 fed by Super Regs for my preamp.
I would say Jung/Sulzer should be pretty good for opamps/AVCC power. so far I remember they are series ones with an opamp as error amp, right. I tried similar topology and measurement wise they were fine. Important here is an RC filter (or even 2) after reference. however, I went for shunts, setting idle current as much it is thermally reasonable because they sounded better (not necessary will sound better elsewhere). btw elcaps left original, are they fake or not. measured a couple, and they were fine.
Shunts with high currents according to my understanding might be technically superior. The ground currents are supposed to be better controlled and cause less chaos on the lines. Since I have what I have, I have reached a point with how busy I am, I am content.
It is apparently quite simple to reconfigure a Jung Super Reg into a shunt arrangement complete with remote sensing. Maybe one day.
For the time being I'm happy with the sound I have now.
It is apparently quite simple to reconfigure a Jung Super Reg into a shunt arrangement complete with remote sensing. Maybe one day.
For the time being I'm happy with the sound I have now.
a comprehensive, (possibly a little biased) shunt description for audio one can find here:
Shunt or Not - Looking for the Ultimate Audio Voltage Regulator | audioXpress
not sure they are technically so superior, but clearly thermally inferior. however such a low and flat output impedance perhaps is something exclusive...
Shunt or Not - Looking for the Ultimate Audio Voltage Regulator | audioXpress
not sure they are technically so superior, but clearly thermally inferior. however such a low and flat output impedance perhaps is something exclusive...
my recommendation would be to take a look at Nazars shunts: simple, cheap, compact with excellent performance. I provided a bit more info on them elsewhere: ES9038Q2M Board and bellow. there is also some further development of them.
anyway, they pretty well integrate on the top and could be placed close to the load.
anyway, they pretty well integrate on the top and could be placed close to the load.
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Is there a link where this shunt can be acquired? I like the aspect it can be installed locally as I am running out of real estate in my case.
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