[gto88]

Thanks for affirming it.
And Have fun modifying it.

 

[justbenice]

   
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.

 
Hi bobb,
Thank you. Yes i hear some sound improvement now, the treble soften and not funny anymore. But it still thin. It may cause by the new part have not been burnin. I will wait a few more weeks to see.
My usb board using 2 crystek femto clock from the beginning, that why it high and very easy to short circuit with the upper board. But i don't think it can happen anymore,i apply a lot of pvc insulating tape layer in the back of the upper board already.
 After the  short circuit, the sound still same. I think the only damge is the transformer or, right ? Because the transformer is 7V-2A (10W) and the diods is 100V-7A-147 degrees celsius. With that spec, the diod still stay alive even if the transformer burn ?
 About the femto clock in the usb board, it was using during the short circuit so will it effect ? If something happen to it, will the sound worse alot ?
 I am not having a oscilloscope here so i just try to figure out what can be damge.

 

[b0bb]

   
Hi bobb,
Thank you. Yes i hear some sound improvement now, the treble soften and not funny anymore. But it still thin. It may cause by the new part have not been burnin. I will wait a few more weeks to see.
My usb board using 2 crystek femto clock from the beginning, that why it high and very easy to short circuit with the upper board. But i don't think it can happen anymore,i apply a lot of pvc insulating tape layer in the back of the upper board already.
 After the  short circuit, the sound still same. I think the only damge is the transformer or, right ? Because the transformer is 7V-2A (10W) and the diods is 100V-7A-147 degrees celsius. With that spec, the diod still stay alive even if the transformer burn ?
 About the femto clock in the usb board, it was using during the short circuit so will it effect ? If something happen to it, will the sound worse alot ?
 I am not having a oscilloscope here so i just try to figure out what can be damge.

The transformer shows obvious damage (bad smell, overheating).
 
Check the voltage out of the transformer is around 7V-9V, use the AC range on the multimeter and measure with everything connected and powered on.
 
Voltage across the Blue BC caps immediately after the Vishay diodes should be between 7-10V
Measure the voltage across the Kemet Tantalum to see that it is still at 5V
 
Compare the USB board with the original board that came with the DAC to see if it is better/worse than the original.

 

[justbenice]

Dear Bobb,
 
I'v measure  all the volt and everything just perfect ! I don't think there was a damage on those part. The only damaged is the transformer because it was got short circuit. I am waiting a new one arrive to replace.
 
The sound improve alot now, very clear and the treble is soft, not thin and funny like before.
 
The things is, i am gonna replace all the diods in the power section of the DAC board like you do. Do you think it will have good effect ? Good enough to make me  feel and hear it difference ?

 

[b0bb]

  The sound improve alot now, very clear and the treble is soft, not thin and funny like before.
 
The things is, i am gonna replace all the diods in the power section of the DAC board like you do. Do you think it will have good effect ? Good enough to make me  feel and hear it difference ?

 
Most of the mods to this DAC is for the purpose of keeping the topend/treble under control.
 
The Schottky diodes have much lower switching noise compared to the stock one in the DAC, replacing the diodes will reduce the top end harshness.
The particular Vishay diode mentioned will also add some body/bulk to the somewhat thin midrange of this DAC in its stock form.

 

[gto88]

Just received my DAC today. (DHL delivered it on Sunday).
The build quality is good, feel like a tank. And the remote is like a solid metal block.
Set it up right away, the sound is better than my existing iFi iDSD nano.
The bass is fuller, more impact. Music is more transparent.
BTW, I connect it to Audio-Gd NFB-1Amp and LCD-X in balanced mode.

PS, my remote didn't come with a battery, and I don't see any where indicate the
type of the battery, does any one happen to know the type?

PS, got it, battery: CR2032.

 

[jose1]

Hello,


I have just received DAC LKS MH-DA003, and I would like to know or power to order the interface Amanero USB with Crystek CCHD957 and the interface power supply.
Thank you

 

[justbenice]

Today i ordered pair of Muse01 and 20 Vishay diods, let see if it have good effect

 

[justbenice]

 
 My new dual MUSES01 op-amp and some new diodes for analog and digital power stage.
 Only 2 days burning but the MUSES01 hear a litle sweeter than the orginal.

 

[Kwan Choi]

Just received my DAC today. (DHL delivered it on Sunday).
The build quality is good, feel like a tank. And the remote is like a solid metal block.
Set it up right away, the sound is better than my existing iFi iDSD nano.
The bass is fuller, more impact. Music is more transparent.
BTW, I connect it to Audio-Gd NFB-1Amp and LCD-X in balanced mode.

PS, my remote didn't come with a battery, and I don't see any where indicate the
type of the battery, does any one happen to know the type?

PS, got it, battery: CR2032.

I got mh-da003 today, and I put cr2032 battery into remote control but remote control did not work. I found two pins left and right side. how can I configure the pins?

 

[gto88]

I tried to find the picture Shenzhen audio sent me, but I must have deleted it.
I don't recall two pins in the remote, all I remember is, you just push the battery
into the seat inside the remote, the battery "+" side face top (the side with print).
There is a pin which should touch the bottom of the battery when you push battery in place.
If there is another pin, then it should touch the top (or side of top).
If you still have problem, I can open my remote and take a picture.

 

[Kwan Choi]

Dear Gto88,
Please, help me.
I tried to put battery as you informed me, but still it does not work. I put one end of the pin to bottom but still it does not work.

 

[Kwan Choi]

Thank you, I found it.
I am really thankful for your advice

 

[gto88]

Glad it works for you now.

 

[justbenice]

Hi bobb,
 
 I replace all diodes in digital and analog side to Vishay Schottky ultra fast diodes  100V 8A, and sound get  better, smother and sweeter. But i see those transitors parts in red circle was pretty hot. I wonder should i replace it with better transitors ?