Hi all,
I bought one of this toy from EBay a week ago and I received the parcel in couple of days. It came with a +12Vdc power adapter. After listening to it for a day, I started the modifications to it that I hope to get better sound out from it.
I modified the DAC to work with a Power-One HAA15 stabilized power supply supply module. The PS module was set up to provide +/- 10Vdc for the DAC.
Also, I replaced 4 pcs of 1000uF 25V capacitor for the +/-VCC bypass with Blackgate 2000uF 16V one.
I had it hooked up to the Denon CD player to the SPDIF input. It sounds pretty good but lack the brightness in the treble and highs. I set up my PC to link to the DAC through the USB. It sounds much better and the treble/highs were clear and sharp - that's what I want.
That make me wonder how I could further improve the sound quality with SPDIF input??? Any ideas how to do it?
Best regards,
Johnny Tang
Vancouver, BC, Canada
I bought one of this toy from EBay a week ago and I received the parcel in couple of days. It came with a +12Vdc power adapter. After listening to it for a day, I started the modifications to it that I hope to get better sound out from it.
I modified the DAC to work with a Power-One HAA15 stabilized power supply supply module. The PS module was set up to provide +/- 10Vdc for the DAC.
Also, I replaced 4 pcs of 1000uF 25V capacitor for the +/-VCC bypass with Blackgate 2000uF 16V one.
I had it hooked up to the Denon CD player to the SPDIF input. It sounds pretty good but lack the brightness in the treble and highs. I set up my PC to link to the DAC through the USB. It sounds much better and the treble/highs were clear and sharp - that's what I want.
That make me wonder how I could further improve the sound quality with SPDIF input??? Any ideas how to do it?
Best regards,
Johnny Tang
Vancouver, BC, Canada
After reviewing the schematic for sometime, I decided to modify this DAC to remove the transistors from the headphone amp and strapped the Op-Amp as 1:1 buffer. Then, remove the input coupling capacitors and take to buffer output to the RCA jack.
This would provide better buffering from the DAC to the line amplifier. Also, I could use the volume and the DAC can be connected directly to any power amplifiers.
After this mod, the sound from the CD players sound more brighter that I would expect.
Now I can enjoy my CD collections all over again.
I am wondering how to squeeze more juice from this DAC, any ideas??
Johnny Tang
This would provide better buffering from the DAC to the line amplifier. Also, I could use the volume and the DAC can be connected directly to any power amplifiers.
After this mod, the sound from the CD players sound more brighter that I would expect.
Now I can enjoy my CD collections all over again.
I am wondering how to squeeze more juice from this DAC, any ideas??
Johnny Tang
DIR9001 XTI must be connected to DGND
As per DIR9001 datasheet - when it is not using external clock source, the XTI pin of the DIR9001 must be connected to the DGND. I had the DAC opened up and soldered a small piece jumper wire to connect the DIR9001 XTI input pin 8 to the DGND for a trial because I found the sound from the CD SPDIF source wasn't quite right, kind of too mellow.
After this fix, the sound from the CD - SPDIF source became much for solid and dynamic. It is quite similar to the character from the USB source. I was very surprised with this change.
I can't say this is a design fraud but I firmly believe this should be the right kind of sound it should be. I hope someone could try it and see whether they like this change.
Comments are very welcome.
JOhnny
As per DIR9001 datasheet - when it is not using external clock source, the XTI pin of the DIR9001 must be connected to the DGND. I had the DAC opened up and soldered a small piece jumper wire to connect the DIR9001 XTI input pin 8 to the DGND for a trial because I found the sound from the CD SPDIF source wasn't quite right, kind of too mellow.
After this fix, the sound from the CD - SPDIF source became much for solid and dynamic. It is quite similar to the character from the USB source. I was very surprised with this change.
I can't say this is a design fraud but I firmly believe this should be the right kind of sound it should be. I hope someone could try it and see whether they like this change.
Comments are very welcome.
JOhnny
Good buy!!!!!!!!!!
I brought this little DAC to my friend's home on Saturday. He is having Linn amplifier system with Sonic Frontier DAC.
Thanks for the latest DA technology, the AUNE has much better definition, dynamic and crystal clear. We could hear those small small sound details that we never heard before.
Good buy for AUNE but I need to explore for better one from now..
Johnny
I brought this little DAC to my friend's home on Saturday. He is having Linn amplifier system with Sonic Frontier DAC.
Thanks for the latest DA technology, the AUNE has much better definition, dynamic and crystal clear. We could hear those small small sound details that we never heard before.
Good buy for AUNE but I need to explore for better one from now..
Johnny
recap with elna rsf
burson regulator
burson clock w/±1ppm tcxo
burson opamp
sounds great. transformed.
next up are the 3 voltage regulators.
burson regulator
burson clock w/±1ppm tcxo
burson opamp
sounds great. transformed.
next up are the 3 voltage regulators.
An externally hosted image should be here but it was not working when we last tested it.
Hello gwillys,
Please note that the max input voltage of the LT1117 voltage regulator is 15Vdc only. Check the datasheet to make sure before you increase the +/-10V to +/-18V. I think you may use one more regulator to lower the +18V to 10V before feeding to the 5 and 3.3V regulators.
Johnny
Please note that the max input voltage of the LT1117 voltage regulator is 15Vdc only. Check the datasheet to make sure before you increase the +/-10V to +/-18V. I think you may use one more regulator to lower the +18V to 10V before feeding to the 5 and 3.3V regulators.
Johnny
Hi gwillys,
One more questions, it seems you put the burson oscillator to the PCM2707 USB interface chip. What about the DIR9001? Did you add the TXCO to it? If not, I would recommend you to ground the XTI pin of the chip, it improves the sound significantly.
Johnny
One more questions, it seems you put the burson oscillator to the PCM2707 USB interface chip. What about the DIR9001? Did you add the TXCO to it? If not, I would recommend you to ground the XTI pin of the chip, it improves the sound significantly.
Johnny
hi johnny.
all you need to do is check input voltage on the 3 regulators. you will see it is good.
maximum 24v psu though.
your over my head re: clock. maybe you could explain further. are you saying the DIR9001 doesn't use the clock?
all you need to do is check input voltage on the 3 regulators. you will see it is good.
maximum 24v psu though.
your over my head re: clock. maybe you could explain further. are you saying the DIR9001 doesn't use the clock?
maybe this is it? interesting. i have a 24.576mhz clock here. don't know how to implement it at this point.
Yes, you can add the 24.576MHz clock to the XTI input or simply ground it. It should be more stable with external clock.
The DIR9001 is used for the CD SPDIF RCA input. I don't have the external clock. Therefore, I need to have this pin ground as per the manufacturer's datasheet.
Johnny
The DIR9001 is used for the CD SPDIF RCA input. I don't have the external clock. Therefore, I need to have this pin ground as per the manufacturer's datasheet.
Johnny
An externally hosted image should be here but it was not working when we last tested it.
[/QUOTE]This kit is come from China.
@ johnny: maybe you'll find this interesting.
DSIX SPDIF Digital Signal Isolation Exciter for DAC - eBay (item 290458498434 end time Aug-26-10 17:01:47 PDT)
DSIX SPDIF Digital Signal Isolation Exciter for DAC - eBay (item 290458498434 end time Aug-26-10 17:01:47 PDT)
Sounds very interesting indeed.
I just have too many project running and I may try it later.
Johnny
I just have too many project running and I may try it later.
Johnny
hi Johnny & Gwillys,
I found my Aune's sound is very controlled, and I prefer to have more extension - eg. higher high, and lower low. May you suggest if simply rolling op-amp will improve it? or what to do to improve this? Thx much!
I found my Aune's sound is very controlled, and I prefer to have more extension - eg. higher high, and lower low. May you suggest if simply rolling op-amp will improve it? or what to do to improve this? Thx much!
Hello SlowPork,
I really don't think it would sound differently by changing the op-amp chips. I think you may try to modify the power suppy to an external +/-10~12Vdc and connect it directly to the DAC, bypassing the chip. I don't know if you can get the upgrade power supply kit from them. Also, you can add a 0.1uF film capacitor to bypass the +/- 12Vdc rails that would give you even smoother highs.
After listening to this Aune DAC for sometime, I found the sound from the SPDIF input is rather different from the USB. I use a PC and CD player to play the same CD. The PC linked with USB interface and CD to the SPDIF. It sound very different. The sound through SPDIF interface is extremely detailed, deep sound stage and well controlled. The sound from the USB port is a bit loose and puffy.
What could be different? The USB is through the PCM2707 and SPDIF is through the DIR9001 digital audio receiver. Surely DIR9001 has very low jittering rate than the PCM2707.
I am lost totally and wonder what good sound should be.
Johnny
I really don't think it would sound differently by changing the op-amp chips. I think you may try to modify the power suppy to an external +/-10~12Vdc and connect it directly to the DAC, bypassing the chip. I don't know if you can get the upgrade power supply kit from them. Also, you can add a 0.1uF film capacitor to bypass the +/- 12Vdc rails that would give you even smoother highs.
After listening to this Aune DAC for sometime, I found the sound from the SPDIF input is rather different from the USB. I use a PC and CD player to play the same CD. The PC linked with USB interface and CD to the SPDIF. It sound very different. The sound through SPDIF interface is extremely detailed, deep sound stage and well controlled. The sound from the USB port is a bit loose and puffy.
What could be different? The USB is through the PCM2707 and SPDIF is through the DIR9001 digital audio receiver. Surely DIR9001 has very low jittering rate than the PCM2707.
I am lost totally and wonder what good sound should be.
Johnny
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as far as the initial sound, it should improve somewhat after 50/100 hrs burn in.
the changes i've made make a big difference. i only use rca out, and currently no opa's on board. extended, very nice sound on my setup. as johnny said, power supply is all important with these things. the burson regulator @ 17/18v output is great. i have a mundorf mlytic 4700uf at the input of the burson regulator.
lots of mods can be done. i highly recommend a recap with elna rsf, but psu is most important, and you wont get best power off just a wallwart.
+/-1PPM 12mhz TCXO/burson clock/regulator for PCM2707 & 24.576 for DIR9001. from my experiance, i can tell you there is no substitute for swapping out the very cheap components they use on these boards. 1117 & 7808 regulators have to go to 🙂
the most sensible thing to do is just buy a better dac, but i enjoy modding.
hi slowpork,
while it won't fix everything, i would recommend trying a different opamp in the DAC and/or HP amp. if i remember correctly, there is an OPA2604 in there which is not considered a very neutral chip - warm, fuzzy and lacking extension seem to be the common complaints. OPA2134 isn't always the best choice either, though i have heard some circuits sound good with it.
i have a knock-off version of the Aune Mk.I called the Muse, it is mostly identical in topology if not component quality. i just tried a bunch of opamps - AD827, OPA2107, OPA1642, AD825 - and i think they could potentially sound better than the stock chips. i wrote about it on head-fi:
Muse Audio DAC? - Page 6 - Head-Fi.org Community
just be sure to use an FET-input opamp for the HP amp or you will have DC offset issues (e.g. don't use AD827).
cheers,
dorkus
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