[dacusb]

 
Start with this post
http://www.head-fi.org/t/745032/lks-audio-mh-da003/105#post_12035366
 
Go back up to a few earlier posts to see how another person has done it.

Hi b0bb,
 
Thank you for your guidances: I will follow your recommendations on all the necessary mods as clearly suggested in above post. I have already ordered the Antek transformer as well.

 

[kazcou]

LKS MH-DA004 available :

Standard version
http://www.ebay.fr/itm/L-K-S-Audio-MH-DA004-Dual-ES9038pro-Flagship-DAC-DSD-I2S-Standard-USB-Edition-/182499967223?hash=item2a7dd880f7:g:3lgAAOSwTM5Y05Gd

Upgraded version
http://www.ebay.com/itm/L-K-S-Audio-MH-DA004-Dual-ES9038pro-Flagship-DAC-DSD-I2S-Upgrade-USB-Edition-/182499970553?hash=item2a7dd88df9:g:3lgAAOSwTM5Y05Gd

 

[Tomus4]

 
This is the only version I have tried, don't know about the older version, have not quite decided if I want to keep this DEXA in there long term.

Hi b0bb
Could you share your impression of using DEXA after over month playing?

 

[penguin69]

LKS MH-DA004 available :

Standard version
http://www.ebay.fr/itm/L-K-S-Audio-MH-DA004-Dual-ES9038pro-Flagship-DAC-DSD-I2S-Standard-USB-Edition-/182499967223?hash=item2a7dd880f7:g:3lgAAOSwTM5Y05Gd

Upgraded version
http://www.ebay.com/itm/L-K-S-Audio-MH-DA004-Dual-ES9038pro-Flagship-DAC-DSD-I2S-Upgrade-USB-Edition-/182499970553?hash=item2a7dd88df9:g:3lgAAOSwTM5Y05Gd

Despite my reservations posted earlier, I now have an LKS MH-DA004 in the post. It will replace my cooked 003.
 
If anyone has any questions around it, let me know.
 
I will give it a few days with the 575 xo but that will be the first component I strip out.

 

[b0bb]

  Hi b0bb
Could you share your impression of using DEXA after over month playing?

RCA section input on the LKS 003 comes from the balanced outputs, so I look for opamps that add as little colouration to the sound as possible.
That means no extra emphasis on the audio good or bad, perfectly neutral in presentation, I want as close as possible to the balanced outputs.
 
V5D added a very small amount of warmth and sweetness, the DEXA was perfectly neutral. I consider the advantage is with DEXA on this.
V5D's transient attack/response is slightly dulled compared to the DEXA which added nothing to and subtracted nothing from the sound.
 
No issues so far, DC offset is at output is below 5mV after being on for 60days, my headphone amp fed from the RCA output is directly coupled from input to output, so this is important to me.
 
Recommended pricing is excessive as it was not good enough for ES9018 I/V duties unlike the similarly priced Ticha994.
 
Parts Connexxion has the lowest price if you can get reasonable shipping to your part of the world.

 

[b0bb]

   
I will give it a few days with the 575 xo but that will be the first component I strip out.

 
Nice, looking forward to your impressions.
 
If the 004 responds well to 950X, this the time to leave this toy XO behind and get a real XO, the Pulsar.
I have absolutely no regrets with mine although the Wassenaar paperwork required for purchase was a real PITA.

 

[penguin69]

   
Nice, looking forward to your impressions.
 
If the 004 responds well to 950X, this the time to leave this toy XO behind and get a real XO, the Pulsar.
I have absolutely no regrets with mine although the Wassenaar paperwork required for purchase was a real PITA.

 

   
Nice, looking forward to your impressions.
 
If the 004 responds well to 950X, this the time to leave this toy XO behind and get a real XO, the Pulsar.
I have absolutely no regrets with mine although the Wassenaar paperwork required for purchase was a real PITA.

Yes b0bb, I'll put the 950 in for a short while (I have a couple at home so no extra cost) and then prepare for the Pulsar.
 
Shame that op amp rolling isn't possible. I now have a small collection of discrete op amps with no place to go (Dexa singles, doubles, Bursons ...). Time to put them on e-bay, perhaps, to raise some funds for the Pulsar.

 

[fjc36]

Glad to know someone orders a 004, and care about the XO. Please do not forget to keep the 003 on-hand during the testing and compare. Solid test always have to have a comparison. The A/B test from me always need last 2 minutes only and switch, because memory is short, impression sometimes not to accurate, making notes also.,I do not make blind test.And do not rush or jump to conclusion. Thank you.

 

[b0bb]

The current sale listings for the 004 do not list the AC voltage input the DAC takes.
I sent off an inquiry to Shenzen audio to see if they carry different input voltage versions of this DAC.
 
The China domestic market is 220V so countries in the EU and UK on 230V will get by but not the US/Japan on 100-120V

 

[Whitigir]

Voltage input for transformer can always be adjustable. Anyways, what is this Pulsar that will suppose t improve the performances ? I wonder if we can upgrade these transistors on 004

 

[Whitigir]

CCHD-950X

This is a starting point for experimentation and not a recommendation, it worked well with the 9018, the 9038 might behave completely differently so that is the downside.

LKS made a really strange choice using the large electrolytic for the XO regulator.
They look like Nichicon MUSE audio caps, this compromises the performance of the TPS7A47 regulator.
The MUSE caps perform very very poorly at the 100MHz range, most of the work is done by the small ceramic cap, the brown one on the side.

I normally expect to see low ESR solid polymer caps here.

LKS may have done this to dull out the sharp and harsh presentation of the 575-50.

I have marked the caps with the red "X" below, they probably need to be removed and replaced with regular solid polymer caps if the XO is swapped as the 950X does not require such drastic measures to bring it back into line.

These Capacitors have been changed into Jansen Capacitors, so Blob point was well taken. Now, I will be worrying about these output transistors and heat dissipation!!! Data sheet does states that 88-150C is ok with these guys

 

[penguin69]

  Alternatively buy or borrow an oscilloscope of at least 500MHz bandwidth and see if there is a clock pulse train coming out of the XO.
(Some of the old analog scopes might be had for cheap if you look around)
 
Basically if there is no XO signal, there will be no lock.

 
Hi b0bb
 
Just revisiting this advice from you. I dug out my existing oscilloscope recently and found that it offers a measly 20MHz bandwidth.
 
I've been on ebay looking for a more capable replacement, however the 500MHz units are selling for hefty sums, even the older refurb'ed or used models.
 
In your view would a more affordable unit such as the following be sufficient for analysing the 100MHz output of the XO's we have been discussing in this thread?
 
https://www.amazon.co.uk/Hantek-DSO5202B-200MHz-Digital-Oscilloscope/dp/B007GB41UQ/ref=sr_1_3?ie=UTF8&qid=1490538094&sr=8-3&keywords=oscilloscope+200mhz​
 
Thx.
pq

 

[b0bb]

   
Hi b0bb
 
Just revisiting this advice from you. I dug out my existing oscilloscope recently and found that it offers a measly 20MHz bandwidth.
 
I've been on ebay looking for a more capable replacement, however the 500MHz units are selling for hefty sums, even the older refurb'ed or used models.
 
In your view would a more affordable unit such as the following be sufficient for analysing the 100MHz output of the XO's we have been discussing in this thread?
 
https://www.amazon.co.uk/Hantek-DSO5202B-200MHz-Digital-Oscilloscope/dp/B007GB41UQ/ref=sr_1_3?ie=UTF8&qid=1490538094&sr=8-3&keywords=oscilloscope+200mhz​
 
Thx.
pq

 
200MHz BW is right on the limit, this is sufficient to determine if there is a signal present on the XO but not  enough to help with problems like output amplitude stability as the levels the scope reports will be suspect at the sampling limit.
 
200MHz is the Nyquist sampling limit for a 100MHz sine wave signal, for a square wave signal on the XO in the LKS  it should be at least 5X.
The clock will look like a very distorted sinewave on the 200MHz scope if it is present.
 
Ebay UK is pretty slim pickings right now, the US site is much better if any of the sellers are willing to ship to you.

 

[penguin69]

   
Ebay UK is pretty slim pickings right now, the US site is much better if any of the sellers are willing to ship to you.

 
Thanks b0bb, great advice - I've just ordered one now at a reasonable price.

 

[penguin69]

The MH-DA004 arrived today. I'm quite impressed with how quickly it arrived, actually: 8 days from e-bay payment, with the unit being shipped from Shenzen to Hong Kong and then on to the UK.
 
Externally, the unit is almost identical to my 003, aside from the fact that there is no rear power switch. My old remote control works with this unit, so I've left the other one wrapped up.
 
The new unit has 7 filters available for PCM, and 4 for DSD. And there are 16 DPLL Bandwidths avaiable.
 
I plugged it in, straight out of the box, just hoping that the thing would work as i had noticed a big dent in the inner box after superficial unpacking. I had no real expectations about the sound, since my 003 had been something of a disappointment when I first acquired it.
 
I got this unit going with 'Smoke on the Water', from Deep Purple's Made in Japan album. The sound was, from cold, probably on a par with my modified 003, which was a pleasant surprise and a good sign given that the 004 runs with the Crystek 575 xo, which was not to my liking in the older unit. The soundstage of the 004 appears slightly bigger and more controlled than that of the 003, but it's always hard to be a 100% sure of these things without an A-B comparison. It's definitely delivers a controlled performance though; I'm trying to pick faults with it at the moment but I am struggling. 'Good grip' seems to be a phrase I find myself repeating. The sound is also very 'airy', which I would guess are signs of low noise and low distortion.
 
I will give the unit a couple of weeks to burn in before I start getting adventurous. Promising signs though, from the outset.