[b0bb]

   
Ok, some more questions regarding parts:
 
1) Which specific polystyrene caps do you recommend (bent and other)? What are the required parameters?
2) The 90 deg bent cap does not need to be matched, does it? Does it make sense to swap this in when leaving the original WIMA caps in place instead of the polystyrene caps which require matching?
3) Is the CGW CY06C221J the right glass cap to go for? You used a 220pF CGW cap, but wrote the linked 200pF CGW cap also works for this purpose. What are the limits to pick a cap within?
4) If my interpretation of the WIMA cap printing is correct, you used MKP2C031501H00JSSD caps (63VDC/40VAC), but you posted a link to MKP2D031501H00JSSD caps (100VDC/63VAC). The latter are much easier to find. Will they also work for this purpose or will they sound differently?
5) Does anyone know a good alternative to Accutek "4 Pin SOJ Crystal to 4 Pin (14 Pin Full Size) 300 MIL DIP with Site for Bypass Capacitor" (AK14D300-XTAL-04SOJ-BY) which was mentioned in another thread on head-fi (see post #1479)?

1)Siemens styroflex
2)It has to be matched to about 2% to avoid any perceptible channel imbalance
3)Anything between 200 - 1000pF will do, stick to the caps that fit the 5mm footprint and avoid the giant oversized audiophile stuff.
4)The substitute will work and is a lot easier to find.
5)You can also use the Twisted Pear Rhea boards, they are 50% more expensive
http://www.twistedpearaudio.com/digital/cronus.aspx

 

[b0bb]

  I closed cover but there is ~1mm between caps and cover...

Just put some electrical tape over the top of the cans.
 
The top over is quite thick and will not bend unless you put something really heavy on top of the DAC.

 

[justbenice]

  I closed cover but there is ~1mm between caps and cover...
It's working and it is worth to change amanero with femto clock and separate transformer. I went back to original OPA and I'm very happy from the music.

Yes, i found out that Amanero board with femto clock and separate power board + sparate transformer is MUST have if you want to have the best sound over USB interface.
I am waiting some part arrive from USA to change the femto clock near the ES9018 DAC chip to see if it improve sound. Also will change the WIMA cap and diods in Amanero power board.

 

[tribon]

  I am waiting some part arrive from USA to change the femto clock near the ES9018 DAC chip to see if it improve sound. Also will change the WIMA cap and diods in Amanero power board.

I'm also waiting for parts from USA to replace them in Amanero power board... I will not change femto clock on on the DAC.

 

[justbenice]

  I'm also waiting for parts from USA to replace them in Amanero power board... I will not change femto clock on on the DAC.

Yes, i have to change that Femto clock to CCHD 950X because i already change the i/v opamp to Ticha 994 but it doesn't fit well, the high treble sound very funny. Bobb said change the Femto clock to CCHD 950X will make that treble softer.

 

[tribon]

  Yes, i have to change that Femto clock...

I'm very happy after change of amanero and now playing on original OPA. I decided to postpone OPA swap for some time. I hope you will write something after change to Crystek.

 

[jose1]

hello everyone,


I am Spanish and new in the site, I have just bought DAC audio LKS MH-DA003, and interestedby the modifications of this device.


Thank you has all

 

[-Felix-]

[CGW Capacitor] Anything between 200 - 1000pF will do, stick to the caps that fit the 5mm footprint and avoid the giant oversized audiophile stuff.

 
b0bb, could you please explain how the CGW capacitors aid the frequency shaping at this point? I am still wondering ... If the CGW cap has a capacity of 200pf and is in parallel with a WIMA cap which has a capacity of 150000pf with an error of +/- 7500pf it cannot be about the additional capacity. Is it about the lower ESR for the 200pf?
 
Two additional questions regarding these capacitors:
Do they need to be matched? I found some 2%-470pf CGW caps. Can I use them without further matching?
I just discovered that you also put one CGW capacitor (?) next to each muses01 opamp. Should I put the same 2%-470pf CGW caps there too?

 

[justbenice]

  Yes, i have to change that Femto clock to CCHD 950X because i already change the i/v opamp to Ticha 994 but it doesn't fit well, the high treble sound very funny. Bobb said change the Femto clock to CCHD 950X will make that treble softer.

Yes, hopefully i got all the parts this week.

 

[b0bb]

   
b0bb, could you please explain how the CGW capacitors aid the frequency shaping at this point? I am still wondering ... If the CGW cap has a capacity of 200pf and is in parallel with a WIMA cap which has a capacity of 150000pf with an error of +/- 7500pf it cannot be about the additional capacity. Is it about the lower ESR for the 200pf?
 
Two additional questions regarding these capacitors:
Do they need to be matched? I found some 2%-470pf CGW caps. Can I use them without further matching?
I just discovered that you also put one CGW capacitor (?) next to each muses01 opamp. Should I put the same 2%-470pf CGW caps there too?

 
The 2% 470pF CGWs will do.
 
The performance of the glass cap at high frequencies (>10MHz) is superior to the metallized WIMA caps, this keeps the PSU rails properly decoupled in the 10-100MHz range.
 
I have not used the 470pF so it is up to you to experiment and report back.

 

[justbenice]

Dear Bobb,
I rebuild the Amanero power board like you and got some problem, i don't know why but the diods damn hot, my 10W separate transformer also get very very hot and have bad smell on it. I dont know what to do now Could you see the power board and tell me what to do :
 

 
This is what i did : 
 
Change 4 NFF14G BYW29-200 Diods to MBRF10H100 1444A 
Change a 470uf 35V cap to T530X337M010ATE004  - Tantalum Capacitors - Polymer SMD 330uF 10volts 20%
Change a blue cap to big red WIMA MKS2 10uF (10µF) 50V 5% pitch:5mm Polyester Film Capacitor
 
I take out the power board and shutdown the DAC waiting you

 

[justbenice]

Okay i know what happen to me. The back of new diods connect with the fron of the femto clock in the amanero board so it make my 10W transformer short circuits  :



I have to apply some paster to the  femto clock :




My question now is do i need to change another transformer for the one get short circuits?  It still work great now, I checked and there was no short-circuited inside the transfomer  but it did get very very hot and had bad smell in that time ! 

I'v also changed the main femto clock like you said and the treble better. I think it will be best after the femto clock burn in. Those Schottky Diodes & Rectifiers diods i changed in the amaneno power board work really great, it cooler than the original alot. I think i will chage all the diods in the main DAC.

 

[b0bb]

Okay i know what happen to me. The back of new diods connect with the fron of the femto clock in the amanero board so it make my 10W transformer short circuits  :



I have to apply some paster to the  femto clock :




My question now is do i need to change another transformer for the one get short circuits?  It still work great now, I checked and there was no short-circuited inside the transfomer  but it did get very very hot and had bad smell in that time ! 

I'v also changed the main femto clock like you said but i do not hear any improvement

Does it need burn-in again ?

 
The insulating enamel varnish on the transformer winding may be damaged, it should be replaced, this one possible reason for the bad smell from the enamel burning.
You run the risk of a fire if the it it stressed in any way for example being overloaded again in the future.
 
Clean up the black stuff around the areas of the short to prevent future problems.
 
There needs to be sufficient clearance between the upper board and the top of the crystal, at least 2-3mm
The black tape alone is not sufficient.
In my version there is 6mm separation between the top and bottom board.
 

 
The CCHD950X requires approx 2 weeks to completely burn in. It has to be powered on 24x7 during that time.
 
The Kemet Tantalum has a very long burn in time, about 3-4 weeks and it will sound quite bright during that time before settling in.
 
If you know someone with a high speed oscilloscope (>200MHz), this is useful to see if the Ticha is unstable or oscillating.
Changing the crystal produced a  difference for me not only on the LKS but on my other Sabre32 DAC (Yulong DA8).
If you are not noticing any difference, something else is off.
 
The other option is to put back the original USB interface to remove the change contributions from the upgraded board, it has new components and potentially damage from the short circuit.
Both can dramatically change the sound
The XOs on the board are fragile. If you have the scope, check that the output of the XOs on the USB board is still stable and not jittery.
 
You have changed many things at once, you have to do lot more work to isolate the individual contributions of the changes to see what worked and what did not work.
Allowance had to be made for burn-in time as well.

 

[gto88]

I am really curious that you guys are modifying a $1300 dac to make it sound better.
Please bare with me to ask, at $1300, isn't it good enough to cost so much.
How much difference can you get by going thru all the trouble, or is it just fun
to modify it?
I have to ask because I have ordered one out of its spec., and I am not the kind to modify such
expensive device.
Tell me it is worth it out of the box.

 

[justbenice]

  I am really curious that you guys are modifying a $1300 dac to make it sound better.
Please bare with me to ask, at $1300, isn't it good enough to cost so much.
How much difference can you get by going thru all the trouble, or is it just fun
to modify it?
I have to ask because I have ordered one out of its spec., and I am not the kind to modify such
expensive device.
Tell me it is worth it out of the box.

It just fun and hobbies, the DAC itself sound very good already. It was selling alot in China.