[b0bb]

1) Could you please clarify the modification proposed in post #18? I did not understand the transition before->after (pictures). Which WIMA polypropylene caps did you use? 63VDC 0,15µF MKP or FKP and what spacing (part number?)? How did you come up with the TX2575 249R00 0.05%? I did not find it in the Texas Components web shop. As you said, it is custom order only. Also a Y0706249R280T9L is hard to find in <1ku quantities. Are there equivalent or better quality alternatives which are easier to acquire?

The caps are WIMA MKP2 5mm mounting pitch.
There are actually 3 bypass cap per supply rail
220pf Corning low-K CGW Glass Cap, 0.15 uF Wima MKP2 and the existing 100uF Panasonic FC
The CGW caps are Military surplus, you can also use Silvered Mica which Mouser and Digikey sells.

The TX2575 is the best component for the job. This is the resistor that converts the DAC output current to a working voltage. You have to remove the original surface mounted resistor on the top side of the board and mount the TX2575 to the underside of the board. The value can be read off the original resistor's color bands or it can be measured.

Contact Texas Components directly via email, the values are custom made at no extra charge about 12USD each.

2) Did you install the TPS7A4700 5V regulators from TekDevice (post #37) only on the digital side? Can you suggest an alternative (equivalent or better quality) which is easier to acquire and can be installed without reworking the connections/footprint?

The TPS7A4700 from Tekdevice is the only board that I could find in the form factor, it has to be kept very small to preserve the high-frequency performance and low noise, there are better regulators like the LT3042 but none in this small a formfactor board.

3) In post #44 you mention an Abracon ABLNO femto clock and "Sanyo OSCON-G" caps. What are the specs and part number of the "Sanyo OSCON-G" caps? If the part number is 16SA47M, what would be alternatives easier to acquire? Should these caps be installed only for the ABLNO clock or also for the Crystek CCHD-950X? Which of the two clocks do you prefer? Is there a significant audible difference?

The Abracon is significantly better, the OSCON-G is not being made anymore 16SA47M is the correct partnumber. The Original Nichicon Muse FGs are not good enough for this type of application

4) Why did you use 14-pin as a socket connection for the crystal oscillator? What are the spacings/diameters? Can you recommend specific parts (part numbers)?

It is a standard 14pin DIP with the unused pins removed, socket allows for swapping and trying out different types of crystals.
http://www.digikey.com/product-detail/en/1107741/A462-ND/261894

5) Could you please confirm, amend or correct this part list (including quantities):
Looks OK.

Add 2x 100uFcaps for the Vcom bypass, these are big yellow ones next to the Vishay trimpots.
The link below are for MLCC caps
http://www.mouser.com/ProductDetail/TDK/C3216X5R1A107M160AC/?qs=sGAEpiMZZMukHu%252bjC5l7YRg09J0MvRVTf5Cn8LRREPo%3d

I used solid tantalums, they need careful handling and can explode if inserted the wrong way around.

There is > 500 USD of parts here, take it one step at a time.
This is a 4 layer board with a lot of copper ground planes, you need to have the correct equipment to avoid damaging the board.

 

[abartels]

1) Could you please clarify the modification proposed in post #18? I did not understand the transition before->after (pictures). Which WIMA polypropylene caps did you use? 63VDC 0,15µF MKP or FKP and what spacing (part number?)? How did you come up with the TX2575 249R00 0.05%? I did not find it in the Texas Components web shop. As you said, it is custom order only. Also a Y0706249R280T9L is hard to find in <1ku quantities. Are there equivalent or better quality alternatives which are easier to acquire?

The caps are WIMA MKP2 5mm mounting pitch.
There are actually 3 bypass cap per supply rail
220pf Corning low-K CGW Glass Cap, 0.15 uF Wima MKP2 and the existing 100uF Panasonic FC
The CGW caps are Military surplus, you can also use Silvered Mica which Mouser and Digikey sells.

The TX2575 is the best component for the job. This is the resistor that converts the DAC output current to a working voltage. You have to remove the original surface mounted resistor on the top side of the board and mount the TX2575 to the underside of the board. The value can be read off the original resistor's color bands or it can be measured.

Contact Texas Components directly via email, the values are custom made at no extra charge about 12USD each.

2) Did you install the TPS7A4700 5V regulators from TekDevice (post #37) only on the digital side? Can you suggest an alternative (equivalent or better quality) which is easier to acquire and can be installed without reworking the connections/footprint?

The TPS7A4700 from Tekdevice is the only board that I could find in the form factor, it has to be kept very small to preserve the high-frequency performance and low noise, there are better regulators like the LT3042 but none in this small a formfactor board.

3) In post #44 you mention an Abracon ABLNO femto clock and "Sanyo OSCON-G" caps. What are the specs and part number of the "Sanyo OSCON-G" caps? If the part number is 16SA47M, what would be alternatives easier to acquire? Should these caps be installed only for the ABLNO clock or also for the Crystek CCHD-950X? Which of the two clocks do you prefer? Is there a significant audible difference?

The Abracon is significantly better, the OSCON-G is not being made anymore 16SA47M is the correct partnumber. The Original Nichicon Muse FGs are not good enough for this type of application

4) Why did you use 14-pin as a socket connection for the crystal oscillator? What are the spacings/diameters? Can you recommend specific parts (part numbers)?

It is a standard 14pin DIP with the unused pins removed, socket allows for swapping and trying out different types of crystals.
http://www.digikey.com/product-detail/en/1107741/A462-ND/261894

5) Could you please confirm, amend or correct this part list (including quantities):
Looks OK.

Add 2x 100uFcaps for the Vcom bypass, these are big yellow ones next to the Vishay trimpots.
The link below are for MLCC caps
http://www.mouser.com/ProductDetail/TDK/C3216X5R1A107M160AC/?qs=sGAEpiMZZMukHu%252bjC5l7YRg09J0MvRVTf5Cn8LRREPo%3d

I used solid tantalums, they need careful handling and can explode if inserted the wrong way around.

There is > 500 USD of parts here, take it one step at a time.
This is a 4 layer board with a lot of copper ground planes, you need to have the correct equipment to avoid damaging the board.

 
Sanyo OS-CON devision has been taken over by Panasonic.
 
Look at SEPC series, they have lowest ESR values available. Sanyo OS-CON-G 16SA47M has 60mOhm ESR and 1830mArms ripple current.
Maybe you can try Panasonic 16SECPC100MW which has 10mOhm ESR and 4680mArms ripple current.

 

[b0bb]

   
Sanyo OS-CON devision has been taken over by Panasonic.
 
Look at SEPC series, they have lowest ESR values available. Sanyo OS-CON-G 16SA47M has 60mOhm ESR and 1830mArms ripple current.
Maybe you can try Panasonic 16SECPC100MW which has 10mOhm ESR and 4680mArms ripple current.

 
I recommend staying with the NOS OSCON-Gs, the current production OSCONS are actually hybrid Aluminium-Polymer caps and sounds very harsh and thin on the Abracon XO.
 
The Abracon XO is very picky about power supply decoupling, the high ripple current capacity of the SEPCs is largely wasted on the Abracon as it draws no more than 35mA.
 
Acronman Electronics in Singapore still sells them.
http://www.circuitdiy.com/product/oscon-16sa47m-sa-series-47uf-16v-electrolyte-capacitors

 

[abartels]

   
I recommend staying with the NOS OSCON-Gs, the current production OSCONS are actually hybrid Aluminium-Polymer caps and sounds very harsh and thin on the Abracon XO.
 
The Abracon XO is very picky about power supply decoupling, the high ripple current capacity of the SEPCs is largely wasted on the Abracon as it draws no more than 35mA.
 
Acronman Electronics in Singapore still sells them.
http://www.circuitdiy.com/product/oscon-16sa47m-sa-series-47uf-16v-electrolyte-capacitors

 
Hi B0bb,
 
Thanks for explaining, I wasn't aware of the bad audio quality of sepc. I suppose it's best to use in digital domain only?

 

[b0bb]

   
Hi B0bb,
 
Thanks for explaining, I wasn't aware of the bad audio quality of sepc. I suppose it's best to use in digital domain only?

The current production OSCON should only be used for the digital circuits only. Analog stuff is best handled by the Nichicon Muse series or Elna Slimic II
 
OSCONs are a mixed bag as far as potential improvement is concerned, OK for power supply filter duty, for other applications like supply bypass sometimes is a step backwards, some experimentation is needed.

 

[justbenice]

Hi b0bb , 
I got my MH-DA003 yesterday, i don't know why but my i/v converters look so difference with yours :
 
 

 
Do you know why ?

 

[justbenice]

Hi ,


I'v tried to attached image but the forum did not allow. I got my MH-DA003 yesterday and i found out that my I/V converters part look a lot differrence with yours in your picture. Do you know what happen ?

 

[b0bb]

  Hi ,
  I'v tried to attached image but the forum did not allow. I got my MH-DA003 yesterday and i found out that my I/V converters part look a lot differrence with yours in your picture. Do you know what happen ?

The I/V resistor is normally located where the white square in the middle of the picture.
In the stock LKS the 10k trimpot is blue.
 
In this picture, the I/V resistor has been removed.
 
If you have just joined the forum you have to wait a few days before you can post any pictures.
Take a few pictures of your unit and post it for comparison after the waiting period

 

[justbenice]

Thank you B0bb,
Do you still use Sonic Imagery opamp ? Was it a Sonic Imagery Labs 994Enh-Ticha DUAL Discrete OpAmp HDAM DIP8 ? 

 

[b0bb]

  Thank you B0bb,
Do you still use Sonic Imagery opamp ? Was it a Sonic Imagery Labs 994Enh-Ticha DUAL Discrete OpAmp HDAM DIP8 ? 

The answer is yes to both questions.

 

[nostoy]

Hello, drivers work well with Windows 10 ..... ??????????     ( LKS Audio MH-DA003 ( Volent)).

Thank you.

 

[justbenice]

Hi b0bb , have you ever tried the MUSE02 opamp ? And how do you compare it with the Sonic Imagery Labs ?
And do you think if we use a USB converter like DI-2014 from Audio-GD will make sound better ? I have 5m usb connect from my computer to my DAC and my DAC has already upgrade to ultra-low noise power supply Linear for Amanero USB boad and 2 clock chip to Crystek, so i wonder will the USB converter like DI-2014 will make thing better in my case ?

 

[abartels]

  Hi b0bb , have you ever tried the MUSE02 opamp ? And how do you compare it with the Sonic Imagery Labs ?

and did you compare with LME49720HA ?

 

[b0bb]

Here is the main criteria for opamp selection for the LKS.
 
Gain Bandwidth Product (GBW) around 50MHz
LKS uses a combined I/V and first stage low pass filter and it has to deal with a raw input of up to 23MHz (DSD512) so double that to get the bandwidth.
 
The I/V uses negative feedback to do its work so the opamp has to be fast enough to make the necessary corrections for negative feedback to work (sufficient phase margin for the loop gain LKS designed into the DAC).
 
This is critical to reduce transient and  intermodulation distortion (TID/IMD)
 
Output current 32mA or more.
The Sabre puts out 32mA@ full scale, and I want only Class-A operation, so opamp idle current needs to be >30mA.
Most DAC chips on the market put out between 2-4mA
 
Sonic Imagery Ticha 994
GBW: 50MHz  OK
Output current: ±150mA OK
Idle current: 30mA almost OK
 
Some of potential candidates mentioned
 
NJR Muses02
GBW: 11MHz Not OK
Output current: ±50mA OK
Idle current: 8mA Not OK
 
 
LME49720
GBW: 55MHz OK
Output current ±26mA Marginal in one direction
Idle current: 10mA Not OK
 
 
Will the 2 above work in practice ?
 
Sound will come out of the DAC, and it will be the brittle, scratchy and bright top end, that is the common complaint of Delta-Sigma DACs.
In the case of the MUSES02 there is also the midrange suckout at high sampling rates (>88kHz)  to deal with because of the insufficient bandwidth.
 
The harsh sound and smeared transients is in part due to TIM/IMD and the opamp moving between Class-A and Class-B while trying to deliver the large load current coming from the Sabre.
 
 
In order to get the liquidity without the harshness so beloved by the R2R crowd, the opamp in the Sabre's I/V converter needs to have the bandwidth/speed and the juice to do its work.

 

[b0bb]

  And do you think if we use a USB converter like DI-2014 from Audio-GD will make sound better ? I have 5m usb connect from my computer to my DAC and my DAC has already upgrade to ultra-low noise power supply Linear for Amanero USB boad and 2 clock chip to Crystek, so i wonder will the USB converter like DI-2014 will make thing better in my case ?

The DI-2014 and the Amanero onboard the LKS do the same thing, so no benefit.
 
Did your dac use a separate transformer for the Amanero power supply?
 
If not I suggest you install a separate transformer, the default method from Volent uses the existing transformer, this should be avoided as it bypasses the galvanic isolator on the LKS motherboard.