Melodious MX-U8 USB Interface 8 Core XMOS chip

[abartels]

Normally i would agree, but my mxu8 only works stable at lowest settings in combination with jplay, strange but true, ,,

 

[rb2013]

Normally i would agree, but my mxu8 only works stable at lowest settings in combination with jplay, strange but true, ,,

I had the opposite effect - but JPlay did help with all the DDCs including the Hydra Z to sound better.  Which does make sense since it's shutting down the other operations and giving priority to the audio player.
 
The Hydra Z had very occasional 'hiccups' - not pops or clicks before I turned on Jplay 6.  After they were completely gone.  SQ improved.
 
Here is the I2S version of the DIYinHK board with the NDKs
http://www.diyinhk.com/shop/audio-kits/58-xmos-dsd-dxd-384khz-high-quality-usb-to-i2s-pcb.html
with LED board
http://www.diyinhk.com/shop/audio-kits/58-xmos-dsd-dxd-384khz-high-quality-usb-to-i2s-pcb.html#/xmos_option-xmos_and_led_pcb
 
$65.95 with LED!  It doesn't come with the box as plug and play unit like the SPDIF DXIO Pro3 version - but that would be easy enough to make.  It also runs off the 3.3V DAC power line or would need a seperate regulated power board.

 
 

XMOS DSD DXD 384kHz high-quality USB to I2S/DSD PCB (includes 2.54mm spacing 10x2row 30u gold plated header pins)
This is the best USB to I2S/DSD PCB for audiophile Diyer to enjoy.
Feature:
1) Newest XMOS chip and uses 48MHz oscillator to asynchronous reclock usb audio data to I2S line, old XMOS uses only 13Mhz oscillator, over 4x better jitter rejection theoretically.
2) Solid ground plane (a must for high speed digital circuit)
3) No Via in active circuit (via inductance always create jitter problem)
4) NDK NZ2520SD Ultra low phase noise oscillator and Murata capacitor sourced from Japan directly (guarantee no fake product from China)
According to the official datasheet, the phase noise of NZ2520SD is much better than the famous crystek 957 under 25khz(human listenable range)
For easier comparsion(lower is better), we overlay the two phase noise graph at the same scale, under 25khz(human listenable range) nz2520sd(red line) is better, over 25khz(human unlistenable range) crystek 957 is better.
5) Gold plated USB connector (Molex, FCI, or other depends on stock)
6) Compact size 50mm x 30mm
7) PCB uses external 3.3V(>150mA) regulated power supply, it is usually connected to the same 3.3v digital power DAC is using(warning: over-voltage or reverse-voltage can damage the xmos chip immediately, double check before power on)
8) Extreme diyer can cut and install series resistor in the pre-allocated 0805 footprint space in the I2S line to match their DAC line impedance
No drivers needed for MAC OS version 10.6.4  and above
No drivers installation required for Linux with UAC2 compliant kernel
ASIO/KS/WASAPI/Direct Sound drivers for Windows XP to 8 (32 and 64 bit)
Fully featured Thesycon driver package (without 30 min. periodic beeps)
Windows 7/8/Vista/XP Driver is available to download from our website
http://www.diyinhk.com/shop/9-driverdatasheetmanual
*USB2.0 is a must for 384kHz operation
*Use a fresh install of windows and a dedicated USB port always avoid problem and run stable
*The length of I2S connection to your DAC chip should be as short as possible for best result and below 10cm is recommended
Please check your DAC should support the following I2S signal specification to decode each sampling rate:

DATA	LRCK	BCLK	MCLK
16/24bit	44.1kHz	2.8224Mhz	22.5792Mhz
16/24bit	48kHz	3.072Mhz	24.576Mhz
16/24bit	88.2kHz	5.6448Mhz	22.5792Mhz
16/24bit	96kHz	6.144Mhz	24.576Mhz
16/24bit	176.4kHz	11.2896Mhz	22.5792Mhz
16/24bit	192kHz	12.288Mhz	24.576Mhz
16/24bit	352.8kHz	22.5792Mhz	22.5792Mhz
16/24bit	384kHz	24.576Mhz	24.576Mhz

Just to correct as DIYinHK keeps repeating the same misinformation on the NDK vs Crystek clock comparison.
 
THE NDK outperforms under 2,500Hz NOT 25,000Hz -they're misreading their own log chart! Still the NDK's are a bargain at the price.  Note the phase noise of the CCHD957 (blue line) is better then even the OXCO (green line) (and the NDK SD - red line) from 2.5kHz to 1mHz!

 

[rb2013]

Here is the link to the data sheet for the CCHD 957 at different clock frequencies available.  The one in the DIYinHK is for the 22.5792MHz clock.
http://www.crystek.com/crystal/spec-sheets/clock/CCHD-957.pdf
 
The other clock frequencies at 10Hz are:
24.5762  -97.95
45.1584 -100.07
49.152 -98.48
 
The 22.5792 they use as an overlay in the chart is the worst performing at 10hz at -97.38

 

[abartels]

Hi Bob,
 
Not to be picky, but I posted the isolated version several times in this thread or the U12 thread, thought you would have noticed at least 

 
 
http://www.diyinhk.com/shop/audio-kits/69-isolated-xmos-dsd-dxd-384khz-high-quality-usb-to-i2sdsd-pcb-with-ultralow-noise-regulator.html
 
It's completely isolated, can feed it with seperate powerlines, it's the best deal ever.
I am planning to use this one when deciding which dac I'm gonna build.
 
Pricing: USD 89,95  It's a steal!
 

 
Isolated XMOS DSD DXD 384kHz high-quality USB to I2S/DSD PCB with ultralow noise 6.5uV regulator and sampling rate LED indicator PCB(all smd are soldered, thru hole component are not soldered)

This is the best USB to Isolated I2S/DSD PCB for audiophile Diyer to enjoy, with the audio oscilaltor on the clean isolated side, it take the performance to the other world.

Features:

1) Newest XMOS chip and uses 48MHz oscillator to asynchronous reclock usb audio data to I2S line, old XMOS uses only 13Mhz oscillator, over 4x better jitter rejection theoretically.

2) Audio oscillators 22.5792Mhz and 24.576Mhz are located on the clean isolated side for highest performance.

3) 6.5uVrms Ultralow noise linear power regulator (use of decade old LM317/1117 regulator is kidding for audiophile)

4) Solid ground plane (a must for high speed digital circuit)

5) No Via in active circuit (via inductance always create jitter problem)

6) NDK NZ2520SD Ultralow phase noise oscillator are sourced from Japan directly (guarantee no fake product from China)
According to the official datasheet, the phase noise is much better than the famous crystek 957 under 25khz(human listenable range)
For easier comparsion(lower is better), we overlay the two phase noise graph at the same scale, under 25khz(human listenable range) nz2520sd(red line) is better, over 25khz(human unlistenable range) crystek 957 is better.

7) Gold plated USB connector (Molex, FCI, or other depends on stock)

8) Compact size 60mm x 40mm

No drivers needed for MAC OS version 10.6.4  and above
No drivers installation required for Linux with UAC2 compliant kernel
ASIO/KS/WASAPI/Direct Sound drivers for Windows XP to 8 (32 and 64 bit)
Fully featured Thesycon driver package (without 30 min. periodic beeps)

Windows 7/8/Vista/XP Driver is available to download from our website
http://www.diyinhk.com/shop/9-driverdatasheetmanual

*USB2.0 is a must for 384kHz operation
*Use a fresh install of windows and a dedicated USB port always avoid problem and run stable
*The length of I2S connection to your DAC chip should be as short as possible for best result and below 10cm is recommended

Please check your DAC should support the following I2S signal specification to decode each sampling rate:

DATA	LRCK	BCLK	MCLK
16/24bit	44.1kHz	2.8224Mhz	22.5792Mhz
16/24bit	48kHz	3.072Mhz	24.576Mhz
16/24bit	88.2kHz	5.6448Mhz	22.5792Mhz
16/24bit	96kHz	6.144Mhz	24.576Mhz
16/24bit	176.4kHz	11.2896Mhz	22.5792Mhz
16/24bit	192kHz	12.288Mhz	24.576Mhz
16/24bit	352.8kHz	22.5792Mhz	22.5792Mhz
16/24bit	384kHz	24.576Mhz	24.576Mhz

 

 DSD playback steps using foobar2000 in Microsoft Windows:

1. Download and install the latest version of Foobar2000 from the official website

http://www.foobar2000.org/download

2. Download and install the official ASIO output plug-in for Foobar2000

http://www.foobar2000.org/components/view/foo_out_asio

3. Download the latest version of Super Audio CD Decoder plug-in for Foobar2000

http://sourceforge.net/projects/sacddecoder/files/foo_input_sacd/

3a) unzip and double click to install ASIOProxyInstall-x.x.x.x.exe

3b) Foobar > Files > Perferences > Components > Install > foo_input_sacd.fb2k-component

4. Configure the output device: Foobar > Files > Perferences > Playback > Output > Device (ASIO: foo_dsd_asio)

5. Configure the ASIO output: Foobar > Files > Perferences > Playback > Output > ASIO > foo_dsd_asio(double click)

5a) ASIO Driver: DIYINHK DXIO USB Audio

5b) DSD Playback Method: DoP Marker 0x05/0xFA

6. Foobar > Files > Perferences > Tools > SACD > ASIO Driver Mode: DSD

More detail: http://www.google.com/search?q=foobar+dsd

User guide:

1) If you do not play DSD from the computer, the PCB will not output DSD signal. It's the same as our old PCB without DSD

2) The isolated clean side uses external 3.3V(>50mA) regulated power supply(20pisn header labelled 3.3vINx2 and GND), it is usually connected to the same 3.3v digital power DAC is using(warning: over-voltage or reverse-voltage can damage the xmos chip immediately, double check before power on)

3) For DSD playback, LRCK= DSD D1(Left channel), DATA= DSD D2(right channel), BCK = DSD Bit Clock

4) Pins labeled (SDA SCL RST MUTE) on CN1 are reserved for used with DAC firmware customization(i.e. software control different DAC with different firmware), it should be left unconnect. CN1 Pin labelled DSDon is isolated, it is high when playing DSD and low when playing PCM.

5) For DSD playback, windows volume mixer must be set to full volume.

6) Different DAC chip needs different software command to switch between DSD and PCM mode. Please read the corresponding DAC datasheet for detail.

 

 

 

Regards,

 

Alex

 

[rb2013]

  Hi Bob,
 
Not to be picky, but I posted the isolated version several times in this thread or the U12 thread, thought you would have noticed at least 

 
 
http://www.diyinhk.com/shop/audio-kits/69-isolated-xmos-dsd-dxd-384khz-high-quality-usb-to-i2sdsd-pcb-with-ultralow-noise-regulator.html
 
It's completely isolated, can feed it with seperate powerlines, it's the best deal ever.
I am planning to use this one when deciding which dac I'm gonna build.
 
Pricing: USD 89,95  It's a steal!
 

 
Isolated XMOS DSD DXD 384kHz high-quality USB to I2S/DSD PCB with ultralow noise 6.5uV regulator and sampling rate LED indicator PCB(all smd are soldered, thru hole component are not soldered)

This is the best USB to Isolated I2S/DSD PCB for audiophile Diyer to enjoy, with the audio oscilaltor on the clean isolated side, it take the performance to the other world.

Features:

1) Newest XMOS chip and uses 48MHz oscillator to asynchronous reclock usb audio data to I2S line, old XMOS uses only 13Mhz oscillator, over 4x better jitter rejection theoretically.

2) Audio oscillators 22.5792Mhz and 24.576Mhz are located on the clean isolated side for highest performance.

3) 6.5uVrms Ultralow noise linear power regulator (use of decade old LM317/1117 regulator is kidding for audiophile)

4) Solid ground plane (a must for high speed digital circuit)

5) No Via in active circuit (via inductance always create jitter problem)

6) NDK NZ2520SD Ultralow phase noise oscillator are sourced from Japan directly (guarantee no fake product from China)
According to the official datasheet, the phase noise is much better than the famous crystek 957 under 25khz(human listenable range)
For easier comparsion(lower is better), we overlay the two phase noise graph at the same scale, under 25khz(human listenable range) nz2520sd(red line) is better, over 25khz(human unlistenable range) crystek 957 is better.

7) Gold plated USB connector (Molex, FCI, or other depends on stock)

8) Compact size 60mm x 40mm

No drivers needed for MAC OS version 10.6.4  and above
No drivers installation required for Linux with UAC2 compliant kernel
ASIO/KS/WASAPI/Direct Sound drivers for Windows XP to 8 (32 and 64 bit)
Fully featured Thesycon driver package (without 30 min. periodic beeps)

Windows 7/8/Vista/XP Driver is available to download from our website
http://www.diyinhk.com/shop/9-driverdatasheetmanual

*USB2.0 is a must for 384kHz operation
*Use a fresh install of windows and a dedicated USB port always avoid problem and run stable
*The length of I2S connection to your DAC chip should be as short as possible for best result and below 10cm is recommended

Please check your DAC should support the following I2S signal specification to decode each sampling rate:

DATA	LRCK	BCLK	MCLK
16/24bit	44.1kHz	2.8224Mhz	22.5792Mhz
16/24bit	48kHz	3.072Mhz	24.576Mhz
16/24bit	88.2kHz	5.6448Mhz	22.5792Mhz
16/24bit	96kHz	6.144Mhz	24.576Mhz
16/24bit	176.4kHz	11.2896Mhz	22.5792Mhz
16/24bit	192kHz	12.288Mhz	24.576Mhz
16/24bit	352.8kHz	22.5792Mhz	22.5792Mhz
16/24bit	384kHz	24.576Mhz	24.576Mhz

 

 DSD playback steps using foobar2000 in Microsoft Windows:

1. Download and install the latest version of Foobar2000 from the official website

http://www.foobar2000.org/download

2. Download and install the official ASIO output plug-in for Foobar2000

http://www.foobar2000.org/components/view/foo_out_asio

3. Download the latest version of Super Audio CD Decoder plug-in for Foobar2000

http://sourceforge.net/projects/sacddecoder/files/foo_input_sacd/

3a) unzip and double click to install ASIOProxyInstall-x.x.x.x.exe

3b) Foobar > Files > Perferences > Components > Install > foo_input_sacd.fb2k-component

4. Configure the output device: Foobar > Files > Perferences > Playback > Output > Device (ASIO: foo_dsd_asio)

5. Configure the ASIO output: Foobar > Files > Perferences > Playback > Output > ASIO > foo_dsd_asio(double click)

5a) ASIO Driver: DIYINHK DXIO USB Audio

5b) DSD Playback Method: DoP Marker 0x05/0xFA

6. Foobar > Files > Perferences > Tools > SACD > ASIO Driver Mode: DSD

More detail: http://www.google.com/search?q=foobar+dsd

User guide:

1) If you do not play DSD from the computer, the PCB will not output DSD signal. It's the same as our old PCB without DSD

2) The isolated clean side uses external 3.3V(>50mA) regulated power supply(20pisn header labelled 3.3vINx2 and GND), it is usually connected to the same 3.3v digital power DAC is using(warning: over-voltage or reverse-voltage can damage the xmos chip immediately, double check before power on)

3) For DSD playback, LRCK= DSD D1(Left channel), DATA= DSD D2(right channel), BCK = DSD Bit Clock

4) Pins labeled (SDA SCL RST MUTE) on CN1 are reserved for used with DAC firmware customization(i.e. software control different DAC with different firmware), it should be left unconnect. CN1 Pin labelled DSDon is isolated, it is high when playing DSD and low when playing PCM.

5) For DSD playback, windows volume mixer must be set to full volume.

6) Different DAC chip needs different software command to switch between DSD and PCM mode. Please read the corresponding DAC datasheet for detail.

 

 

 

Regards,

 

Alex

Sorry missed that as I'm not an I2S guy - so this board is different with regulation on the PS lines.  What a steal for $89!  If you run I2S - why not build one as a stand alone unit?  Could be better than all the other low cost DDCs we've been buying.  Total cost could be competitive.
 
PS Do you have the link to that one.  They have the other DXIO XMOS I2S in stock. 

 

[abartels]

I bought a cheap AK4495SEQ based dac (I2S ONLY) to test with, curious what AK449x chips can do,
if I like it I'm going to buy the complete diyinhk set and build it extensively with lots of R-Cores en lots of 0.8uV ultra low noise psu's.
 
http://www.diyinhk.com/shop/audio-kits/68-768khz32bit-ak4490eq-dac-i2sdsd-input.html#/dac_option-isolated_xmos_dac_and_led_pcb
 
Pricing: USD 149,95
 
There's an extended article on HifiDuino how to feed this DAC with seperated psu's for all stages, including left and right seperated.
It's also possible to buy 2 DAC's and set them in MONO mode, but pcb has to be modified for that.
 

AK4490EQ is a new generation Premium 32-bit 2ch DAC with new technologies, achieving industry’s leading level low distortion characteristics and wide dynamic range. The AK4490 integrates a newly developed switched capacitor filter “OSR Doubler”, making it capable of supporting wide range signals and achieving low out-of-band noise while realizing low power consumption. Moreover, the AK4490 has five types of 32-bit digital filters, realizing simple and flexible sound tuning in wide range of applications. The AK4490 accepts up to 768kHz PCM data and 11.2MHz DSD data.

This item includes PCB with all SMT component soldered, thru-hole component are not soldered.

*The XMOS PCB in the kit is flashed with our AK4490/4495 customized bit perfect volume control firmware, it send software command and switch AK4490/4495 between DSD and PCM playback. We are the first (since last year 2014) and still the only one (as of today 2015) in the major market can achieve DSD volume control from the PC os mixer bit perfectly. We are proud to ahead of the major market for at less one year. Please notes AK4490/4495 can only playback PCM when running in the default non software control mode.

Features:

1) 768KHz/32Bit AK4490 DAC Chip (industry’s leading level low distortion characteristics and wide dynamic range.)

2) Solid ground plane with careful split of digital and analog portion(a must for highest fidelity audio)

3) No Via in active circuit (via inductance always create jitter problem)

4) 0.1% Low noise thin film resistor and C0G Capacitor sourced from Digikey USA (guarantee no fake product from China)

5) 2200uF panasonc Low ESR capacitor at VREFH/L pin for super bass response and highest performance at 20Hz range frequency.

6) Gold plate I2S input connector and four GND return path dedicated for each I2S signal(lowest contact resistance and highest signal quality)

User guide:

1)The AK4490 PCB can work immediately with only I2S signal and power supply connected, one 3.3V (>300mA), one 5.0V (>100mA) and one +-12V (>100mA) regulated power supply in the default parallel operation mode.

2)For Diyer requires more deeper customization or switch to DSD playback(software I2C command is needed), the latest veraion of AK4490 datasheet is available in the official AKM website.

3)The PCB is designed to be DIY friendly. Diyer can cut the trace and uses the socket labelled AVDD_R(3.3V), DVDD(3.3V) for individual power supply to the Left and right analog power supply and digial supply.

4)The differential output directly from the DAC has labelled with preallocated 2.54mm spacing socket for diyer easily connecting to their favorite IV and LPF and bypass the default onboard one.

5) All dual opamp in single dip8 package IC can be used for this PCB output stage, such as OPA2134 AD8620 etc. One free opamp is included in the package and the model depends on stock.

6) Compact size 60mm x 60mm

Additional user guide when used with XMOS PCB flashed with our AK4490/4495 customized bit perfect volume control firmware:

1) Install jumper on AK4490 PCB PSN socket and SET it to LOW. The DAC will start to run in software control mode.

2) With our customized firmware, the audio data send to the DAC is always bit perfect and the volume control is done in the DAC chip. DSD volume control is available using the operating system mixer.

Without DAC specified firmware, the OS mixer will ruin the audio data if the volume is not set to full and DSD can only be playback at full volume.

Please notes the maxiumum sampling rate is limited by the XMOS PCB and it is 384k.

For advance user only when AK4490 is used with isolated XMOS PCB:

1) To avoid click noise occurs during replug of USB cable, remove FB1 and uses external 5v supply to CN3. Please notes reversed polarity or over voltage can damage the xmos chip immediately.

Specification:

1) I2S Input (MCLK, LRCK, BCK, DATA, GND)

2) Output level: 2V RMS

3) Resolution/Sampling Rate: Up to 32bit/768KHz

4) Supply: Regulated 3.3V, 5V, +-12V

*According to the AK4490 official datasheet page 44 notes 6 and our test, click noise occurs during power on/off, external mute circuit may be needed if click noise adversely affect system performance.

*Our latest D1X headphone amplifier includes power on delay and instant off output relay. It can mute the power on/off click noise of AK4495/AK4490 as well as all the other DAC chip requires this feature.

*For normal user, the newer AK4490 should be a better choice than AK4495. It can support upto 11.2Mhz DSD and it has better THD+N. AK4495SEQ is the first 768k DAC chip from AKM and it can be used as a reference for advanced user.

 

 

NOTE: Picture is wrong picture, it's with non-isolated version, but kit is with isolated version, pricing is USD 149,95

 

[abartels]

 
Sorry missed that as I'm not an I2S guy - so this board is different with regulation on the PS lines.  What a steal for $89!  If you run I2S - why not build one as a stand alone unit?  Could be better than all the other low cost DDCs we've been buying.  Total cost could be competitive.

 
I planned that before, but problem was that I wanted to build a universal DDC with I2S, AES and SPDIF support.
 
In the meantime I found a solution to build this, but I think I will go for the shortest I2S lines, so building a complete DAC.
 
Cheers   

 
 
Alex

 

[rb2013]

  I bought a cheap AK4495SEQ based dac (I2S ONLY) to test with, curious what AK449x chips can do,
if I like it I'm going to buy the complete diyinhk set and build it extensively with lots of R-Cores en lots of 0.8uV ultra low noise psu's.
 
http://www.diyinhk.com/shop/audio-kits/68-768khz32bit-ak4490eq-dac-i2sdsd-input.html#/dac_option-isolated_xmos_dac_and_led_pcb
 
Pricing: USD 149,95
 
There's an extended article on HifiDuino how to feed this DAC with seperated psu's for all stages, including left and right seperated.
It's also possible to buy 2 DAC's and set them in MONO mode, but pcb has to be modified for that.
 

AK4490EQ is a new generation Premium 32-bit 2ch DAC with new technologies, achieving industry’s leading level low distortion characteristics and wide dynamic range. The AK4490 integrates a newly developed switched capacitor filter “OSR Doubler”, making it capable of supporting wide range signals and achieving low out-of-band noise while realizing low power consumption. Moreover, the AK4490 has five types of 32-bit digital filters, realizing simple and flexible sound tuning in wide range of applications. The AK4490 accepts up to 768kHz PCM data and 11.2MHz DSD data.

This item includes PCB with all SMT component soldered, thru-hole component are not soldered.

*The XMOS PCB in the kit is flashed with our AK4490/4495 customized bit perfect volume control firmware, it send software command and switch AK4490/4495 between DSD and PCM playback. We are the first (since last year 2014) and still the only one (as of today 2015) in the major market can achieve DSD volume control from the PC os mixer bit perfectly. We are proud to ahead of the major market for at less one year. Please notes AK4490/4495 can only playback PCM when running in the default non software control mode.

Features:

1) 768KHz/32Bit AK4490 DAC Chip (industry’s leading level low distortion characteristics and wide dynamic range.)

2) Solid ground plane with careful split of digital and analog portion(a must for highest fidelity audio)

3) No Via in active circuit (via inductance always create jitter problem)

4) 0.1% Low noise thin film resistor and C0G Capacitor sourced from Digikey USA (guarantee no fake product from China)

5) 2200uF panasonc Low ESR capacitor at VREFH/L pin for super bass response and highest performance at 20Hz range frequency.

6) Gold plate I2S input connector and four GND return path dedicated for each I2S signal(lowest contact resistance and highest signal quality)

User guide:

1)The AK4490 PCB can work immediately with only I2S signal and power supply connected, one 3.3V (>300mA), one 5.0V (>100mA) and one +-12V (>100mA) regulated power supply in the default parallel operation mode.

2)For Diyer requires more deeper customization or switch to DSD playback(software I2C command is needed), the latest veraion of AK4490 datasheet is available in the official AKM website.

3)The PCB is designed to be DIY friendly. Diyer can cut the trace and uses the socket labelled AVDD_R(3.3V), DVDD(3.3V) for individual power supply to the Left and right analog power supply and digial supply.

4)The differential output directly from the DAC has labelled with preallocated 2.54mm spacing socket for diyer easily connecting to their favorite IV and LPF and bypass the default onboard one.

5) All dual opamp in single dip8 package IC can be used for this PCB output stage, such as OPA2134 AD8620 etc. One free opamp is included in the package and the model depends on stock.

6) Compact size 60mm x 60mm

Additional user guide when used with XMOS PCB flashed with our AK4490/4495 customized bit perfect volume control firmware:

1) Install jumper on AK4490 PCB PSN socket and SET it to LOW. The DAC will start to run in software control mode.

2) With our customized firmware, the audio data send to the DAC is always bit perfect and the volume control is done in the DAC chip. DSD volume control is available using the operating system mixer.

Without DAC specified firmware, the OS mixer will ruin the audio data if the volume is not set to full and DSD can only be playback at full volume.

Please notes the maxiumum sampling rate is limited by the XMOS PCB and it is 384k.

For advance user only when AK4490 is used with isolated XMOS PCB:

1) To avoid click noise occurs during replug of USB cable, remove FB1 and uses external 5v supply to CN3. Please notes reversed polarity or over voltage can damage the xmos chip immediately.

Specification:

1) I2S Input (MCLK, LRCK, BCK, DATA, GND)

2) Output level: 2V RMS

3) Resolution/Sampling Rate: Up to 32bit/768KHz

4) Supply: Regulated 3.3V, 5V, +-12V

*According to the AK4490 official datasheet page 44 notes 6 and our test, click noise occurs during power on/off, external mute circuit may be needed if click noise adversely affect system performance.

*Our latest D1X headphone amplifier includes power on delay and instant off output relay. It can mute the power on/off click noise of AK4495/AK4490 as well as all the other DAC chip requires this feature.

*For normal user, the newer AK4490 should be a better choice than AK4495. It can support upto 11.2Mhz DSD and it has better THD+N. AK4495SEQ is the first 768k DAC chip from AKM and it can be used as a reference for advanced user.

Very Cool!  I see they have a PCM1704 R2R kit as well!  If they came up with a tube output version I'd go for it!. 
 
But I sort bought that with the Lite DAC60 - for $500 - and it comes with the Rcores, case and control package.  So just went to work modding the heck out of it.
 
http://www.head-fi.org/t/740362/lite-dac60-pcm1704-r2r-tubed-dac-mod-project
 
Man does it sound awesome fed by the Hydra Z/Li Ion.

 

[abartels]

 
Very Cool!  I see they have a PCM1704 R2R kit as well!  If they came up with a tube output version I'd go for it!. 
 
But I sort bought that with the Lite DAC60 - for $500 - and it comes with the Rcores, case and control package.  So just went to work modding the heck out of it.
 
http://www.head-fi.org/t/740362/lite-dac60-pcm1704-r2r-tubed-dac-mod-project

 
The PCM1704 kit is without PCM1704 chip,,,

 

[rb2013]

   
The PCM1704 kit is without PCM1704 chip,,,

I saw that - mounting those not easy.  And the top PCM1704UK's are $65 each!  So the Lite DAC60 for me was the way to go.
 
The rewards have been beyond my highest expectations!

 

[rb2013]

   
The PCM1704 kit is without PCM1704 chip,,,

The advantage to their PCM1704 board if used with the XMOS/NDK I2S board - the NDKs would become the reclockers for the PCM1704s- NICE!
 
But I have a step down board that can take a 24.576 to 6.1 that I could use with seperate linear regulated PS to replace the DAC60 clock.  A lot of work so I just dropped in a Vanguard TXCO DIP14 T-T-H in to replace the cheapo Fox XO.  Simple drop replacement - made a small improvement.

 

[abartels]

 
The advantage to their PCM1704 board if used with the XMOS/NDK I2S board - the NDKs would become the reclockers for the PCM1704s- NICE!

 
Yep, and PCM1704 pcb is also fully isolated 

 
Don't know if they can solder pcm1704UK if sending them the chips

 

[rb2013]

   
Yep, and PCM1704 pcb is also fully isolated 

 
Don't know if they can solder pcm1704UK if sending them the chips

That would be good to know and how to run a seperate tube output stage from the IV lines

 

[abartels]

 
That would be good to know and how to run a seperate tube output stage from the IV lines

 
You can ask the shop, they always answer in a timely fashion

 

[rb2013]

   
You can ask the shop, they always answer in a timely fashion

Yes I might do that.  Might see if they would sell the board without the caps - as I would probably go with better ones anyway.
 
Still curious as to the SPDIF DXIO Pro3a with that Li Ion battery power - for my second system.  Hope they get some more in soon.
 
Alex - do you know which regulator they are speaking about "

world's lowest noise 1.0uV regulator from Analog Devices​

"?​