Melodious MX-U8 USB Interface 8 Core XMOS chip

[b0bb]

  messy work to prove concept. I tap 1 AC rail to LT 3042 (from LKS audio) and output to 5V dc. 
 
I just realise that xmos consumes 300 to 500 mA. the voltage drops to 4.4V. therefore I need another 3.3V to the crystek clock (for galvanic isolation). 
 

The LKS power supply is configured for 5V output, check to see if its working correctly.
 
Disconnect the board output from the Melodious.
 
Measure the voltage with nothing connected to the output, verify it is at 5V
 
Connect  a 5W resistor to the output of the regulator board and check it is 5V. Use 10ohm for 500mA, 15ohm for 333mA
 
See if the board puts out 5V in both cases, use the existing Melodious transformer as the AC power source.

 

[Abra]

I have got a warning not using the diyinhk LT3032 board:
 
"i would not recommend you diyinhk LT3042 0.8uV. After researching was revealed that it has congenital defect made by diyinhk. The high freq noise on Mhz area is spreading around everything and no possibility to fix it without removing transistor"
 
Any comments or solution for this issue?
 
Thanks.

 

[abartels]

  I have got a warning not using the diyinhk LT3032 board:
 
"i would not recommend you diyinhk LT3042 0.8uV. After researching was revealed that it has congenital defect made by diyinhk. The high freq noise on Mhz area is spreading around everything and no possibility to fix it without removing transistor"
 
Any comments or solution for this issue?
 
Thanks.

 
Can you reveal your source please?

 

[Abra]

I have got the info from a card owner in private msg.
Before purchasing this board with tempting parameters (the chip at least), I'm curious if anybody can confirm or confute? Is it a unique or a common feature of the boards?

 

[Wildcatsare1]

Hey all, I have rb2013's MX-U8 fired up and in my system. Cleaner, clearer window to the music, with an expansive soundstage, but maybe a tad brighter or less body than my Mac's optical out to the Monarchy M22B. Does this mirror anybody else's experience?

 

[abartels]

  I have got the info from a card owner in private msg.
Before purchasing this board with tempting parameters (the chip at least), I'm curious if anybody can confirm or confute? Is it a unique or a common feature of the boards?

 
I do not know what you are talking about, I don't own the equipment to measure EMI/RFI or some sort of other radiation, I only can tell
that this psu really does a good job within audio stuff.

 

[Abra]

You mean that you have this DIYINHK PSU, and sonically looks fine?

 

[abartels]

  You mean that you have this DIYINHK PSU, and sonically looks fine?

 
It's obvious you didn't read the thread,,,,,
 
See: http://www.head-fi.org/t/767935/melodious-mx-u8-usb-interface-8-core-xmos-chip/90#post_11735695

 

[Abra]

   
It's obvious you didn't read the thread,,,,,
 
See: http://www.head-fi.org/t/767935/melodious-mx-u8-usb-interface-8-core-xmos-chip/90#post_11735695

You are rigth, google search like "LT3042 diyinhk" directed me to another page of the topic. Thank you for the link.
I also like the sound of Cree schottkies as diode bridge, but  I used them in high voltage tube circuit. In low voltage applications old Motorola MBR ones are also appropriate for mee.

 

[abartels]

  You are rigth, google search like "LT3042 diyinhk" directed me to another page of the topic. Thank you for the link.
I also like the sound of Cree schottkies as diode bridge, but  I used them in high voltage tube circuit. In low voltage applications old Motorola MBR ones are also appropriate for mee.

 
Hi Abra,
 
You're welcome 

The Cree diodes are really good, I just put them in my new dac too, and it's a big improvement.
 
This very cheap chinese AK4495SEQ based dac, which I bought for testing purposes, amazes me!
It definitely will STAY!
 
As it has a designflaw I had to solder on it, and I decided to replace the 1N5401 diodes with the Cree C3D02060 ones.
 
Designflaw: The caps between VREFHL/VREFLL and VREFHR/VREFLR were 33uF only instead of 220uF stated in datasheet.
Further, as stated in evaluationboard datasheet of AK4490SEQ, THD+N at 20Hz (+) would improve by 8dB when using 2200uF caps,
I had to put two caps in parallel with those 33uF ones. Hifiduino states on their site that noisefigures probably would even getting better if choosing bigger values so
I decided to solder some 5600uF caps on the bottom of the pcb which definitely made a very good improvement!
 
Btw, there are a lot of AK4495SEQ based dacs  (also REAL expensive ones) which have same designflaw,,,,,,,,,,,
 

 
Some (badly taken) pics,,,,,
 

 

 

 

 

[Abra]

   
Hi Abra,
 
You're welcome 

The Cree diodes are really good, I just put them in my new dac too, and it's a big improvement.
 
This very cheap chinese AK4495SEQ based dac, which I bought for testing purposes, amazes me!
It definitely will STAY!
 
As it has a designflaw I had to solder on it, and I decided to replace the 1N5401 diodes with the Cree C3D02060 ones.
 
Designflaw: The caps between VREFHL/VREFLL and VREFHR/VREFLR were 33uF only instead of 220uF stated in datasheet.
Further, as stated in evaluationboard datasheet of AK4490SEQ, THD+N at 20Hz (+) would improve by 8dB when using 2200uF caps,
I had to put two caps in parallel with those 33uF ones. Hifiduino states on their site that noisefigures probably would even getting better if choosing bigger values so
I decided to solder some 5600uF caps on the bottom of the pcb which definitely made a very good improvement!
 
Btw, there are a lot of AK4495SEQ based dacs  (also REAL expensive ones) which have same designflaw,,,,,,,,,,,
 

 
Some (badly taken) pics,,,,,
 

 

 

 

 
Thank you.
After testing ES9018 and another ES9018K2M diyinhk boards, the next logical step would be to give a chance to the AK4495SEQ or AK4490EQ. They seems to be the best DAC chips of the delta-sigma world. Or continue with the tempting Soekris distcrete R2R DAC.
But I have changed my mind. It's time to try some high precision, multibit, non-audio purpose DAC chips. They are used in  industrial, defense and aerospace applications.
This is not a diy project like buying a few plug-and-play boards, adding the transformator and the box, and ready within one day. But my audio buddies can design and build both the DAC board's hardware and the necessary XMOS programming.
If it won't be successfull enough, the AKM chips and the Soekris discret DAC will be considered again.

 

[abartels]

   
Thank you.
After testing ES9018 and another ES9018K2M diyinhk boards, the next logical step would be to give a chance to the AK4495SEQ or AK4490EQ. They seems to be the best DAC chips of the delta-sigma world. Or continue with the tempting Soekris distcrete R2R DAC.
But I have changed my mind. It's time to try some high precision, multibit, non-audio purpose DAC chips. They are used in  industrial, defense and aerospace applications.
This is not a diy project like buying a few plug-and-play boards, adding the transformator and the box, and ready within one day. But my audio buddies can design and build both the DAC board's hardware and the necessary XMOS programming.
If it won't be successfull enough, the AKM chips and the Soekris discret DAC will be considered again.

 
AK4490 has better specs but AK4495 is the better sounding one. Will try mono setup later! Btw, AK4497 is coming, samples available in December, will sound like AK4495 with better specs than AK4490 

 
 
Soekris looks very nice, but I don't like the onboard psu. Would love to see a Soekris with possibility to feed ALL stages with external psu (without a lot of modifying pcb,,,),
thats why I didn't buy one
 
Keep us posted about your multibit / non-audio purpose dac chips based project, very interesting indeed!
.

 

[Abra]

   
AK4490 has better specs but AK4495 is the better sounding one. Will try mono setup later! Btw, AK4497 is coming, samples available in December, will sound like AK4495 with better specs than AK4490 

 
 
Soekris looks very nice, but I don't like the onboard psu. Would love to see a Soekris with possibility to feed ALL stages with external psu (without a lot of modifying pcb,,,),
thats why I didn't buy one
 
Keep us posted about your multibit / non-audio purpose dac chips based project, very interesting indeed!

 
We will se the results within a few month.

 

[Limpy]

Hi all,
 
First of all, I'm very happy to find this forum, lots of very useful infos about hifi. Respect to the writers.
I have a question about USB transports. Here's my system:
 
Yulong D18 DAC (without USB in) => Amp => Speakers
 
My plan is to feed this with my PC.
 
As I see in this forum the
http://www.ebay.com/itm/New-XMOS-U8-USB-Digital-Interface-DSD-PCM-I2S-AES-EBU-Coaxial-Optical-converter-/141026791919
transport can be good for this purpose. (with Talema supply)
 
My questions:
 
Which one is the best connection between the ( transport ) < = > ( DAC )    
SPDIF, optical, AES/EBU?
 
Is it worth to buy a special USB card (PPA V2 for example) into the PC for better sound? If yes, with dedicated PSU or not? My preferences are to spend money only if very neccessary.
I know this is abolutely personal. So, help for this: I'd like to buy this only if the quality difference is _very_ significant , not "after several comparison" or "after burned in" or "in some cases" or  "after listen it for weeks" ..etc. You know what I mean.. I'm a developer, working with PCs for years, so this fancy USB outs a kind of myth for me..
 
I'm new in music through PC, so this can be a silly question, sorry for that. My DAC don't support DSD. Is that means I absolutely wont play DSD files with this system
or can be played but lower sound quality than a DSD capable DAC?
 
Thank you!
 
Limpy

 

[abartels]

  Hi all,
 
First of all, I'm very happy to find this forum, lots of very useful infos about hifi. Respect to the writers.
I have a question about USB transports. Here's my system:
 
Yulong D18 DAC (without USB in) => Amp => Speakers
 
My plan is to feed this with my PC.
 
As I see in this forum the
http://www.ebay.com/itm/New-XMOS-U8-USB-Digital-Interface-DSD-PCM-I2S-AES-EBU-Coaxial-Optical-converter-/141026791919
transport can be good for this purpose. (with Talema supply)
 
My questions:
 
Which one is the best connection between the ( transport ) < = > ( DAC )    
SPDIF, optical, AES/EBU?
 
Is it worth to buy a special USB card (PPA V2 for example) into the PC for better sound? If yes, with dedicated PSU or not? My preferences are to spend money only if very neccessary.
I know this is abolutely personal. So, help for this: I'd like to buy this only if the quality difference is _very_ significant , not "after several comparison" or "after burned in" or "in some cases" or  "after listen it for weeks" ..etc. You know what I mean.. I'm a developer, working with PCs for years, so this fancy USB outs a kind of myth for me..
 
I'm new in music through PC, so this can be a silly question, sorry for that. My DAC don't support DSD. Is that means I absolutely wont play DSD files with this system
or can be played but lower sound quality than a DSD capable DAC?
 
Thank you!
 
Limpy

 

  Hi all,
 
First of all, I'm very happy to find this forum, lots of very useful infos about hifi. Respect to the writers.
I have a question about USB transports. Here's my system:
 
Yulong D18 DAC (without USB in) => Amp => Speakers
 
My plan is to feed this with my PC.
 
As I see in this forum the
http://www.ebay.com/itm/New-XMOS-U8-USB-Digital-Interface-DSD-PCM-I2S-AES-EBU-Coaxial-Optical-converter-/141026791919
transport can be good for this purpose. (with Talema supply)
 
My questions:
 
Which one is the best connection between the ( transport ) < = > ( DAC )    
SPDIF, optical, AES/EBU?
 
Yulong D18 doesn't have I2s otherwise I definitely would choose I2S, try AES/EBU, it's best option when using SPDIF.
 
Is it worth to buy a special USB card (PPA V2 for example) into the PC for better sound? If yes, with dedicated PSU or not? My preferences are to spend money only if very neccessary.
I know this is abolutely personal. So, help for this: I'd like to buy this only if the quality difference is _very_ significant , not "after several comparison" or "after burned in" or "in some cases" or  "after listen it for weeks" ..etc. You know what I mean.. I'm a developer, working with PCs for years, so this fancy USB outs a kind of myth for me..
 
Not sure if PPA V2 is the best option, could be worth a try to buy an Uptone USB Regen instead of PPA V2.
You could ask HeadFi member motberg about PPA V2 / Uptone Regen.
 
I'm new in music through PC, so this can be a silly question, sorry for that. My DAC don't support DSD. Is that means I absolutely wont play DSD files with this system
or can be played but lower sound quality than a DSD capable DAC?
 
Depends on your playback software. If using JRiver, it can downsample to 192kHz, but be sure your pc has sufficient processor power otherwise SQ will degrade.
 
Thank you!
 
Limpy