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AK4490 USB Dac with dsd support.

Hello all.

My brother and i have made an commercial USB DAC module called Phison Audio DAC V1.1.

We have made an scaled down version of this DAC for DIY and for OEM use.

What this DAC provide you with is USB AUC 2, so for OS/X and Linux units there is not need for drivers. For Windows we provide an driver.

The USB interface can later be updated which you properly will ;)

As a basic unit the USB DAC is self contained, and does only need +5.5V,+15V and -15V from a supply of your own choice, but it works very well with an SMPS as there is heavy use of High performance LDO regulators on the board.

A feature list:
  • USB AUC 2
  • PCM up to 384KHz/32Bit
  • DSD/DOP 64,128 and 256 (First software revision does not have DSD 256)
  • AKM AK4490 DAC in stereo configuration
  • Output stage mounted on a "shield" to make it possible for users to make there own output stage, but we provide an standard shield with the USB DAC.
  • Output stage i standard single ended with ADA4627-1 opamp from AD
  • 9 high performance voltage regulators
  • AK4490 VREF bypassed with 1500uF Polymer capacitors
  • 10 pole ribbon cable connector for frontpanel (Planned upgrade)
  • 10 pole ribbon cable connector for preamp section (Planned upgrade)
  • Power is through an Molex KK grid 2.54mm connector. We provide an cable harness with the kit.
  • Board size is 70x110mm, 4 layer PCB

This board costs :

216€ + shipping in early bird

236€ + shipping after 1. june 2015

For OEM prices please contact us at mail(at)mirand-audio.dk

Together with the planed upgrade of an "front panel" and "preamp" we will also make an "output shield" for "balanced signal".


DAC pre-order is as following:
stajo = 1
pinnocchio = 1
Press57 = 1
Myint67 = 1
rogerchou = 1

Best regards Sonny
 
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The USB DAC will start ship out from monday 1. june 2015

Pictures of the USB DAC main board:
 

Attachments

  • MIRAND USB DAC V10.jpg
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fab

Member
Paid Member
2004-03-24 1:16 am
Canada
fabaudio.online
Very interesting product...

Good idea the use of polymer caps for VREF.
I like a lot the bass restitution of the AK4490.

Some questions:
Are the 5 possible digital filters selectable and how (hardware jumpers, software, ...)?
Is the analog voltage value optimized for maximum dynamic range?
For your optional output stage, what is the order of the filter used and the Fc?

Thanks
Fab
 
Very interesting product...

Good idea the use of polymer caps for VREF.
I like a lot the bass restitution of the AK4490.

Some questions:
Are the 5 possible digital filters selectable and how (hardware jumpers, software, ...)?
Is the analog voltage value optimized for maximum dynamic range?
For your optional output stage, what is the order of the filter used and the Fc?

Thanks
Fab

It will be possible to change the filter with the front panel added. But in this firmware version it is locked. But i can provide 5 firmware versions to choose from.
The analog voltage is set for 5V. Partly because of the capacitors which is 6.3V and have an ESR of only 8mOhm.

The filter is in this version set to DSD (-3dB ~50KHz), but there is an DSD/PCM pin in the output stage connector for changing the filter in later editions of the outputstage.
 

pdb

Member
2007-02-06 11:18 am
Bornholm
....it works very well with an SMPS as there is heavy use of High performance LDO regulators on the board...
Sonny, is XP Power ECL15UT03-T the psu you are using in your test setup? What about a pre-order list for this (or another) DC supply? Just an idea. Per

[IMGDEAD]http://uk.farnell.com/productimages/standard/en_GB/1289138-40.jpg[/IMGDEAD]
 
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It will be possible to change the filter with the front panel added. But in this firmware version it is locked. But i can provide 5 firmware versions to choose from.
The analog voltage is set for 5V. Partly because of the capacitors which is 6.3V and have an ESR of only 8mOhm.

The filter is in this version set to DSD (-3dB ~50KHz), but there is an DSD/PCM pin in the output stage connector for changing the filter in later editions of the outputstage.

I was a bit to fast yesterday evening. I checked my schematic and i have actually set the voltage to 6.1V just below recommended maximum voltage of the Capacitor.

BR Sonny
 

pdb

Member
2007-02-06 11:18 am
Bornholm
I am preparing a powersupply kit.

Is a c8 (shaver) power inlet fine?

I will contact hifi2000 In italy to get them providing a chassis with all holes needed for diyaudio.
Sounds great Sonnya :) Will cabinet be available in black? Regarding power inlet I guess most diy'ers would prefer an IEC 320 C14 inlet (first pic). Maybe even with an option for a nice quality integrated line filter (second pic) with or without a fuseholder / powerswitch? The C14 / standard socket would make it more straightforward using an aftermarket or diy powercord and give the possibility for safety earch / ground. (Third pic shows C8 standard socket for comparison). Per PS: For the best standard I personally would go for the Neutric Powercon (blue connector) but that is a another story... :)

[IMGDEAD]https://www.alliedelec.com/images/products/Small/70080701.jpg[/IMGDEAD][IMGDEAD]https://www.alliedelec.com/images/products/Small/70080708.jpg[/IMGDEAD][IMGDEAD]https://media.digikey.com/photos/Schurter%20Photos/4300.0096_sml.jpg[/IMGDEAD][IMGDEAD]https://www.neutrik.com/website/uploads/images/06/140x140/nac3mpa-1.jpg?v=1[/IMGDEAD]
 
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Heard that AK4490 works optimally on 7V instead of 5.5V.

Hello rredline.

I runs at 6.1V just below the voltage of the PCK0J152MCO1GS we use for bypass of VREF rails. They are polymer types with 8mOhm ESR value and keeps it very low (<20mOhm) to a few MHz. The capacitor we have choosen for VREF is also 1500uF.

So for sure you can gain better S/N ratio, but we get a better capacitor by reducing it to 6.1V instead. Also with 1500uF we improve it in the low range.

vrefcap.png


So what do you want? gain 1 - 2dB better S/N ratio or having better overall results?

BR Sonny