Cheap SA9027 + ES9023 (or PCM5102) DAC, anyone try?

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I ended up buying two of these because I was so impressed with the sound quality and the fact that it is a USB 32/384 solution that can pretty much play anything PCM.

I have removed 10uf caps for a cleaner output and use a USB splitter cable to provide a cleaner 5V supply. At home I use a linear power supply:

HiFi PSU 15VA DC5V 2.0A high-end Linear Power supply with USB port for XMOS 6631 | eBay

and at work I just use a mobile phone power pack to supply 5V. In both instances the voltage pin on the PC connection is taped over to stop any nasties reaching the DAC.

Bother solutions work well but the weak link in the DAC are two AMS1117-3.3 regulators which feed PCM5102A. I replaced these with LT1963EST-3.3 which have much lower noise and transform the DAC completely even if the pin-outs on these regulators differ slighlty.
 
Did you add caps to the regulators, as suggested earlier in this thread.
Would you mind posting a picture of your mods?

Hi,

I've remove the two line driver output capacitor of 10uf and solder it into the regulator.

One at the input(5v) of ams1117 regulator near SA9227

Another at the output(3.3v) of AMS1117 regulator at PCM5102A

I wonder the capacitor for the audio output is suitable but it has a negative marking. I assume its suitable. So far it works fine

I don't have any measurement but in theory it will work

Regarding the sound, I couldn't tell much differences since I don't another unit to A/B test. But it sounded more dynamic and bass
 
Since the original post I have now gone a step further.

I built two of these 3.3v kits powered by a dual 6v AC toroidal transformer:

1.0uV Ultralow noise DAC power supply regulator 3.3V 5.0V 800mA - DIYINHK

The two onboard regulators have now been bypassed and the both the PCM5102a and the SA9227 are powered directly by the off board kits instead, and the 5v usb pin on the PC cable taped over.

It's all waiting to go in a case, but sound is very smooth and detailed with extended clean bass.
 
I have this DAC that combines the SA9023 and ES9023 and it sounds very good for the price. I notice that they have the two 10uf caps [see attached pics] so my question is whether it is worthwhile [for the sonic improvements to be had] to remove them, short their pads and solder in caps to the AMS1117 regulators like was done in post 4 or just remove the caps and short their pads for cleaner output?
 

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I have this DAC that combines the SA9023 and ES9023 and it sounds very good for the price. I notice that they have the two 10uf caps [see attached pics] so my question is whether it is worthwhile [for the sonic improvements to be had] to remove them, short their pads and solder in caps to the AMS1117 regulators like was done in post 4 or just remove the caps and short their pads for cleaner output?


Just remove them. I wonder who designed these circuits. It'd be strange to use output caps since these DACs (ES9023 & PCM5102) are mainly advertised for direct output (ground centered, 2Vrms).
 
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Now that the DAC is in a case, thought I would upload a pic. Two ultra low noise external 3.3v feeds bypass the regulators to supply the DAC and USB chips and the output stage has been modified to incorporate a 470R Kiwame resistor and 2N2 Evox Rifa PFR poly prop cap hardwired to new phono sockets as recommended on the PCM5102A datasheet.
 

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Is there anything that could maybe help give it a little stronger low end?
For the cost it's a really nice little DAC (after removing the coupling caps), it just seems to lack a little on the low end compared to the FIIO E10 I used before. (Why am I not using the E10 then? I can't listen to it for prolonged periods, something about its high end always ends up agitating me)

If there are further mods that could be done to this PCM5102 DAC, that would be fun.

I'll likely keep on looking at more DACs anyway, would just be great to make this little one sound even better.

Thanks,

Daniel

And for reference:
https://support.hifimediy.com/suppo...for-savitech-sa9227-9018-9018d-uh1-uh1-digita

Still the latest link, emailed to me by the seller.
It might not hotplug but plays fine after booting up.
 
To improve the low end, the first thing I'd look at is the DAC output impedance and amplifier input impedance. The PCM5102 has a relatively high output impedance (100ohms or more from memory) and there may be additional series resistors on the output (the datasheet recommends 470ohm). If the dac is connected directly to a relatively low input impedance amp (10Kohm or so) that would typically impact dynamics and bass weight/focus. I'd try a buffer stage between the Dac output and amplifier input.
 
Is there anything that could maybe help give it a little stronger low end?
For the cost it's a really nice little DAC (after removing the coupling caps)

You could bypass the low pass filter altogether and wire straight from the + side where the coupling caps were to the phono sockets. This is what John Kenny does in his JKDAC32.

I asked him about this and given the datasheet states "Compared with many conventional switched capacitor DAC architectures, the PCM510xA family offers up to 20 dB lower out-of-band noise, reducing EMI and aliasing in downstream amplifiers/ADCs, measured from the traditional 100-kHz OBN measurements to 3 MHz).", he said "In my research & experiments, this DAC sounded better when used with no RC filter on it's output - the noise is obviously low enough to be of no concern to downstream preamplifiers/amplifiers."

I have also tried various dual 3.3v linear power supply options wired directly to the board where the two AMS1117-3.3v regulators sit. This gives significant improvements, but by far the biggest improvement is achieved by powering these two 3.3v circuits by a regulated battery supply.
 
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