[penguin69]

   The unbalanced output stage in the stock LKS opamps draws a negligible current on its input, the replacement Burson opamps you are using is expected likewise.
 
Drawing a load current from the I/V converter (U2 and U3) will compromise its performance, this is the reason for the large 1k resistors which isolates the load from the I/V converter, the reference 9018 output stage has an output impedance of around 4k which is quite high (aka drives long cable runs poorly)
 
The XLR output should only be used with active preamps, I use a Schiit Mjolnir which has no problem driving 25ft Canare Star quad XLR cables.

Thanks bObb. My pre-amp is quite an old one, but it has both an active and passive (Adcom GFP-750) mode, hence I can keep using the balanced output of the MH-DA003, which sounds extremely good as things stand. I use very short XLR cables, the Adcom pre seems to have no issue with these from an audibility perspective - I'm guessing that as long as I stay short I should be ok?
 
As an aside, the sound on my unit seems to be getting better and better - I think I've had it 3-4 months now? As mentioned before, it was almost unlistenable when I first bought it. The difference isn't at all subtle so this isn't positivity bias.
 
fjc36 - do you have a link to the new 9028-based LKS DAC? I did a quick search on the usual sites but couldn't find anything.

 

[fjc36]

Sorry, I have not hear one, but limited information to read the page on the Tao Bao network China , its on the recent sales list with 82fs clock (no change on the main OSC?),  it seems there is no face lift for the model MK II. Perhaps a re-design of the main board. I am very curious about it. It is the reason I postpone my purchase of the LKS MH-DA003 (dual 9018) and wait for the outcome of the LKS ES9028pro or ever 9038pro model。 Ask Bobb, has  any idea? I have waited four month on this.

 

[fjc36]

  

 

[fjc36]

Please see the attached graph LKS MH-DA003 MKII mainboard, to me, it seems as a direct replacement of the DAC chips only

 

[fjc36]

It did mention to use  LME49990 and OPA627 AU, any difference  on layout?

 

[fjc36]

https://world.taobao.com/item/540405847037.htm?fromSite=main&spm=a21m2.1.0.0
 
Here is the link, it is all Chinese, may be you can find a  link at the US site that sells LKS. This is a TaoBao site sells many many commercial items including Hi-Fi or mid-Fi gears and parts. 

 

[fjc36]

Look into the pictures of the main boards, they are identical, that perhaps indicate no new layout but a direct substitution of DAC chip only. I may ask sales of LKS on this.

 

[abartels]

Hi B0bb,
 
 
There's a new TCXO contender on the horizon, for audio frequencies, sadly NO 100mHz but standard 22.5792 / 24.576 / 45.1584 / 49.152
These have spectacular low Phase Jitter figures and very low Phase Noise figures too!
 
These are called: Golledge GXO-3306L (for 3.3V) see: http://www.golledge.com/docs/products/osc_sm/gxo3306.htm
 


 
I'm very confident they will show-up VERY competetive within your comparisson sheet 

 
 
Regards,
Alex

 

[b0bb]

  There's a new TCXO contender on the horizon, for audio frequencies, sadly NO 100mHz but standard 22.5792 / 24.576 / 45.1584 / 49.152
 

 
Here are the details
 
Phase jitter in the 10Hz-10kHz region normalized to operating frequency:
Golledge           GXO-3306           XO     fc=24.58MHz  BW=(10.00Hz-10.00kHz)     RMS Jitter: 178.651fs
 
NDK NZ2520SD as a comparison:
NDK                  nz2520sd 22M     XO     fc=22.58MHz  BW=(10.00Hz-10.00kHz)     RMS Jitter:  62.696fs
 
At 50ppm the GXO-3306 is an ordinary XO, TCXO have temp drift of 1-2ppm.
 
The datasheet is a marketing document.
Control calculation confirms datasheet numbers for phase jitter, picked at the high freq deviation end of the graph to make the numbers look good.
 
Golledge            GXO-3306/Control XO     fc=24.58MHz   BW=(10.00kHz-5.00MHz)  RMS Jitter: 37.151fs

 

[abartels]

 

  There's a new TCXO contender on the horizon, for audio frequencies, sadly NO 100mHz but standard 22.5792 / 24.576 / 45.1584 / 49.152
 

 
Here are the details
 
Phase jitter in the 10Hz-10kHz region normalized to operating frequency:
Golledge           GXO-3306           XO     fc=24.58MHz  BW=(10.00Hz-10.00kHz)     RMS Jitter: 178.651fs
 
NDK NZ2520SD as a comparison:
NDK                  nz2520sd 22M     XO     fc=22.58MHz  BW=(10.00Hz-10.00kHz)     RMS Jitter:  62.696fs
 
At 50ppm the GXO-3306 is an ordinary XO, TCXO have temp drift of 1-2ppm.
 
The datasheet is a marketing document.
Control calculation confirms datasheet numbers for phase jitter, picked at the high freq deviation end of the graph to make the numbers look good.
 
Golledge            GXO-3306/Control XO     fc=24.58MHz   BW=(10.00kHz-5.00MHz)  RMS Jitter: 37.151fs

Hi B0bb,
 
The specs indeed are commercialized, but I still don't understand why those numbers are that high since phase noise figures between 10Hz and 10kHz of GXO-3306L/A (25ppm) are lower than those of NZ2520SD
 
 NDK NZ2520SD 22.5792                    Golledge GXO-3306L/A 24.576
 
10Hz    -97dB                                      -101dB
100Hz  -127dB                                    -132dB
1kHz    -149dB                                    -155dB
10kHz  -161dB                                    -166dB
 
or am I missing something?
 
Regards,
Alex

 

[penguin69]

  https://world.taobao.com/item/540405847037.htm?fromSite=main&spm=a21m2.1.0.0
 
Here is the link, it is all Chinese, may be you can find a  link at the US site that sells LKS. This is a TaoBao site sells many many commercial items including Hi-Fi or mid-Fi gears and parts. 

Thanks for the link. I am UK based, I imported my last model from the Far East so I would have no problem doing the same again. 
 
Two questions for bObb:
  1) With the OCXO you used (or may still use), did you notice any difference in the sound as the oscillator was warming up? It would be interesting if it sounded a bit 'jittery' initially and then smoothed out after a few minutes.
  2) Do you have any views on XO vibration jitter/noise? Is this something to worry about in any way?
 
Thx!

 

[b0bb]

  Hi B0bb,
 
The specs indeed are commercialized, but I still don't understand why those numbers are that high since phase noise figures between 10Hz and 10kHz of GXO-3306L/A (25ppm) are lower than those of NZ2520SD
 
 NDK NZ2520SD 22.5792                    Golledge GXO-3306L/A 24.576
 
10Hz    -97dB                                      -101dB
100Hz  -127dB                                    -132dB
1kHz    -149dB                                    -155dB
10kHz  -161dB                                    -166dB
 
or am I missing something?
 
Regards,
Alex

The NDK numbers shown above are for the Crystek CCHD-957 22MHz, it is a near exact match to the phase noise plot supplied by Crystek.
http://www.crystek.com/crystal/spec-sheets/clock/cchd-957.pdf


I used the numbers from the DIYINHK Phase noise plot for the NDK, they appear consistent with the datasheet supplied by NDK.
http://www.diyinhk.com/shop/155-thickbox_default/ndk-nz2520sd-20ppm-ultra-low-phase-noise-oscillator.jpg


The red plot line gives the NDK numbers as
 
10Hz    -112dB                                     
100Hz  -140dB                                   
1kHz    -151dB                                   
10kHz  -157dB

 

[b0bb]

   
Two questions for bObb:
  1) With the OCXO you used (or may still use), did you notice any difference in the sound as the oscillator was warming up? It would be interesting if it sounded a bit 'jittery' initially and then smoothed out after a few minutes.
  2) Do you have any views on XO vibration jitter/noise? Is this something to worry about in any way?
 
Thx!

 
Comments to the questions
1)The Pulsar takes about 15mins to warm up, the Abracon AOCJY1 about 1 hour. The sound will be a little light on the low end as it warms up, your description is close to what I hear during the warm up.
 
2)Quartz cryatals are sensitive to large amplitude vibration, unlikely to be an issue unless you place the DAC on top of a subwoofer.

 

[abartels]

 

  Hi B0bb,
 
The specs indeed are commercialized, but I still don't understand why those numbers are that high since phase noise figures between 10Hz and 10kHz of GXO-3306L/A (25ppm) are lower than those of NZ2520SD
 
 NDK NZ2520SD 22.5792                    Golledge GXO-3306L/A 24.576
 
10Hz    -97dB                                      -101dB
100Hz  -127dB                                    -132dB
1kHz    -149dB                                    -155dB
10kHz  -161dB                                    -166dB
 
or am I missing something?
 
Regards,
Alex

The NDK numbers shown above are for the Crystek CCHD-957 22MHz, it is a near exact match to the phase noise plot supplied by Crystek.
http://www.crystek.com/crystal/spec-sheets/clock/cchd-957.pdf


I used the numbers from the DIYINHK Phase noise plot for the NDK, they appear consistent with the datasheet supplied by NDK.
http://www.diyinhk.com/shop/155-thickbox_default/ndk-nz2520sd-20ppm-ultra-low-phase-noise-oscillator.jpg


The red plot line gives the NDK numbers as
 
10Hz    -112dB                                     
100Hz  -140dB                                   
1kHz    -151dB                                   
10kHz  -157dB

 
 
Hi B0bb,
 
I'm ashame, I indeed took the wrong numbers

 

[b0bb]

   
 
Hi B0bb,
 
I'm ashame, I indeed took the wrong numbers

 
The Golledge GXO-3306 is not the lowest phase noise XO out there but it is still quite good, 9X lower phase jitter than the FOX FXU-HC73 you were looking at earlier.
Golledge          GXO-3306         XO     fc= 24.58MHz  BW=(10.00Hz-10.00kHz) RMS Jitter: 178.651fs
Fox                  FXU-HC73         XO     fc=156.25MHz BW=(10.00Hz-10.00kHz) RMS Jitter: 1605.452fs
 
It has 20% better drive capability than the NDK, risetime is 5ns vs 6ns for a 15pF load and may avoid the issues you were having with the NDK.
 
If you plan on getting a few to try out do it now while the UK is still part of the EU.