[prot]

Thanks Gino!  You have the 9V transformer as well.  Same as my two.  I noticed the Melodious MX-U8 uses a better quality Talema transformer - at approx $175 USD I would love to try this one.




PS If they ever start selling on Ebay for US delivery I'd buy one for sure

The internals look very similar to U12. I like the much prettier case but would miss the U12 display (my Dac doesnt have one). Hopefully someone tries the melodious soon, curious to hear about it. Wont expect big SQ diffs though .. if any.

 

[rb2013]

The internals look very similar to U12. I like the much prettier case but would miss the U12 display (my Dac doesnt have one). Hopefully someone tries the melodious soon, curious to hear about it. Wont expect big SQ diffs though .. if any.

I see much better PS filtering - Wima caps  - better transformer.  Three clocks- in stead of two.  You never know

 

[conquerator2]

Componenents are only part of the story 

 

[prot]

I see much better PS filtering - Wima caps  - better transformer.  Three clocks- in stead of two.  You never know

All interesting diffs but may or may not be audible. My estimate is barely audible diffs, probably not enough to pass an a/b with eyes shut. But you are of course right, you never know until you hear it.

What impressed my most was the design. If it had a display I would've ordered one just to try. I'm a sucker for nice components and the melodious will stack up perfectly with my minimax. We'll see. It still looks like a nice & relatively cheap temp cure for upgraditis

P.S.
doesnt the U12 use 3 clocks too !? Two for audio freqs and one for the xmos itself.

 

[rb2013]

All interesting diffs but may or may not be audible. My estimate is barely audible diffs, probably not enough to pass an a/b with eyes shut. But you are of course right, you never know until you hear it.

What impressed my most was the design. If it had a display I would've ordered one just to try. I'm a sucker for nice components and the melodious will stack up perfectly with my minimax. We'll see. It still looks like a nice & relatively cheap temp cure for upgraditis

P.S.
doesnt the U12 use 3 clocks too !? Two for audio freqs and one for the xmos itself.

Yeah I like the design as well - I wonder if it would work with the WaveI/O ASIO drivers - like the U12. 
 
 
Yes there are three - but the U12 only has two TCXO clocks - the third is off to the left is non Temperature Controlled - I believe:

 

[conquerator2]

Well, according to Kingwa the difference between a toroidal and an R-core in the DI [they now offer it at an extra as an option] or converters in general - 'The R core sound may slight improve the transparency but not much'.
I have the regular toroidal one as that one wasn't available yet, but seems like I am in the clear. The DI needs no more transparency IMO. 

 

[rb2013]

  Well, according to Kingwa the difference between a toroidal and an R-core in the DI [they now offer it at an extra as an option] or converters in general - 'The R core sound may slight improve the transparency but not much'.
I have the regular toroidal one as that one wasn't available yet, but seems like I am in the clear. The DI needs no more transparency IMO. 

It's great they offer that as a very low cost option - like $20 extra.  Pretty awesome company

 

[conquerator2]

 
It's great they offer that as a very low cost option - like $20 extra.  Pretty awesome company

Yeah, except the units become 'outdated' pretty quickly. There's an update, revision or both every few months 

 

[rb2013]

  Yeah, except the units become 'outdated' pretty quickly. There's an update, revision or both every few months 

He's a perfectionist - and always pushing the envelope for better sound.  It doesn't make the older products sound different - just the newer better.
But I understand it does effect resale value - best to buy his last iteration on the used market.

 

[roman410]

Gustard U12 vs DXIO PRO3A http://www.diyinhk.com/shop/audio-kits/54-xmos-192khz-high-quality-usb-to-spdif-with-ultralow-noise-1uv-regulator-wauto-power-switch.html.
In terms of tonality, both devices are very similar. I found different in presentation. Overall sound of Gustard is laid back compare to DXIO, it is like sitting in 30rd vs 10rd. Also music from DXIO is more transparent, cleaner and clearer, better instrument separation and what I like most: holographic presentation. I run my source of music  Squeezebox touch and DXIO on 5V battery power., which is very easy, due to fact  DXIO have external power socket. What I do not like on DXIO is ugly yellow enclosure compare to Gustard.

 

[rb2013]

  Gustard U12 vs DXIO PRO3A http://www.diyinhk.com/shop/audio-kits/54-xmos-192khz-high-quality-usb-to-spdif-with-ultralow-noise-1uv-regulator-wauto-power-switch.html.
In terms of tonality, both devices are very similar. I found different in presentation. Overall sound of Gustard is laid back compare to DXIO, it is like sitting in 30rd vs 10rd. Also music from DXIO is more transparent, cleaner and clearer, better instrument separation and what I like most: holographic presentation. I run my source of music  Squeezebox touch and DXIO on 5V battery power., which is very easy, due to fact  DXIO have external power socket. What I do not like on DXIO is ugly yellow enclosure compare to Gustard.

Thanks!  So this runs on 5V DC - full version of Theyscon drivers! And pics of the inside?  Like clocks
 
PS found them


Oh - OXCO clocks!  If I read this correct - to bad no I2S output.

 

[rb2013]

Ok not OXCO but the graph shows the NDK NZ2520SD oscillator are really close to the OXCO and better then the highly acclaimed Crystek 957 clocks
 
http://www.diyinhk.com/shop/audio-kits/35-ndk-nz2520sd-20ppm-ultra-low-phase-noise-oscillator.html
 
The issue with this unit is the clocking scheme if it uses the same as this DIYHK USB interface:
https://hifiduino.wordpress.com/2014/01/24/
 

The “C7424Z” device is used as a clock divider to generate the 22.xx and 24.xx frequencies used by XMOS device and also used by the downstream device (the DAC). Seems the clock line to the XMOS device is also isolated in order to prevent any kind of noise leakage from the XMOS/USB side to the Clock/Clean side. 

Here is a link with jitter measurements on the XMOS:http://www.fetaudio.com/archives/1440
It shows jitter values of ~ 800 psec.​

I would expect that any clock signal going through some complex logic would result in several 100s psec of added jitter. 800 psec is kind of in the high end of added jitter; 2.5 nsec jitter is unexpected.​

I found the reference to the 2.5nsec: https://www.xmos.com/en/published/usb-audio-software-design-guide (p25)​

There it says that it is added to the SPDIF output when the master clock is “resampled” t the SDPIF clock domain (eg 44.1K, 96K, etc)​

in page 20, it talks about I2S:​

The L-Series device inputs MCLK and divides it down to generate BCLK and LRCLK.
To achieve this, MCLK is input into the device using the 1-bit port p_mclk. This is attached to the clock block clk_audio_mclk, which is in turn used to clock the BCLK port, p_bclk. BCLK is used to clock the LRCLK (p_lrclk) and data signals SDIN (p_sdin) and SDOUT (p_sdout). Again, a clock block is used (clk_audio_bclk) which has p_bclk as its input and is used to clock the ports p_lrclk, p_sdin and p_sdout. The preceding diagram shows the connectivity of ports and clock blocks.
​

This seems to imply that data is clocked by the derived clocks which are divided from the master clock. The expected added jitter from this kind of operation is “hundreds” of psec.​

However, there is a discussion of the added jitter to the I2S lines here [link].​

And according to this doc [link], the input clock (say the 24.576MHz clock) is sampled to the internal processor clock. Meaning that the external clock ticks (or transitions) are mapped to the processor clock ticks. This means that the worse “jitter” is when you just miss the external clock transition and must wait for the next internal clock tick. So the worse deviation from the actual frequency is the period of the processor frequency, thus for a 400MHz internal clock part, it is 2.5nS. This is the peak jitter. Thus the RMS number is 2.5/SQR(2)=700 psec​

 

 

[roman410]

Also i found different on XMOS chips. On DXIO number is 6U6C5 compare to Gustard 8U6C5 (6 vs. 8 core?).

 

[rb2013]

  Also i found different on XMOS chips. On DXIO number is 6U6C5 compare to Gustard 8U6C5 (6 vs. 8 core?).

Interesting -that is their code

 

[roman410]

I have detailed picture on board my DXIO,  unfortunately I do not have permission create attachments.