I just want to use a cheap dac (for now) to upgrade sound from a realtek Alc269 hd audio codec of a notebook as it is the main sound source connected to my amp (decent only with EQ).
USB audio performance is critical as I use digital files media mostly (flac/mp3) and CDs over usb.
I would like to ask community, for some additional info about this cheap dac device I have found:
SU0 xmos u8 dac + AK4490 asynchronous usb decoder
example: Finished SU0 XMOS U8 DAC+ AK4490 top asynchronous USB decoder with headphone-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
you can easily find pictures of pcb of this device in the net
1. Has anyone have ever heard or have any opinion on the sound quality of this device?
2. If I use an external USB CD/DVD Drive on a notebook will it be able to reproduce my CDs decently without to much audible jitter/artifacts? As far as I can remember from the past there is a way with some media players to on the fly "extract/rip" a cd and play it through any sound driver (xmos here).
3. What about the one op-amp used in this design (dip-8 socket replaceable)? I am mostly interested in line output (it says 2.5Vrms). Is this one and only op-amp connected to line-output or it only amplifies and affects headphone output? If I will test/use a better alternative (Like LME49720NA/HA) will it affect the line output sound quality (and/or headphone)? (the current one is a JRC 5532D)
4. Can I use a 5v USB battery power bank to power supply this device to upgrade sound quality? I think the cheap included adapter is 8v but it can be powered from usb (not recommented).
5. Other possible cheap improvements?
I am not an electronics expert but I can follow some basic directions.
Thanks
USB audio performance is critical as I use digital files media mostly (flac/mp3) and CDs over usb.
I would like to ask community, for some additional info about this cheap dac device I have found:
SU0 xmos u8 dac + AK4490 asynchronous usb decoder
example: Finished SU0 XMOS U8 DAC+ AK4490 top asynchronous USB decoder with headphone-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
you can easily find pictures of pcb of this device in the net
1. Has anyone have ever heard or have any opinion on the sound quality of this device?
2. If I use an external USB CD/DVD Drive on a notebook will it be able to reproduce my CDs decently without to much audible jitter/artifacts? As far as I can remember from the past there is a way with some media players to on the fly "extract/rip" a cd and play it through any sound driver (xmos here).
3. What about the one op-amp used in this design (dip-8 socket replaceable)? I am mostly interested in line output (it says 2.5Vrms). Is this one and only op-amp connected to line-output or it only amplifies and affects headphone output? If I will test/use a better alternative (Like LME49720NA/HA) will it affect the line output sound quality (and/or headphone)? (the current one is a JRC 5532D)
4. Can I use a 5v USB battery power bank to power supply this device to upgrade sound quality? I think the cheap included adapter is 8v but it can be powered from usb (not recommented).
5. Other possible cheap improvements?
I am not an electronics expert but I can follow some basic directions.
Thanks
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Quick heads up:
I received my DAC yesterday. It sounds pretty good on first listen, although I haven't had the time to compare with anything else.
I opened it up and it is indeed an AK4490EQ with an XMOS USB interface. The solder work is pretty sloppy, but everything seems to work fine. I'll post some pictures of the guts tomorrow if I have the time.
Does anyone have any information on how I might select the active filter on the AK4490?
I received my DAC yesterday. It sounds pretty good on first listen, although I haven't had the time to compare with anything else.
I opened it up and it is indeed an AK4490EQ with an XMOS USB interface. The solder work is pretty sloppy, but everything seems to work fine. I'll post some pictures of the guts tomorrow if I have the time.
Does anyone have any information on how I might select the active filter on the AK4490?
No I haven't purchased it yet but I probably will, i am cheking som other configurations.
But if you need info about filters check this more serious implementation:
http://www.diyaudio.com/forums/vendors-bazaar/274456-ak4490-usb-dac-dsd-support-26.html
I suppose you will need a special driver to do so.
If you test audio quality for this device please let us know your findings.
As far as I can see some sellers give a 8v switching power supply. I guess this is a very basic and noisy power supply. I have some old AC/DC 9V regulated power supplies (heavy, probably linear?) I guess they will do the work better, can anyone confirm this?
What are the specs of this 8v power supply?
I am also wondering how a cheap tube preamp after this dac, could change the sound behaviour. e.g.
6J1 X2 HiFi Stereo Tube Valve Preamp Preamplifier Amplifier | eBay
1pc 6J1 Valve Pre Amp Tube Preamplifier Kit Assembled Board Audio DIY | eBay
Latest 6J1 HiFi Stereo Tube Pre Amp Valve Audio Preamplifier with Power Adapter | eBay
But if you need info about filters check this more serious implementation:
http://www.diyaudio.com/forums/vendors-bazaar/274456-ak4490-usb-dac-dsd-support-26.html
I suppose you will need a special driver to do so.
If you test audio quality for this device please let us know your findings.
As far as I can see some sellers give a 8v switching power supply. I guess this is a very basic and noisy power supply. I have some old AC/DC 9V regulated power supplies (heavy, probably linear?) I guess they will do the work better, can anyone confirm this?
What are the specs of this 8v power supply?
I am also wondering how a cheap tube preamp after this dac, could change the sound behaviour. e.g.
6J1 X2 HiFi Stereo Tube Valve Preamp Preamplifier Amplifier | eBay
1pc 6J1 Valve Pre Amp Tube Preamplifier Kit Assembled Board Audio DIY | eBay
Latest 6J1 HiFi Stereo Tube Pre Amp Valve Audio Preamplifier with Power Adapter | eBay
![IMG_20151103_201952[1].jpg](/community/data/attachments/480/480929-dba41caac00aae79e155b06e70c3f3f8.jpg)
If you mean the digital filters in the AK4490 it looks like they can only be changed in this design by modifying the hardware. As far as I can see, the AK4490 is used in the "Parallel Control Mode" (by setting pin 13 high). In this mode pin 8 and 9 determine the filter setting. They have also been tied to the supply. So they will have to be (carefully) lifted from the PCB and tied either high or low depending on what filter you want to use. See the AK4490 data sheet for details on how to select the filter type.
Yours is definitively well made compared to mine
To be honest, at the first glance I had some doubts about sound because some soldering parts are far from perfect, but overall listening leaves the best impressions. Only power supply disappoints much and has to be replaced.
Do not has the intention to hijack this thread, just showing how the EGD layout done.
but at the price of eur50, it's hard not to pull off the trigger.
Stoner acoustics writes this on its web page:
[FONT=arial, sans-serif]Ever wondered why your DAC sounds different on different devices or even at different places? USB Powered DACs are often powered by switching power supplies from the computers which are non-isolated, thus any dynamic loading from the devices induces unexpected noise into the signal chain. This is the same even if said device is powered by the computer's battery. Additionally, when the power is non-isolated from the transmission signal, the fluctuating relationship between both signal and power causes even more performance degradation. It can be summarized in essence that these inconsistencies are what causes the difference.
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Which is complete bullocks. The signal chain is bloody digital. I wouldn't trust any layout from a company that is so confused on the basics.
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Which is complete bullocks. The signal chain is bloody digital. I wouldn't trust any layout from a company that is so confused on the basics.
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When using a non-isolated DAC(especially the one needed external power), cares needed to take into consideration. You actually able to measure the dirty noise floor when two active devices (with non-isolated PSU), + signal cable are connected together.
In some case, you are not only getting a bad THD and SNR, the side bands is even worst when you run the Jtest too.
This is a loopback test for worst scenarios explanation.
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There surely are some bad ones around since it is more difficult to not make mistakes, but I have not been able to measure or hear any such problems with well executed designs.
The AK4490 cheap DAC is a good example of this. The design works very well and it measures great (in spite of sloppy soldering). Design trumps everything.
The AK4490 cheap DAC is a good example of this. The design works very well and it measures great (in spite of sloppy soldering). Design trumps everything.
The isolation is implemented on Audio DACs to reduce the vulnerability to such circumstances. Active devices will totally not happy in a "electric loop".
1. Put your favorite “reference” album (in my case this is Nick Cave and Bad Seeds “Murder Ballads” and Tori Amos “Under the Pink”
2. Listen in accordance with your previous intrinsic experience
3. Do you care about soldering or something else that distracts your sharp ear from perception of music? If you not satisfied - buy something different.
I have been listening from pioneer, teac, micromega, onkyo cd-players and have to admit that xmos 4490 dac is very close to my musical preferences in terms of further upgrade.
If daс is able to transmit characters and temper, so who cares about soldering and galvanic implementation for 50 euros?
2. Listen in accordance with your previous intrinsic experience
3. Do you care about soldering or something else that distracts your sharp ear from perception of music? If you not satisfied - buy something different.
I have been listening from pioneer, teac, micromega, onkyo cd-players and have to admit that xmos 4490 dac is very close to my musical preferences in terms of further upgrade.
If daс is able to transmit characters and temper, so who cares about soldering and galvanic implementation for 50 euros?
calm down. The isolation explanation is to address out what vacuphile questioning on the previous post.- Status
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