[Limpy]

Thank you for the answers.
 
As I read here
http://www.whatsbestforum.com/showthread.php?18580-Science-Thread-Review-of-Audioquest-Jitterbug-and-Uptone-Regen-USB-Conditioners
 
I'm not really convinced to use any USB thing (PPA or Regen) to make the SQ higher, but still reading...

 

[Muziqboy]

Just got a Melodious MX-U8 and using it un-modded via AES/EBU feeding a Theta DSPro Gen V-a dac. The sound is so glorious, I am at a loss for words to describe it. It is not even fully broken-in yet. 
 
I did change the fuse to a HiFi Tuning Supreme with a WA Quantum fuse chip on 1 end of the fuse. Also applied some Silclear Silver contact enhancer on the fuse holder and I.E.C. pins. Highly recommended!! 

 

 

[abartels]

Glad you like your Melodious-MX8 

 
I don't use a fuse in this device 

 
 
Regards,
Alex

 

[ccschua]

Modifications completed.
 
added TPS7A4700 LDO x 2 rail to each Crystek clock. Essentially the clock is galvanically isolated.
 
LT 3042 feeding 5V to overall circuit.
 
the improvement in transparency and PRAT is a big jump.
 
playing back Eric Bibb - Jesus Walk with Me. the guitar sound so real . Sara K. Cant stand the rain - the separation of instrument very distinct. Etta James - I would rather go blind. the acoustics is so sweet and extended. Roland campenhout - Eyesight to the blind - the Harmonica is glorious and guitar plucking is crisp and clear.
 
I am done modifications. (unless I am itch for the LT 3042 to the crystek.)
 
oh forget to mention, I have added diyinhk LT3042 to the PPA OCXO clock.

 

[abartels]

  Modifications completed.
 
added TPS7A4700 LDO x 2 rail to each Crystek clock. Essentially the clock is galvanically isolated.
 
LT 3042 feeding 5V to overall circuit.
 
the improvement in transparency and PRAT is a big jump.
 
playing back Eric Bibb - Jesus Walk with Me. the guitar sound so real . Sara K. Cant stand the rain - the separation of instrument very distinct. Etta James - I would rather go blind. the acoustics is so sweet and extended. Roland campenhout - Eyesight to the blind - the Harmonica is glorious and guitar plucking is crisp and clear.
 
I am done modifications. (unless I am itch for the LT 3042 to the crystek.)
 
oh forget to mention, I have added diyinhk LT3042 to the PPA OCXO clock.

 
Congrats 

 
Glad you got very positive results with your mods 

I like the track "Brick House" from Sara K. a lot, but "I Can't stand the Rain" also is a very good (sounding) song!
BUT
 
I am missing some pics 

 
 
Regards and keep up the good work,
 
Alex

 

[ccschua]

As this is proof of concept, components were installed loose couple with the fact my DIY skill is far from good, I have not shot any photo.

 

[ginetto61]

Originally Posted by abartels /img/forum/go_quote.gif...  
 
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,,,,,,,,,,,
 

 
Hi Alex and sorry to jump in and maybe go a little OT.
Very very interesting graph the one here above.
Do you think that this could be a general behaviour also for caps used with op-amps for voltage bypassing ?
Maybe increasing the value in an output stage can provide a better sound (at least at lower Hz i mean).
Thanks a lot.
Regards, gino

 

[abartels]

Hi Gino,
 
It depends on the design. The above graph is specifically for VREF behaviour AK4490 / AK4495.
Of course there are a lot of applications where increasing value of electrolytics improve SQ, especially buffer stages (PSU).
 
I many cases you have to experiment a little. If you want to increase value, just test with a cap in parallel and listen to it (and give it it's burn-in time)

 

[ccschua]

has anyone compared diyinhk xmos usb spdif. 
 
http://www.diyinhk.com/shop/audio-kits/97-xmos-192khz-high-quality-usb-to-spdif-with-ultralow-noise-1uv-regulator-wmanual-power-switch.html

 

[ginetto61]

Hi Gino,
It depends on the design. The above graph is specifically for VREF behaviour AK4490 / AK4495.
Of course there are a lot of applications where increasing value of electrolytics improve SQ, especially buffer stages (PSU).
I many cases you have to experiment a little. If you want to increase value, just test with a cap in parallel and listen to it (and give it it's burn-in time)

 
Thanks a lot Alex !
I am asking because i had a line preamp with 1000uF caps around the output op-amp and i liked the sound a lot.
I do not understand why some people seem to have an adversion for big caps in general.  I loved them.
Just like in the Audiobyte Hydra Power supply for instance
 
http://i274.photobucket.com/albums/jj263/durant24/hydra-zpm-internal_zpsgrz4hrau.jpg
 
Kind regards,  gino

 

[abartels]

   
Thanks a lot Alex !
I am asking because i had a line preamp with 1000uF caps around the output op-amp and i liked the sound a lot.
I do not understand why some people seem to have an adversion for big caps in general.  I loved them.
Just like in the Audiobyte Hydra Power supply for instance
 
http://i274.photobucket.com/albums/jj263/durant24/hydra-zpm-internal_zpsgrz4hrau.jpg
 
Kind regards,  gino

 
Hi Gino,
 
I like big caps in psu rails, low ESR (the lower the better, so the more in parallel the lower the ESR).
 
PSU Hydra-Z are ultracaps, very big capacitance, only 2.7Volts each so have to put them in series which results in 2xESR, but very nice.
They also are not that easily charged, special circuitry is needed.

 

[abartels]

  has anyone compared diyinhk xmos usb spdif. 
 
http://www.diyinhk.com/shop/audio-kits/97-xmos-192khz-high-quality-usb-to-spdif-with-ultralow-noise-1uv-regulator-wmanual-power-switch.html

 
Not sure but I thought member rb2013 had one ordered.
 
It seems a good device, with oscon caps for digital, but spdif only. Does your dac have I2S connection possibility?

 

[ginetto61]

Originally Posted by abartels /img/forum/go_quote.gif
Hi Gino,
I like big caps in psu rails, low ESR (the lower the better, so the more in parallel the lower the ESR).
PSU Hydra-Z are ultracaps, very big capacitance, only 2.7Volts each so have to put them in series which results in 2xESR, but very nice.
They also are not that easily charged, special circuitry is neede.

 
Hi and thanks again for the very valuable advice.
My point is that if we take two caps same series, same voltage but different uF
the bigger one has ALWAYS better measurements,  every parameter is so much better

It is clear here below if we compare, for instance,  the 220 uF piece with the 2200 uf piece ...
each and every spec is much better. I agree ...  they cost more ... they are bigger

 ... still ...
Small is not beautiful ... size does matter. 

 

 
Regards,  gino 

 

[Walderstorn]

Im considering this interface to go with a yulong d18, should i go with it or is there a better alternative up to that price point?
 
The Melodious will be kept stock probably.

 

[abartels]

  Im considering this interface to go with a yulong d18, should i go with it or is there a better alternative up to that price point?
 
The Melodious will be kept stock probably.

 
Hi Walderstorm,
 
When using it in stock version, probably Breeze U8 will be better, please ask rb2013, he has one and is very fond of it