# LKS Audio MH-DA003



## nostoy

Hi, I have seen a new version of the DAC of LKS, someone on the forum has information, or had the opportunity to hear .....
 Leave the link:
  
 http://www.ebay.com/itm/Hi-end-LKS-Audio-MH-DA003-Double-Parallel-ES9018-DAC-decoder-USB-DSD-/111525053002
  
 I can not find reviews on internet.
  
 Many Thanks.


----------



## b0bb

This looks like LKS fixed up a lot of the complaints of the previous MH-DA002 model namely the use of 1970's era regulators in the powersupply. and cleaning up some of the poor signal routing.
  
 LKS has made a serious attempt  in improving the master clock as well as putting better in power supplies.
  
 I was originally looking at the Light Harmonic Geek Pulse Xfi, this new LKS DAC will give it some competition.


----------



## nostoy

A part of this:

 http://www.hiendy.com/hififorum/forum.php?mod=viewthread&tid=79247

 there is nothing else in the entire network. Only retail stores.


----------



## Chodi

I would check with these people in HK before buying. I believe they are the official distributor. http://www.mu-sound.com/9018d_index_en.html
  
 They don't show this new 003 version yet but they should have it unless L.K.S. changed distributors.


----------



## b0bb

Shenzhen Audio is also selling it
http://www.shenzhenaudio.com/l-k-s-audio-mh-da003-es9018-2-dual-channel-decoder-amanero-usb-dsd-dac-crystek.html


----------



## dspusr

http://www.htpc.jp/v4/index.html
 the difference is transformer
 HTPC 3 piece
 LKS 2 piece
  
 c.f. arcadia DA
 http://www.arcadiada.com/
 http://blogs.yahoo.co.jp/saikihiroshi/GALLERY/show_image.html?id=32292617&no=0


----------



## Chodi

dspusr said:


> http://www.htpc.jp/v4/index.html
> the difference is transformer
> HTPC 3 piece
> LKS 2 piece
> ...


 
 So the real question is: Who is actually the designer of this project? Is it LKS in China or this Japanese company in your post? My money is on the Japanese company buying or copying the design from LKS. I see they have silk screened their name on the pcb. That suggests that they at least commissioned their own version. I think only the people in HK that were/are the distributor know the real story. It would certainly be interesting to know who really owns this design. If I had to guess, I would say that Arcadiada in Japan made some sort of deal with LKS so that they could market the product exclusively in Japan at an inflated price.


----------



## nostoy

http://www.volent.com.hk/?page_id=672


----------



## prot

The tech sheet sounds very good. Looks good too and the price is reasonable. 
Anyone who can post some listening impressions?


----------



## prot

This is suposed to be quite popular in china/hk, none of our asian members tested it?!
Just wanna know if the amount of buzzwords in the product description does really translate into audible SQ improvements. Maybe a short comparison with some better known models in the 1-2K price range .. like AGDs, EElectric, Benchmark, Mytek, etc .. or some more expensive models if it truly punches above its paygrade


----------



## b0bb

Had mine for a few months now, a nice dac and quite a bit better then my Yulong DA8.
 The Yulong sells for around the same price.
  
 General description
 ===============
 The parts used in the DAC  are of very high quality and test out to be genuine.
 The advertising copy for this dac has a lot of buzzwords, I found to my surprise it did not fully describe the features of the dac.
  
 Hirez PCM DXD and DSD256 works as advertised, using it with Audirvana and the Raspberry Pi 2
  
 One major thing the standard LKS blurb did not emphasize was that the USB interface was galvanically isolated as was the I2S interface.
 This was a pleasant surprise when I opened up the dac.
  
 Technically this dac is much better implemented than the previous MH-DA002 and avoided the hamfisted use of the old linear regulators.
 This dac uses the LT1763 ultralow noise regulators.
  
 Each dac has the critical AVcc 3.3V supplied with its own regulator.
 The 1.2V digital and analog core supplies share the same requlator, unfortunately, but each dac has its own regulator,
 a little annoyed as to why LKS decided to penny pinch at the last moment, old habits die hard...
  
 Sound quality
 ============
 Presentation especially presence of the performance is much better than the DA8, the stock LKS tends to the bright side like a lot of ES9018 units.
  
 On really complex passages the Yulong can sound confused and incoherent but the LKS is not affected, bass extension and lower midrange presentation is superior to the Yulong, material like the double bass and cello sound quite muddy on the Yulong in comparison.
  
 I am using this with the HD800/Mjolnir and SR009/SRM-007T2. The former combination is unforgiving on bright material.
  
  
 Upgrade potential
 ==============
 Where the LKS comes into its own is when a modest amount of modification done.
  
 The bright topend of the ES9018 is made much worse by the use of the Crystek CCHD575, this is a femto clock.
 The sound is hard and etched. I replaced it with Crystek CCHD-950X which give it a more balanced presentation.
  
 The stock LKS (as with most Sabre32 DACS) is not very liveable on the HD800/Mjolnir combo.
 The Crystek 950X makes both the HD800 and SR009 sound good without any treble hardness.
  
 The stock opamp  used in the current to voltage converter idles at about 7-8mA,
 the ES9018 used as a 8-channel mono device requires the opamp to handle up to 32mA of current.
 LKS used the opamp in virtual earth configuration and has to sink and source this current completely,
 otherwise the ES9018 will flip and flop from current mode into voltage mode and back again.
  
 This means part of the output stage of the opamp is no longer operating in class-A beyond 25% of its operating range,
 that means the opamp drops out of Class-A operation at round 7-8mA.
  
 The replacement opamp is a discrete unit from Sonic Imagery which operates in Class-A up to 30mA.
 Still a little short of the ES9018's fullscale output but is significant step up from the stock unit.
  
 Replacing the I/V opamp improved the transient attack of the material while taking the hard edge off the sound,
 quite surprised how mellow the HD800/Mjolnir combination sounded without losing any of the clarity and transparency.
 (Mellow, Mjolnir and HD800 is something I would not use in the same sentence in normal circumstances) .
  
 On the SR009. I can hear the initial transient of hammer hitting the membrane kick drum, normally it is a dull thud on the Yulong.
 None on the clarity is lost on the SR009.
  
 The other major improvement came with replacing the integrator caps in the I/V converter with matched polystyrene caps.
 The stock Wima FKP2s were quite marginal. Some of the copperfoil polystrenes are visible in the pictures.
  
 The unbalanced section used 2 dual opamps which were replaced with the NJR Muses01 FET opamps
  
 I have also replaced the main output filter caps of the various voltage regulators of the digital parts of the dac with Sanyo OSCONS and Nichicon R7 FPCaps. The original Nichicon Muse caps were really quite unsuited to the job of providing low-ESR and high ripple filtering capability to the fast changing power demand transients of the digital side of the DAC.
  
 Picture of the DAC internals
  

  
 Closeup of the I/V converters.

  
 Future mods
 ==========
 Vishay Z-foil resistor for the I/V conversion resistors
 Vishay foil trimmers for the offset pots
  
 Future comparisons
 ===============
 Waiting for Schiit to get their schiit together and ship the Yggdrasil so that I can get one and compare.


----------



## nostoy

Thanks for all this information .... I'll be waiting for more ....


----------



## prot

@b0bb
Many thx for all that info, pretty much what I was asking. A side by side compare with the iggy would be very useful too ... or any other DAC that you have. 

And a few extra Qs:
1. I am quite happy with the Sparkos opamps in the minimax plus dac, any idea if those will fit? (more details http://www.tnt-audio.com/accessories/sparkos_ss3602_e.html)
2. how's the quality of the Usb input? Do you think an spdif converter like the gustard u12 is still necessary?
3. how about the pc drivers? Stable? Asio & wasapi ok? Any extra features or just plain drivers?


----------



## b0bb

prot said:


> @b0bb
> Many thx for all that info, pretty much what I was asking. A side by side compare with the iggy would be very useful too ... or any other DAC that you have.
> 
> And a few extra Qs:
> ...


 

 Comments on the questions:
 1)The Sparkos SS3602 will fit, I tried pair of them on the LKS.
  
 2)No complaints on the USB, it is made by Amanero, it is used by Yulong on the DA8 and I bought a few of them for my other projects like the Soekris R2R DAC.
 If the bitstream clocks on the U12 are upgraded I expect it to make an improvement. I would use the LVDS I2S output rather than the SPDIF to the LKS.
  
 3)I am not using the PC


----------



## AKAI

Hi Bob:
Thanks for the review, do you happen to have the pin configueration for the HDMI I2S output?

I own a Wyred4Sound Dac2, similar ESS 9018 chip. I just ordered an Audio-GD DI-2014 with HDMI I2S output to be used with my W4S DAC2. 

Wonder if theLKS pin arrangement is the same?

Thx

MP


----------



## b0bb

akai said:


> Hi Bob:
> Thanks for the review, do you happen to have the pin configueration for the HDMI I2S output?
> 
> I own a Wyred4Sound Dac2, similar ESS 9018 chip. I just ordered an Audio-GD DI-2014 with HDMI I2S output to be used with my W4S DAC2.
> ...


 

 Note this is an *INPUT* not output


----------



## AKAI

b0bb said:


> Note this is an *INPUT* not output


 
 Thanks again Bob, my set up will be Vortexbox -> Audio GD DI - 2014 HDMI I2S -> W4S DAC2. Looks like LKS input is a different than the PS Audio.
 Here is the Audio-GD HDMI I2S output configuration which I believe matches PS Audio and W4S.
*I2S-HDMI mode pins define:*
 Pin 1 : SDATA - (DSDR-)        Pin 2 : GND                     Pin 3 : SDATA + (DSDR+)
 Pin 4 : SCLK + (DSDL+)          Pin 5 : GND                    Pin 6 : SCLK - (DSDL-)
 Pin 7 : LRCK - (DSDCLK-)        Pin 8 : GND                    Pin 9 : LRCK + (DSDCLK+)
 Pin 10: MCLK +                      Pin 11: GND                    Pin 12: MCLK -
 Pin 13: NC                             Pin 14: NC                       Pin 15: NC
 Pin 16: NC                             Pin 17: GND                     Pin 18: NC
 Pin 19: Auto on control 
  
  
  
 Here is the I2S data compiled by Sonore.
https://docs.google.com/spreadsheet/ccc?key=0AgVhKcl_3lHfdFhNT0xWQnNVWTI1QjhTdXVGVThiYnc&usp=sharing#gid=0
  
 LKS HM DA003 looks really good, I was thinking about getting one (only if I can use the I2S). I may just send my W4S DAC2 back for an upgrade to the DSD SE version instead. I do have a Marantz SA 8005 which can handle DSD via USB but thinking about a stand alone DAC unit.


----------



## b0bb

Next stage of my LKS MH-DA003 mod.
  
 a) Vishay Z-Foil resistors  used to convert the ES9018 output current to a voltage
  
 b)Replace bipolar offset adjustment trimpot, this is a highly temperature sensitive part of the DAC, the Vishay foil trimpots have very low temperature coefficients compared to the original blue Bourns Cermet units
  
 The Vishay Z-Foils bring increased definition and added enhancement of the big soundstage, for the first time there is a distinct front and back separation of the soundstage on headphones beyond a simple layering of the soundstage.
  
 I found that this mod creates a soundstage that accurately places the instruments and musicians in a 3D space.
  
 Before pictures

  
  
 After:
 Vishay Z-Foil resistors soldered to underside of the boards
 Add WIMA polypropylene power supply bypass caps.

  
  
 Next installment:
 High voltage schottky diodes for power supply rectifier bridges.


----------



## prot

a first review online ... good enough as a first but I wish there was more info about the soundstage, imaging and SQ in general
https://sites.google.com/site/computeraudioorg/home/mini-reviews/l-k-s-audio-mh-da003-dac-review


----------



## prot

Another guy who seems quite happy with it (polish, use a translate engine) http://najlepszeodtwarzacze.pl/LKS_MH-DA003_femto.php
And seems to have some sort of brother device http://www.ebay.com/itm/YSDZ-DA-03-FPGA-DSD-Dual-ES9018-XMOS-USB-DAC-Amanero-Comho384-Mytek-Stereo-192-/121626123448


b0bb had a chance to test ir need that schiit dac?


----------



## b0bb

prot said:


> @b0bb had a chance to test ir need that schiit dac?


 
 I have decided to wait a few months on the Schiit for the hype to die down.


----------



## Chodi

prot said:


> Another guy who seems quite happy with it (polish, use a translate engine) http://najlepszeodtwarzacze.pl/LKS_MH-DA003_femto.php
> And seems to have some sort of brother device http://www.ebay.com/itm/YSDZ-DA-03-FPGA-DSD-Dual-ES9018-XMOS-USB-DAC-Amanero-Comho384-Mytek-Stereo-192-/121626123448
> 
> 
> @b0bb had a chance to test ir need that schiit dac?


 
 My first thought was that this new dac was just a repackaged LKS oem board but that does not seem to be the case. They are very different. I have no idea who this YSDZ company really is? They list it as a DA-03 which is a clear reference to the LKS but internally they look very different. It is nearly impossible to get any details on these from users or reviewers. Only way to judge it would be to buy one. Anyone ready to take a bullet for the group?


----------



## prot

b0bb said:


> I have decided to wait a few months on the Schiit for the hype to die down.




Quite a lot of noise yes and lots of fanboy 'reviews' that are just not credible. Should be a good Dac though. 




chodi said:


> My first thought was that this new dac was just a repackaged LKS oem board but that does not seem to be the case. They are very different. I have no idea who this YSDZ company really is? They list it as a DA-03 which is a clear reference to the LKS but internally they look very different. It is nearly impossible to get any details on these from users or reviewers. Only way to judge it would be to buy one. Anyone ready to take a bullet for the group?




The Dac board is quite diff but the general layout & design are strikingly similar .. plus the naming. It's either that the chinese are cloning each other nowadays or some of the same ppl/companies are involved. 
Quite surprised about the lack of info too, the LKS seem popular around asia and there should be many asian members around here.


----------



## b0bb

chodi said:


> My first thought was that this new dac was just a repackaged LKS oem board but that does not seem to be the case. They are very different. I have no idea who this YSDZ company really is? They list it as a DA-03 which is a clear reference to the LKS but internally they look very different. It is nearly impossible to get any details on these from users or reviewers. Only way to judge it would be to buy one. Anyone ready to take a bullet for the group?


 
 It is quite a different design from the LKS, the digital power supply section looks quite well done, I can see at least 4 ADP150 type regulators around each Sabre32. The FPGA could be interesting if there was more information.
  
 The USB interface looks an older XMOS design, it is definately not an Amanero design which uses a custom CPLD and not an off the shelf chip.
  
 The interface USB  board looks hacked up, I can see footprints on the PCB for a SPDIF transformer and SPDIF optical receiver.
 Does not appear to be galvanically isolated, unlike  the 2 LKS models.
  
 YSDZ appear to have spent time adding the all analog filter and I/V stage and this is quite unique.
  
 The analog power supplies do not have any heatsinking, it may be just a capacitance multiplier and not a full blown voltage regulator.


----------



## Chodi

b0bb said:


> It is quite a different design from the LKS, the digital power supply section looks quite well done, I can see at least 4 ADP150 type regulators around each Sabre32. The FPGA could be interesting if there was more information.
> 
> The USB interface looks an older XMOS design, it is definately not an Amanero design which uses a custom CPLD and not an off the shelf chip.
> 
> ...


 
 You certainly seem to have a grip on their layout. I also question the implementation of the Amanero but there is clearly an Amanero pcb mounted. It is strange that they would list xmos in the title along with Mytek 192? I don't know what that has to do with anything? There is certainly no xmos usb that I can see. I also noticed their use of an extensive analog filter I have not seen anything like that. Certainly the parts count is higher than the LKS which is using opamps. It looks as if the design was originally intended for xmos and they changed it for the Amanero to allow for ease of dsd.


----------



## soundlook

Q to b0bb: since all of upgrades you discrybed looks tempting what would it take to perform them on my MH-DA003?


----------



## b0bb

soundlook said:


> Q to b0bb: since all of upgrades you discrybed looks tempting what would it take to perform them on my MH-DA003?


 
 All of the parts used are available off the shelf from suppliers like Mouser and Digikey.
  
 The Class-A discrete opamp is from Sonic Imagery Labs
 The Vishays were custom ordered from Texas components.
  
 Cost and effort wise this is one of the simpler mod jobs I have done.


----------



## b0bb

chodi said:


> You certainly seem to have a grip on their layout. I also question the implementation of the Amanero but there is clearly an Amanero pcb mounted. It is strange that they would list xmos in the title along with Mytek 192? I don't know what that has to do with anything? There is certainly no xmos usb that I can see. I also noticed their use of an extensive analog filter I have not seen anything like that. Certainly the parts count is higher than the LKS which is using opamps. It looks as if the design was originally intended for xmos and they changed it for the Amanero to allow for ease of dsd.


 

 I am not sure what they are using for the USB, pictures are not clear enough.
 It is not an Amanero, the LKS uses the Amanero USB interface, it is the small green rectangular board in the top right corner of the picture my LKS below


----------



## Chodi

b0bb said:


> I am not sure what they are using for the USB, pictures are not clear enough.
> It is not an Amanero, the LKS uses the Amanero USB interface, it is the small green rectangular board in the top right corner of the picture my LKS below


 
 The YSDZ is also using a daughter pcb mounted in the rear corner. I agree it does not look like an Amanero pcb but they may have updated their board. I have heard for some time that Amanero was coming out with a new board to solve their dsd 512 problems. Some said they could do it with a firmware upgrade but that never came. It would be interesting to know. I sent them a request for conformation about Amanero or xmos usb. Let's see what they have to say.


----------



## kazcou

I think YSDZ is more like this DAC than LKS, same remote, same usb board (listed as XMOS)


----------



## b0bb

kazcou said:


> I think YSDZ is more like this DAC than LKS, same remote, same usb board (listed as XMOS)


 

 Is there a link to this other non LKS DAC similar to the YSDZ you are referring to?


----------



## kazcou

I forgot to put the link : http://item.taobao.com/item.htm?spm=a230r.1.14.172.tFEFUm&id=43696131338&ns=1&abbucket=9#detail
 It's another DAC, but they use the same remote and same usb board, and you can see clearly is a XMOS board


----------



## kimmkimaster10

,


----------



## b0bb

Next installment of my LKS MH-DA-003 mods
  
 High voltage Schottky rectifiers, these devices are fast recovery, compared to conventional diodes these use the majority carrier conduction mechanism.
  
 These are 100V 8A devices from Vishay.
  
 Analog side.

  
 Digital side


----------



## b0bb

Nichicon FPcap R7 aluminum polymer caps for the DAC  3.3 Analog Vcc and 1.2V digital suppliers
  
 These are capable of delivering peak currents of 5A/


----------



## b0bb

Evox/RIFA PHE series precision (1%) metalized 33nF polypropylene.
  
 This is part of the output filter for the unbalanced section.
  
 NJR Muses01 fet  opamp is visible on extreme left of picture.
 Rectangular black box next to opamp is a 100pf Corning Glass capacitor used for bypassing the opamp powersupply


----------



## b0bb

TI TPS7A4700 Ultra low-noise regulator for the DAC AVcc pre-regulator.
  
 This replaces the LT317A regulator.
  
 The TPS7A4700 is comparable to the LT317 for power supply ripple rejection but very low noise, about 5uV vs about 200uV for the older LT regulator.
  
 This regulator operates over a wider bandwidth up to 10MHz vs the 100kHz bandwidth of the LT regulator.
 The adapter board is made by TekDevices and they have a WebShop and an Ebay Store.
  
 Regulator before output filter cap is reinstalled

  
  
 Picture of regulator with mounting completed.


----------



## prot

sounds like youre building a new DAC there .. got some sound imressions too ?


----------



## kimmkimaster10

I will try to do the tuning
 Is history about the tuning and tuning pictures and tuning parts and give sent by e-mail?
 kimmkimaster10@gmail.com


----------



## b0bb

kimmkimaster10 said:


> I will try to do the tuning
> Is history about the tuning and tuning pictures and tuning parts and give sent by e-mail?
> kimmkimaster10@gmail.com


 
  
 The opamps are the easiest to replace as they are socketed.
  
 The big discrete opamp is from is the Ticha 994 from Sonic Imagery Labs
 http://www.sonicimagerylabs.com/products/Model994DiscreteOpAmp-Ticha.html
  
 The unbalanced output uses the NJR Muses01
 http://www.njr.com/MUSES/MUSES01.html
  
 The major modification parts listed below.
  
 The Nichicon FP Caps 16volts 470uF R7 part numbers are RNE1C471MDN1PX.
 Available from Mouser or Digikey

  
 The Schottky rectifier diodes are 100V 10A from Vishay part number MBRF10H100-E3/45
 Available from Mouser or Digikey

  
 The Blue 63V 0.033uF/33nF 1% polypropylene is from EVOX/Rifa. Part number PHE426DJ5330FR17T0
 Available from Mouser or Digikey

  
 The Vishay 249ohm Z-Foil resistors are part number TX2575 249R00 0.05%
Available from Texas Components (www.texascomponents.com)

  
 Vishay 10K foil trimmer partnumber 1260W 10K000 5.0%
 Available from Texas Components (www.texascomponents.com)

  
 TI TPS7A4700 5V regulator from TekDevice
 http://tekdevice.com/chapter2/index.php?route=product/product&path=25&product_id=87
 Note: Requires rework of connections to fit LT317 footprint

  
 The Crystal oscillator is the Crystek CCHD950X-25-100
 Available from Mouser or Digikey


----------



## b0bb

prot said:


> sounds like youre building a new DAC there .. got some sound imressions too ?


 

 Parts of the DAC rebuilt with higher quality components and to fix some of the loose ends in the LKS implementation.
 I bought the LKS with this specific purpose.
  
 Sound quality comments are subjective.
  
 I am looking for a neutral DAC that works with my LCD-3F, HD800 and SR009.
  
 The latest set of mods improve the instrumentation separation and soundstage, I am getting front to back separation in addition to side to side separation, quite nice on the live recordings.
  
 The bright forward presentation commonly associated with Sabre32 implementations has been eliminated, this is accomplished without compromising the fine resolution and exceptional microdetails of the Sabre32.
  
 Loud complex passages do not suffer from compression and image blurring that was common with the unmodded LKS and unmodded Yulong DA8.
  
 As it stands, the  modded LKS exceeds my Soekris DAM1021 R2R DAC running the latest filters.


----------



## stuart1927

bObb mentioned "The bright topend of the ES9018 is made much worse by the use of the Crystek CCHD575, this is a femto clock.
 The sound is hard and etched. I replaced it with Crystek CCHD-950X which give it a more balanced presentation"
  
 Is changing out easy to do? I.e. is it a plug in or does it need soldering etc?
  
 I already changed the opamps to the sonic imagery and noticed quite an improvement. It seems this might be the next biggest potential improvement...but I'm not experienced with soldering!
  
 Many thanks!
  
  
  
 Stuart


----------



## b0bb

stuart1927 said:


> bObb mentioned "The bright topend of the ES9018 is made much worse by the use of the Crystek CCHD575, this is a femto clock.
> The sound is hard and etched. I replaced it with Crystek CCHD-950X which give it a more balanced presentation"
> 
> Is changing out easy to do? I.e. is it a plug in or does it need soldering etc?
> ...


 

 The original crystal is surface mounted (SMT), removal required the use of SMT rework tools, I used a temperature controlled hot-air wand to remove mine and I replaced it with a 14pin socket so that I can try out various crystals.
 It takes about 15mins to slowly heat up the board on both sides, the crystal can then be picked up with a pair of tweezers once the solder melts.
 Slow heating prevents the board from warping.
  
 Changing the crystal will change the sound signature of the LKS quite significantly


----------



## b0bb

This is the Abracon ABLNO femto clock with a jitter spec of 50fs (12kHz-20MHz) with a nominal 12ppm stability.
 http://www.abracon.com/Precisiontiming/ABLNO.pdf
  
 I have had this one few a few months but was never satisfied with its performance up until now, in many ways it is similar to the Crystek CCHD575 that came stock with the LKS.
  
 The sound was overly bright but the low end extension was much better than the CCHD575, overall the LKS was not as satisfying to listen to as the CCHD950X.
  
 I decided to give it another try after installing the TPS74A7 ultralownoise regulator and the Sanyo OSCON-G caps, these are the purple ones in the picture.
  
 After about 36hours, the presentation of the LKS really opened up, in particular the pace, rhythm, attack and timing (PRAT).
 The slight veil on the LCD-3F lifted and the bulky phones started to disappear, on the HD800 and especially the SR009 the bass slam became harder, lower and deeper
  
 Overall an unexpected improvement, it is quite finicky as far as powersupply is concerned.

  
 Some of the more interesting specs, in all cases lower number is better
  
 XOs I like.
 ABLNO 50fs jitter, 12ppm stability, -93db@10Hz close in phase noise performance
 CCHD950X 500fs jitter, 25ppm stability, -86.4db@10Hz close in phase noise
  
 Original XO:
 CCHD575 82fs jitter, 50ppm, -90db@10Hz
  
 Abracon specs the jitter up to 20MHz but Crystek measures the jitter over 80MHz, so the advantage of the Abracon is not as much as it appears to be.
  
 The LKS performance with the  CCHD575 did not improve with the new regulator.
 I might try another bypass mod to see if it helps things.


----------



## b0bb

New USB interface from LKS. This is a modified Amanero USB interface using the Crystek CCHD957 low jitter clocks and ultra-low noise regulators.
  
 This is what I was hoping Amanero would have offered from day one, no software change as it still looks like the Amanero interface to the host computer.
 I got this from Volent in Hong Kong.
  
 Unit comes with its own power supply, not sure if it is a Volent or LKS design.

  
 Side view of assembled board stack with power supply on top and the USB interface below.

  
 Interface installed inside the LKS MH-DA003.
 It is a perfect fit as expected for an accessory board from the manufacturer.

  
 I am running mine with its own separate 10VA 7V AC transformer, this preserves the galavanic isolation provided by the LKS DAC.
  
 Sound impressions:
 -Widens the already big soundstage of the MH-DA003, bringing a greater sense of breadth and depth.
 -The wooly low-bass has been cleaned up, it is a lot more solid  and defined, on the LCD-3F, the apparent weight of the bass is both heard and felt, there is an obvious visceral impact.
 -This change is one step closer to the elimination of the ES9018 tizzy top end, with the new USB interface, the rendering of the clash of cymbals is clear with all the transients intact, without being overly bright.
 -Overall more analog sounding, much of the digital etch and glare is gone.


----------



## m0reilly

b0bb, how did you order the part? i'm looking over the volent site atm...


----------



## b0bb

m0reilly said:


> b0bb, how did you order the part? i'm looking over the volent site atm...


 

 Contact them directly, email is on their website
 http://www.volent.com.hk/?page_id=54
  
 I ordered from Ben, PM me, if you need Ben's email


----------



## m0reilly

thanks for that


----------



## alex-dsd

Hi b0bb,
  
 Your review is very informative, thank you. Yesterday I got my LKS 003 DAC.
 I have a couple of questions about the DAC and could not find an answer on the internet.I hope you can help.
  
 1. I do on-the-fly conversion from PCM to DSD256 (thanks to Chodi for a good tip on conversion in general). When I play a 16-bit FLAC the LKS panel says DSD256x. But when I play a 24-bit FLAC, the panel says "UN-LOCK". Do you know what that means? The sound seems to be O.K. in both cases.
  
 2. In SACD section of Foobar properties, when I select DSD mode almost all settings are grayed out. In PCM mode all settings are available. Can it be an LKS specific issue, or something is wrong with Foobar settings?
  
 Thank you in advance, Alex


----------



## kazcou

alex-dsd said:


> 1. I do on-the-fly conversion from PCM to DSD256 (thanks to Chodi for a good tip on conversion in general). When I play a 16-bit FLAC the LKS panel says DSD256x. But when I play a 24-bit FLAC, the panel says "UN-LOCK". Do you know what that means? The sound seems to be O.K. in both cases.
> 2. In SACD section of Foobar properties, when I select DSD mode almost all settings are grayed out. In PCM mode all settings are available. Can it be an LKS specific issue, or something is wrong with Foobar settings?


 
 1. the problem is not the bit rate, is the sampling rate.
 For all multiple of 44100hz DSD = 2.8Mhz DSD128 = 5,6Mhz DSD256 = 11,2Mhz
 and for 48000hz DSD = 3,05mhz DSD128 = 6,1Mhz DSD256 = 12,2Mhz
 Amanero is not handling properly DSD256 for 48000hz multiple
  
 2. for DSD mode you can't change the volume, the sampling rate and the filter because you are not doing any conversion, it is a native play mode.


----------



## alex-dsd

kazcou thanks for the reply.
  
 1. It makes a lot of sense. Have you come across this "UN-LOCK" message on the LKS DAC display. Do I need to do anything about it?
  
 2. I have a small comment. I have two versions of Foobar. One is the standard version. The other one is from Artt Adea-1 site (http://www.arttlabs.com/foobardsd-mini-player) modded by Artt Labs.
  
 All settings are available at the Artt Foobar DSD mini version under DSD mode. That made me suspicious about my standard Foobar settings. If something is wrong with the settings maybe it domino affects the sound quality.
  
 Thank you again, Alex


----------



## kazcou

alex-dsd said:


> kazcou thanks for the reply.
> 
> 1. It makes a lot of sense. Have you come across this "UN-LOCK" message on the LKS DAC display. Do I need to do anything about it?
> 
> ...


 

 1. I got the same message, if I convert a 48khz (or 96khz or 192khz or 384khz) file to DSD256 (or take a 16bit 44,1khz and use PPHS to convert it to 48khz). Since we get sound, it is just a display problem...
  
 2. Even with all settings available, this does not mean you are using it. When you are playing a native DSD file, if you set the volume to +0db or 6db... you will get the same output level. And I think the mini player is just using a old version of sacd pluging, that why all settings are always available.


----------



## alex-dsd

Sounds like I am in a good shape. I appreciate your comments, it's good to have some support from a colleague having more experience on the subject. Especially taking into account the fact that we should expect no miracles from mu-sound support. I sent an inquiry regarding fuse and drivers to mu-sound and got a miserable reply.
  
 Thank you,
 Alex


----------



## b0bb

alex-dsd said:


> Hi b0bb,
> 
> Your review is very informative, thank you. Yesterday I got my LKS 003 DAC.
> I have a couple of questions about the DAC and could not find an answer on the internet.I hope you can help.
> ...


 
 "UN-LOCK" on the display means the DAC is not getting a recognized signal from the Amanero interface. The Saber32 has a digital PLL so it is tracking the DSD bitstream the best it can and it is why you still have sound, the Sabre32 may resample or interpolate the input if it misses the occasional sample.
  
 Have you tried just plain decoded  PCM, I think the sound quality might be better given this case as the PLL can lock on the precise sample rate and there is no data loss.
  
 Not a Foobar user so I will defer to the already present responses.


----------



## alex-dsd

b0bb,
  
 Thank you for your comments regarding the Amanero interface.
  
 As for plain decoded PCM, I will definitely compare the sound quality between non converted and up converted PCM. I do hope the PCM flac files up converted to DSD256 sound better because this is the main reason why I bought this DAC. Alex


----------



## Chodi

alex-dsd said:


> b0bb,
> 
> Thank you for your comments regarding the Amanero interface.
> 
> As for plain decoded PCM, I will definitely compare the sound quality between non converted and up converted PCM. I do hope the PCM flac files up converted to DSD256 sound better because this is the main reason why I bought this DAC. Alex


 
 Instead of foobar give HQPlayer a try. They have a free sample available. That unlock you are getting on the display is a software communication problem. It may be your settings in foobar. I think you will find the results with HQP to be better. You should be getting 11.2 on your display when upsampling to 256 regardless if your flac is 24 or 16bit. If you are not it is a software problem. Probably something simple in your settings.


----------



## alex-dsd

Chodi, thank you for comments. The settings issue in Foobar was the first thing that I thought about. By the way, I have two versions of Foobar, the second one is the DSD modded version from Artt ADEA-1 site. Both versions give me the "UN-LOCK" warning.
 In fact I can live with the "UN-LOCK" warning if I know that PCM flac files are up converted to DSD256 on-the-fly correctly with a clear progress in SQ. So I will not be willing to return to my previous music listening habits after that. That was the main reason for buying the LKS MH-DA003 DAC. 
  
 Of course, I will give HQPlayer a try. Alex


----------



## Chodi

alex-dsd said:


> Chodi, thank you for comments. The settings issue in Foobar was the first thing that I thought about. By the way, I have two versions of Foobar, the second one is the DSD modded version from Artt ADEA-1 site. Both versions give me the "UN-LOCK" warning.
> In fact I can live with the "UN-LOCK" warning if I know that PCM flac files are up converted to DSD256 on-the-fly correctly with a clear progress in SQ. So I will not be willing to return to my previous music listening habits after that. That was the main reason for buying the LKS MH-DA003 DAC.
> 
> Of course, I will give HQPlayer a try. Alex


 
 If your display is not showing 11.2 then there is something set wrong. In foobar go to preferences and then output/asio. Double click on foo dsd asio (which is you output diver). In setting box that appears under pcm to dsd make certain you are set for dsd256 and choose sdm D. Other setting will work but we are just trying to correct your problem here. Under advanced setting reset everything to default. If you are still having problems pm me. You are not getting the correct timing at dsd 256 if your display shows "unlocked" although you will get music.


----------



## b0bb

Check the DPLL bandwidth, it is accessible from the front panel buttons or the remote, try AUTO or WIDE, try the other DPLL options in the menu to see if it makes a difference.
 This may help with the timing of the DSD stream.


----------



## alex-dsd

It was on AUTO. Tried them all one by one, no difference, the same UN-LOCK.


----------



## Chodi

b0bb said:


> Check the DPLL bandwidth, it is accessible from the front panel buttons or the remote, try AUTO or WIDE, try the other DPLL options in the menu to see if it makes a difference.
> This may help with the timing of the DSD stream.


 
 His problem is a software problem. Nothing wrong with the dac. I sent him a pm to fix this.


----------



## alex-dsd

kazcou said:


> 1. the problem is not the bit rate, is the sampling rate.
> For all multiple of 44100hz DSD = 2.8Mhz DSD128 = 5,6Mhz DSD256 = 11,2Mhz
> and for 48000hz DSD = 3,05mhz DSD128 = 6,1Mhz DSD256 = 12,2Mhz
> Amanero is not handling properly DSD256 for 48000hz multiple
> ...


 
 Thank you kazcou, I also asked Maxim, the developer of ASIOProxy and he confirmed that it should be grayed out in Tools / SACD under DSD mode.


----------



## alex-dsd

b0bb, In an attempt to fix the "UN-LOCK" issue I tried HQP. Spent 5-6 hours hitting my forehead against the HQP wall with ALL types of settings. It did not work for me, so I do not know if HQP can resolve the "UN-LOCK" issue. Any advice would be appreciated. Alex


----------



## kazcou

maybe you should send a email to amanero and see if they can help you to modify the firmware


----------



## alex-dsd

b0bb, please disregard my SOS appeal. I took a look at my Task Manager and noticed that my system while experiencing issues with HQP did not show any overload in terms of CPU and memory usage. I thought about unnecessary services polluting my system. So I run Fidelizer, and then used the settings kindly shared by Chodi  and HQP got re-animated !!! Now I can upsample 16/44, 24/88, 24/96, 24/176, 24/192 to DSD256, and my DAC shows DSD256x on it's panel each time.
 I still need to explore all available settings to see (hear) what suits me best.
 So my strong recommendation to anybody experiencing an unclear / unusual behavior of HQP first check if any weights are handcuffed to the system's balls. 
  
 Thank you for all your time and effort. Alex


----------



## Narcissus

I'm interested to know how the DSD 256 sounds on the LKS DAC, do you'll prefer the PCM or DSD? Is there a huge difference between PCM & DSD?


----------



## alex-dsd

Hi,
 It is important to note that my DAC is connected to my amplifier with RCA cables. Probably the overall impression would be different with XLR cables. Also do not exclude Foobar from comparison, especially when playing the up-sampled 24-bit PCM files.
  
 In general, my initial impression is that HQP is very good in up-converting 16/44 flacs to DSD256. I think this conversion is HQP's strength.
 As for PCM 24/96 and 24/192 - I do not quite understand if there is any difference between Foobar and HQ Player when up-sampling them to DSD256.
 The up converted DSFs are good enough but probably I expected more pronounced difference between DSD64 and up-sampled DSD256. The numbers are misleading, when you move up from DSD64 to DSD128, the sound quality will not double. In general, to my ears, high frequency is a little bit excessive in case of DSD playback. 
  
 All the filters are a bit of a jungle to my ears. I have listened to several filters and after 30 minutes of comparing they start sounding very similar, and then they are not easy to choose from. 
  
 I have not compared PCM playback with DSD playback. I am more interested in exploring the DSD concept. 
 Regards, Alex


----------



## Narcissus

"I have not compared PCM playback with DSD playback. I am more interested in exploring the DSD concept."

Right, I'm interested too in the DSD concept, especially the 256 which everyone says sounds awesome & is a huge step up. I'm surprised you don't find any difference between 64 and 256, could be some setting issues, no?

Other thread contributors like b0bb, Chodi, Kazcou Might want to share their opinion/views.

Tx


----------



## alex-dsd

Most likely it is a combination of several factors. I really like the 16/44 sound up-converted to DSD256.
 I am still at the beginning of the learning curve, hope the right settings will make the difference. On the other hand I am realistic about my equipment and do not expect miracles.
 Alex


----------



## Narcissus

alex-dsd said:


> Most likely it is a combination of several factors. I really like the 16/44 sound up-converted to DSD256.
> I am still at the beginning of the learning curve, hope the right settings will make the difference. On the other hand I am realistic about my equipment and do not expect miracles.
> Alex




But ofcourse it always is, a combination of several factors. Most importantly room acoustics/treatment, having said that i personally have high expectations about playing dsd256 and believe that in a well engineered DAC it makes a HUGE difference (read magical). For example the Lampizator Big 7 which plays out of the world music experience especially on DSD 256 as reported by hundreds if not thousands of owners worldwide (sigh, if only they were cheaper)....


----------



## alex-dsd

I agree that budget is an issue. I am considering selling my LKS MH-DA003 once realized that will not be able to build a system matching LKS.
 Alex


----------



## stuart1927

So...my problem with the LKS MH-D003 is that it will play dsd128 files stored on my LG G4 phone via usb, but when I try dsd256 is say's error decoding (message on phone screen when using usb audio pro). Does anyone know if the issue is with the audio pro app? I don't think so as the dsd256 files play ok via my ifi micro idsd dac (again using the LG G4 as file host/player).
  
 Any advice greatly appreciated.
  
 Stuart


----------



## MINORISUKE

stuart1927 said:


> So...my problem with the LKS MH-D003 is that it will play dsd128 files stored on my LG G4 phone via usb, but when I try dsd256 is say's error decoding (message on phone screen when using usb audio pro). Does anyone know if the issue is with the audio pro app? I don't think so as the dsd256 files play ok via my ifi micro idsd dac (again using the LG G4 as file host/player).
> 
> Any advice greatly appreciated.
> 
> Stuart


 
 This question is a kind of FAQ.  I saw twice in JPLAY forum.
 This is because MH-D003 accepts DoP up to DSD128, iFi micro iDSD up to DSD256.
 Phone applications using USB output are usually DoP and not DSD native.
 If you give DSD native DSD256 to MH-D003, then it works.


----------



## b0bb

Rebuilt the Amanero USB powersupply.
 The PS is based on the LT3042, this rebuild addressed a couple of issues particularly the use of conventional electrolytics at the output.
 The equivalent series inductance (ESL) and equivalent series resistance (ESR) of the original cap is far beyond the manufacturer specified limits.
  
 Before picture:
 The output cap is the brown one at the top center.

  
 After picture:

  
 The 470uF brown cap (ESR 60-80mOhm) replaced by a 330uF Kemet Tantalum polymer (ESR 4mOhm). 
 LT's ESR recommendation for output cap is <50mOhm.
 Ripple current, current rating increased from 2A -->8.3A
  
 Added bypass caps in the C4 and C5 positions, these are stacked caps to reduce ESL, made with TDK XR7 MLCC ceramic caps + Rubycon Acrylic film SMD caps.
 The big red cap is a 10uF WIMA film cap, the little cap in the C6 position is also 10uF, made very small to reduce ESL, a requirement in that part of the circuit.
  
 The rectifiers, the 4 TO220 packages near the blue wiring block, had exposed metal tabs at supply voltage, replaced with the fully insulated Vishay Schottky diodes.
 This have very low leakage and very low switching noise.
  
 Final change is the replacement of the Panasonic FC caps with OSCON SEPF polymer caps, this provides a very low impedance and high ripple supply.
  
 The LT3042 is a new design, its main advantage is the ability to keep working at high frequencies, it is still providing effective regulation and power supply rejection at 10MHz and above. Commonly used high performance regulators like the LT1963 stop working around 2MHz, the venerable LT317 quits around 200kHz.
 Noise is also very low around 0.8uVrms, much better that the 2 regulators mentioned.
  
 This is one of the main reasons for this rebuild, the original components were not up to the task of extracting maximum performance from the LT3042.
 One of the more economical rebuilds with <$30 in parts.
  
 The main benefit is to the Crystek XO driving the the Amandero, and power supply to the XOs is critical.
  
 The sound improvement is along the lines of using an external DDC, the soundstage deepens and there is an immediate improvement in transparency, at the same time the rendering of the transients like clashing cymbals is more defined.
  
 Sibilance common in the DS type DACs is also much reduced.
  
 The unexpected change is the improvement in the low bass, the bass notes hit lower but without muddying the midrange or introducing additional warmth.


----------



## -Felix-

b0bb, thanks for your interesting comments on the MH-DA003 and for sharing all the details about the modifications you tested.
  
 I have my MH-DA003 for a couple of weeks now and consider to install the same modifications. However, I have a few questions:
  
 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?
  
 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?
  
 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?
  
 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)?
  
 5) Could you please confirm, amend or correct this part list (including quantities):
  
 2x Ticha 994 from Sonic Imagery Labs
 2x NJR Muses01
 8x RNE1C471MDN1PX
 20x MBRF10H100-E3/45
 2x PHE426DJ5330FR17T0
 4x TX2575 249R00 0.05%
 8x WIMA polypropylene caps (part number?)
 2x Y006910K0000J0L
 3x TPS7A4700-Board (digital side only?)
 1x CCHD-950X-25-100.000
 2x 16SA47M? ("Sanyo OSCON-G" caps)
  
 I will try to buy most of the parts in Germany and found almost everything available from Mouser or Digi-Key. I can order the Ticha 994 from the US. For some other parts the shipping costs would be higher than the actual price. Therefore I would appreciate alternative recommendations where indicated.


----------



## 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

b0bb said:


> _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
> ...


 
  
 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

abartels said:


> 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

b0bb said:


> 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.
> 
> ...


 
  
 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

abartels said:


> 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

justbenice said:


> 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

justbenice said:


> 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

justbenice said:


> 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

justbenice said:


> 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.


----------



## justbenice

b0bb said:


> 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.


 
 Hi b0bb, Thank you so much for all the informations! I have some more questions and hope you can help!
  
  What is the difference between Sonic Imagery Labs  994Enh-Ticha LV Variant and 994Enh-Ticha ? What should i get ? And i am using RCA port only, so the Sonic Imagery opamp will goest to the unbalanced section, right?  Do i need to upgrade MUSE01 for the balanced section if i not using the XLR port?
  
  Yes my Amanero PS board use the DAC exit  transformer, so what transformer would you recommend for the Amanero PS board ? is this ok : *115V/230V 30W High Quality Audio R-Core Transformer 15V+15V 9V+9V For Preamp *(24USD in ebay, shipped from hongkong) *, *And can you post the pic of your DAC so i can  know how to add another transformer  to the DAC. 
  I will mod somethings to my DAC, but as I am not a professional, i will do only what doesn't touch the 4 layer board. So what do you think i should mod ?
  
 Thank you!


----------



## b0bb

justbenice said:


> What is the difference between Sonic Imagery Labs  994Enh-Ticha LV Variant and 994Enh-Ticha ? What should i get ? And i am using RCA port only, so the Sonic Imagery opamp will goest to the unbalanced section, right?  Do i need to upgrade MUSE01 for the balanced section if i not using the XLR port?
> 
> Thank you!


 
 The MUSES01 drives the RCA port, the Ticha is the I/V converter.
  
 994Enh-Ticha LV is for low voltage systems will not work in the LKS board get the 994Enh-Ticha


----------



## b0bb

justbenice said:


> Yes my Amanero PS board use the DAC exit  transformer, so what transformer would you recommend for the Amanero PS board ?


 
  I am using the Antek AN-0107 transformer.
  
 Antek sells on Ebay
 http://www.ebay.com/itm/252099760714
  
 I mount mine on the front right hand corner.

  
 Closeup of the Antek unit, I moved the front right foot and the bolt goes thru the transformer and metal foot.

  
 The red wires go to the mains, due care and caution must be taken when working with mains voltage.


----------



## justbenice

Hi b0bb, thank you a lot for your help. That Antek AN-0107 transformer cost 42usd to ship to my country so i will look for another transformer in ebay. I think R core will be my choice. Can you confirm that you are feeding 7v to the usb PS board ? Or 2x7v which is 14v total ?
 An can you list extacly all the part number you used for mod the Amanero power suply board in post #74 ?


----------



## b0bb

7V ac
The main caps are 1000uf oscons 16V
Output cap is 330uf Kemet Tantalum Polymer 10V

The SMD parts are best left for later they are mentioned in my original post.

Don't have the part numbers with me at the moment this is pretty common components on Mouser or Digikey


----------



## justbenice

Thank you b0bb for all the help. I'v ordered some part, hope everything will go well.
  
 I just looked again my Amenaro power board and just found out that LKS has change some thing in the board,not as same as your board anymore, i wonder if those change will effect the parts i order (1000uf oscons 16V and 330uf Kemet Tantalum Polymer 10V) ?


----------



## b0bb

justbenice said:


> i wonder if those change will effect the parts i order () ?


 
 Looks OK
 Swap out the existing caps for the 4x 1000uf oscons 16V and 1x 330uf Kemet Tantalum Polymer 10V (This is a surface mount part)


----------



## RogerWilco

Very interesting work!


----------



## justbenice

Due the very high shipping rate from digikey and mouser, i wonder anyone have spare  4x 1000uf oscons 16V and 1x 330uf Kemet Tantalum Polymer 10V that can share with me ? I will pay the shipping fee and the caps cost.


----------



## abartels

justbenice said:


> Due the very high shipping rate from digikey and mouser, i wonder anyone have spare  4x 1000uf oscons 16V and 1x 330uf Kemet Tantalum Polymer 10V that can share with me ? I will pay the shipping fee and the caps cost.


 
  
 Try ebay
 http://www.ebay.com/sch/i.html?_odkw=1000uf+oscon+16V&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xoscon+16V.TRS0&_nkw=oscon+16V&_sacat=0


----------



## justbenice

abartels said:


> Try ebay
> http://www.ebay.com/sch/i.html?_odkw=1000uf+oscon+16V&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xoscon+16V.TRS0&_nkw=oscon+16V&_sacat=0


 
 Thank you. I got the transformer in ebay, i found the 330uf Kemet Tantalum Polymer 10V but could not find the right 4x 1000uf oscons 16V


----------



## tribon

It is my first post on this fascinating forum.
 I would like say Thank You to b0bb for all the detailed descriptions in LKS topic.
 I'm owning this DAC for couple of months and I'm still amazed how good it is.
 But I have some questions about possible upgrades 
  
 Have you ever considered change of opamp to OPA301 ?
 http://www.ebay.com/itm/1X-OPA301-DUAL-AUDIOFEEL-Hi-End-Audio-DISCRETE-OP-AMP-Board-Low-Impedance-/271838130217
 Lately I was reeding positive comments about performance...
 It's easy change with possibility to go back to stock opamp.
  
 Second question is about stock Amanero card. I was thinking about powering PC USB card (PPA v2) with power bank. Do you think that it will eliminate need to change power supply inside LKS (upgrade board from LKS)? Amanero will get clean 5V from battery on USB cable...


----------



## b0bb

tribon said:


> Have you ever considered change of opamp to OPA301 ?
> http://www.ebay.com/itm/1X-OPA301-DUAL-AUDIOFEEL-Hi-End-Audio-DISCRETE-OP-AMP-Board-Low-Impedance-/271838130217
> Lately I was reeding positive comments about performance...
> It's easy change with possibility to go back to stock opamp.
> ...


 
 There is not enough information on the Audiofeel OPAmps, I generally like to see a full datasheet rather than a simplified marketing blurb.
  
 There is no mention of the Gain Bandwidth and closed loop bandwidth, needs at least 50MHz for the LKS to start performing.
  
 There is something odd about the specs, the output is current limited to ±30mA but the idle current is 54mA, 30mA output current is right on the limit.
 ES9018 output current in mono mode is 32mA.
  
 The other thing is the board is 44mm tall, the LKS has about 50mm clearance between the board and top of the case, take off 5mm for the socket and the Audiofeel will almost be touching the top of the case.
  
 The stock Amanero is bus powered, the PPA may bring some benefit. I used my stock Amanero card with the iFi iUSB Power but did not hear too much of a difference.
  
 The modified powersupply should only be used with the enhanced Volent/LKS USB interface, the one with the Crystek XOs.


----------



## b0bb

justbenice said:


> Thank you. I got the transformer in ebay, i found the 330uf Kemet Tantalum Polymer 10V but could not find the right 4x 1000uf oscons 16V


 

 You can subsitute with Panasonic FM caps
  
 Here is a link from Farnell
 http://uk.farnell.com/panasonic-electronic-components/eeufm1c102/cap-alu-elec-1000uf-16v-rad/dp/1219463
  
 If you can post a closeup of the markings on the blue caps on your unit, I might be able to identify them.


----------



## tribon

b0bb said:


> There is not enough information on the Audiofeel OPAmps, I generally like to see a full datasheet rather than a simplified marketing blurb.


 
  
 Thank you.
 It seams that you are using this opamp (2pcs)?
 http://www.ebay.com/itm/SonicImageryLabs-994Enh-Ticha-DUAL-Discrete-OpAmp-DIP8-performance-upgrade-/251471555181?hash=item3a8cdf6a6d
  
 What is your experience which change will be more beneficial for audio quality: Volent/LKS USB upgrade or opamp change?


----------



## b0bb

tribon said:


> What is your experience which change will be more beneficial for audio quality: Volent/LKS USB upgrade or opamp change?


 
 My recommendation is to swap out the opamp first it is the easiest and goes part of the way to address one of the most common complaints of the Sabre32, the overbright top end and the listening fatigue than can follow from that.


----------



## tribon

Thank you b0bb.


----------



## justbenice

b0bb said:


> You can subsitute with Panasonic FM caps
> 
> Here is a link from Farnell
> http://uk.farnell.com/panasonic-electronic-components/eeufm1c102/cap-alu-elec-1000uf-16v-rad/dp/1219463
> ...


 
 Dear Bobb,
  
 Please see my "blue caps"   :

  
  
  
  
  
 Could you see this ebay link :
  
 http://www.ebay.com/itm/2-circuit-nyuu-J-FET-input-high-quality-sound-HiFi-operation-amplifier-MUSES01-/201442863391?hash=item2ee6ee291f:g:5RsAAOSwVL1WEdXF
  
 I am gonna buy Muses01 from them. Do you think they are legit ? 
 The Muses01 quite expensive, do you know any another place have better price ? 
  
 And because i am not using pre-amp, just power amp so i need 5v trigger from the DAC to turn off the amp remotely. Do you think those i2s input port can have 5v so i can trigger on/off my amp? I do that with usb port in my  Oppo Bluray Player and it work great, wonder if i can do it in this DAC.
  
 Thank you so much !


----------



## b0bb

justbenice said:


> Dear Bobb,
> 
> Please see my "blue caps"   :
> 
> ...


 
 The Blue caps with the 150 KO printed on the sleeve are Vishay BC 150RMI caps.
 http://www.vishay.com/docs/28323/150rmi.pdf
  
 About the same ESR as the Panasonic caps, the Panasonic FMs have 50% more ripple current capability (3.2A vs 2A).
  
 You might want to leave them alone.
  
 Price sounds about right for the Muses01, beware the lower-price counterfeits coming out of the usual places, it is all too easy to print the Muses logo on a fake opamp.
  
 Check the I2S pins on the LKS with a voltmeter and see if that changes when you push the front panel switch, the I2S pinout is in the LKS manual, the DAC leaves portion of the digital input powered on in standby mode.


----------



## justbenice

b0bb said:


> The Blue caps with the 150 KO printed on the sleeve are Vishay BC 150RMI caps.
> http://www.vishay.com/docs/28323/150rmi.pdf
> 
> About the same ESR as the Panasonic caps, the Panasonic FMs have 50% more ripple current capability (3.2A vs 2A).
> ...


 
  
  Thank you b0bb !
  Last night i was gonna ordered a Ticha 994 from Sonic Imagery Labs but i found out that was 94$ plus shipping fee for ONE unit, and it become too expensive to me as more than 200$ for a pair.  Do you have any subsitute  for that Ticha 994enh ?
  About the muses01, have you ever tried to replace with the muses02?  I read in some Chinese forum they use muses02 more often than the muses01.


----------



## b0bb

You can experiment with the Muses02 vs the Muses01 it is not in a critical location.
  
 The Ticha994, on the other hand, is in the most critical location and I have not found a substitute for it, this is the critical but expensive component that transforms the LKS from the normal Delta-Sigma junk sound to something the rivals and exceeds some of the better R2R DACs out there.
  
 (In plain terms, the LKS can sound like crap as the I/V opamp runs out of steam trying to deal with the output current coming from 16 DACs on each channel)
  
 The LKS modified in this manner, produces soundstaging, rhythm, pace and slam and overall quality that equals and in some cases exceeds the much praised Schiit Yggdrasil.
  
 The Yggdrasil on some material can sound like a DS DAC compared to the modified LKS.
  
 I have the Yggdrasil and the LKS is smoother and, I dare say produces a more "analog" sound, the clarity and precise instrument placement is left intact.
 (You can hear the musicians moving around and perhaps farting like some have claimed on both of these DACs)
  
 If you have to choose, leave out the Muses and put the money towards the Ticha994. The Muses sounds worse than the default opamp in the I/V converter location.


----------



## justbenice

Thank you bobb, i will try to get those opamp then


----------



## tribon

b0bb, I noticed that in March post you mentioned that DSD 256 is working with Raspberry Pi 2
  
 "Hirez PCM DXD and DSD256 works as advertised, using it with Audirvana and the Raspberry Pi 2"
  
 How did you manage to convince Raspberry to play native DSD with LKS?
 I was testing moOde and Volumio and it seams that both are working with DSD 64 (LKS is reporting DSD on screen) but when playing DSD 256 there is only silence and "un-lock" or "PCM384K" on screen (depends on software and DoP settings).
 I have to say that I was able to play DSD 256 files with PC/Foobar.


----------



## b0bb

Bill of Materials for Amanero board powersupply mod per PM request from another member.

  
*TO220 Diodes: Vishay MBRF10H100-E3/45 Qty:4*
 http://www.mouser.com/ProductDetail/Vishay-Semiconductors/MBRF10H100-E3-45/?qs=sGAEpiMZZMtQ8nqTKtFS%2fJkHNs4hgXaDnS4NPJ13sko%3d
  
*Oscon 16V 1000uf 16SEPF1000M Qty:4*
 http://www.mouser.com/ProductDetail/Panasonic/16SEPF1000M/?qs=sGAEpiMZZMsIwzbKW1rlgZRRlI97jKasCG1BVDIrDtw%3d
  
*Kemet 330uf 10V Polymer Tantalum Qty:1*
 http://www.mouser.com/ProductDetail/Kemet/T530X337M010ATE004/?qs=sGAEpiMZZMtZ1n0r9vR22RUW7UikPrjokjMznnXmFd4%3d
  
*WIMA 10uF 50V MKS2 Qty:1*
 http://www.mouser.com/ProductDetail/WIMA/MKS2B051001N00JO00/?qs=sGAEpiMZZMv1cc3ydrPrF7l45uRd9dVhvGS3cHOkNOA%3d
  
*C6 is a stacked cap made with a 10uF MLCC ceramic and 1uF FILM cap*

*Panasonic ECP-U1C105MA5 1uF 16V Acrylic 1210 SMD Cap  Qty:1*
https://www.digikey.com/product-detail/en/ECP-U1C105MA5/PCF1132CT-ND/285459
  

*Taiyo Yuden EMK325B7106KNHT SMD CAP CERAMIC 10UF 16V X7R 1210   Qty:1*
https://www.digikey.com/product-search/en?vendor=0&keywords=587-3334-1-ND
  
*C5 is a stacked cap made with a 33uF MLCC ceramic and 4.7uF FILM Cap*

*Rubycon 16ST475MC14532 SMD CAP FILM 4.7UF 20% 16VDC 1812 Qty:1*
https://www.digikey.com/product-search/en?vendor=0&keywords=1189-1798-1-ND
  

*TDK CGA8P1X7R1C336M250KC SMD CAP CERAMIC 33UF 16V X7R 1812 Qty:1*
https://www.digikey.com/product-search/en?vendor=0&keywords=445-7912-1-ND


----------



## b0bb

tribon said:


> b0bb, I noticed that in March post you mentioned that DSD 256 is working with Raspberry Pi 2
> 
> "Hirez PCM DXD and DSD256 works as advertised, using it with Audirvana and the Raspberry Pi 2"
> 
> ...


 

 DSD on the RPi is via DSD-Over-PCM (DoP) and it tops out at DSD128.
 DoP passthru requires ALSA hardware passthru, how that is done is player specific, Squeezelite uses the following command _squeezelite-armv6hf  -o hw:Amanero_
  
 There are experimental patches for the RPi Linux kernel for native DSD that is not encapsulated in PCM and for DSD256 and above but nothing official


----------



## tribon

Thank you b0bb, I hope they will implement DSD256 in close future!
  
 Amanero upgrade boards are on the way to me. I was thinking about above mentioned parts swap but would like to use original spare 8V output in toroidal transformer. More details here: http://www.hiendy.com/hififorum/forum.php?mod=viewthread&tid=85552&extra=page%3D1&page=2 Is it good approach? It seams that you are using separate transformer.
  
 I can see that you are using MUSES01 on unbalanced side. Can you describe difference compared to original opamp?


----------



## justbenice

Hi bobb,
 Have u ever tried to swap a muse01 opamp in the unbalanced side to the Supreme Sound Burson Opamp ? I think if we already have a best opamp Ticha for i/v section, why don't we have better muse01 opamp in unbalanced side ?


----------



## b0bb

tribon said:


> Thank you b0bb, I hope they will implement DSD256 in close future!
> 
> Amanero upgrade boards are on the way to me. I was thinking about above mentioned parts swap but would like to use original spare 8V output in toroidal transformer. More details here: http://www.hiendy.com/hififorum/forum.php?mod=viewthread&tid=85552&extra=page%3D1&page=2 Is it good approach? It seams that you are using separate transformer.
> 
> I can see that you are using MUSES01 on unbalanced side. Can you describe difference compared to original opamp?


 
 The MUSES01 is much warmer than the original opamp, the original is a little cold and sterile sounding.


----------



## b0bb

justbenice said:


> Hi bobb,
> Have u ever tried to swap a muse01 opamp in the unbalanced side to the Supreme Sound Burson Opamp ? I think if we already have a best opamp Ticha for i/v section, why don't we have better muse01 opamp in unbalanced side ?


 

 Never tried the Burson, I pass on devices that are not fully specified.


----------



## justbenice

b0bb said:


> Never tried the Burson, I pass on devices that are not fully specified.


 
 You should try and tell us which is the best ! Heh .


----------



## justbenice

I got the R-core  10W transfromer today and i am gonna put it in my DAC like this :


----------



## justbenice

I got 2 Ticha 944 opamp today :
  

  
 Swap with a original op-amp but could not find any real different in sound, it even have more hissing when compare with the original op-amp. I don't know if because it need time to burn in or not.


----------



## abartels

justbenice said:


> I got 2 Ticha 944 opamp today :
> 
> 
> 
> Swap with a original op-amp but could not find any real different in sound, it even have more hissing when compare with the original op-amp. I don't know if because it need time to burn in or not.


 
  
 Every electronic component needs burn-in time. Let it play for 150 hours continuously and post your findings


----------



## b0bb

justbenice said:


> I got 2 Ticha 944 opamp today :
> 
> 
> 
> Swap with a original op-amp but could not find any real different in sound, it even have more hissing when compare with the original op-amp. I don't know if because it need time to burn in or not.


 
  
 The opamp is normally dead quiet, when it starts to hiss, something is off.
  
 Check the voltage between pins 2 and 3 of the XLR output connector, if it is greater than 10mV (0.01V), the DAC needs to be adjusted to reduce the offset to 0V, that is the purpose of the blue trimpots next to the DAC chip.
  
 Do not connect any equipment to the output while this measurement and adjustment is being done.
  
 Warm up the DAC for about 10 mins before making this measurement and must be power-cycled after the adjustment is done.
  
 Repeat for the other channel.


----------



## justbenice

b0bb said:


> The opamp is normally dead quiet, when it starts to hiss, something is off.
> 
> Check the voltage between pins 2 and 3 of the XLR output connector, if it is greater than 10mV (0.01V), the DAC needs to be adjusted to reduce the offset to 0V, that is the purpose of the blue trimpots next to the DAC chip.
> 
> ...


 
 Hi boob,
 Yes normally it dead quite. "Hissing" here i mean the treble is very thin and when it high it have ssss ssss like hissing.


----------



## abartels

justbenice said:


> Hi boob,
> Yes normally it dead quite. "Hissing" here i mean the treble is very thin and when it high it have ssss ssss like hissing.


 
  
 Seems little strange, this shouldn't happen, but, really, let it play continously for 1 week, if there's still a sharp edge around voices and "S-sounds" maybe you have to adapt circuitry.
 The version you bought, what's in it's design rules? What kind of decoupling does it need? Maybe ask the seller about this, very often they have other insights and can help solve problem!


----------



## abartels

Btw, is your whole "sound picture" thin, so midrange and bass, also thin? Or just SHARP highs?
  
 Could be some sort of oscillating, check decoupling (caps), or bad contacts - cables.


----------



## justbenice

abartels said:


> Btw, is your whole "sound picture" thin, so midrange and bass, also thin? Or just SHARP highs?
> 
> Could be some sort of oscillating, check decoupling (caps), or bad contacts - cables.


 
 Hi,
 Not all sound picture thin, the sound after swap to ticha opamp have more details, easier to listen. But only the treble become more ssss and thin. I see some improve today after 12 hours burnin. I will get back about this ticha opamp after arround 200hours burn-in
  
 For a spare transfomer of USB power board,i think this is must upgrade, sound improve alot after having spare transfromer for a usb power board.


----------



## b0bb

justbenice said:


> Hi boob,
> Yes normally it dead quite. "Hissing" here i mean the treble is very thin and when it high it have ssss ssss like hissing.


 

 That is the symptom that says offset adjustment is required.
 The adjustment sets the DAC common mode reference voltage which directly affects the sound quality.
 This reference voltage can change if the opamp is changed.


----------



## justbenice

b0bb said:


> That is the symptom that says offset adjustment is required.
> The adjustment sets the DAC common mode reference voltage which directly affects the sound quality.
> This reference voltage can change if the opamp is changed.


 
 Thank you. I will check the voltage between pins 2 and 3 of the XLR output connector like you asked. But this LKS DAC XLR output pin is normal way or reverse way ?
 And what i need to do is adjust those blue trimpot in this picture untill the volt of pin 2 and 3 of XLR output become 0v. Right ?


----------



## b0bb

justbenice said:


> Thank you. I will check the voltage between pins 2 and 3 of the XLR output connector like you asked. But this LKS DAC XLR output pin is normal way or reverse way ?
> And what i need to do is adjust those blue trimpot in this picture untill the volt of pin 2 and 3 of XLR output become 0v. Right ?


 
 Adjust the blue trimpots until the voltage difference between pins 2 and 3 is 10mv or less.


----------



## justbenice

Hi bobb,
  
 I 'v checked volt out between pin 2 and 3 of the XLR output and it all arround 5-7mV. After 2 days of burning in , the op-amp become better. I think the thin treble cause by very new op-amp and haven't enough burn in. I will wait arround 1 more week to see if it improve.


----------



## b0bb

justbenice said:


> Hi bobb,
> 
> I 'v checked volt out between pin 2 and 3 of the XLR output and it all arround 5-7mV. After 2 days of burning in , the op-amp become better. I think the thin treble cause by very new op-amp and haven't enough burn in. I will wait arround 1 more week to see if it improve.


 

 Give it about a month to completely settle in, keep it powered continuously.
 Both the opamp and the new USB interface takes time to settle in.
  
 It is quite easy to attribute transitional changes to an "improvement".


----------



## justbenice

Hi Bobb,
  
 Can you swap the Muse01 to the original opamp  to see if the treble become thin ? I wonder if the treble become thin because i don't have muse01 opanp.


----------



## b0bb

justbenice said:


> Hi Bobb,
> 
> Can you swap the Muse01 to the original opamp  to see if the treble become thin ? I wonder if the treble become thin because i don't have muse01 opanp.


 

 As mentioned on previous occasions the MUSES01 performs worse than the original stock LKS opamp in the I/V role , the sound stage is constricted and lacks depth.


----------



## justbenice

Hi, i meant can you swap the muse01 in RCA section back to original opamp to see if the treble got thin?


----------



## b0bb

justbenice said:


> Hi, i meant can you swap the muse01 in RCA section back to original opamp to see if the treble got thin?


 
 The MUSES01 in the RCA section makes it a little bit warmer and that is about all.
  
 LKS made a trade off in order to use the lower cost Crystek crystal and tried to adjust the I/V and filter section to compensate, changing the opamps undoes some of the compromises.
  
 I replaced the CCHD-575 with higher performing CCHD-950X. The 950X gets rid of the treble emphasis without losing the details and resolving capability of the DAC.
  
 If you can find an electronics shop that can remove the Crystal you might want to take a close look at what I have done.


----------



## tribon

> Originally Posted by *b0bb* /img/forum/go_quote.gif
> Check the voltage between pins 2 and 3 of the XLR output connector, if it is greater than 10mV (0.01V), the DAC needs to be adjusted to reduce the offset to 0V, that is the purpose of the blue trimpots next to the DAC chip.
> 
> Do not connect any equipment to the output while this measurement and adjustment is being done.
> ...


 
 1. This adjustment should be done when DAC is working - playing song without amplifier connected to XLR or RCA?
 Please confirm pin numbers on male connector:
 https://upload.wikimedia.org/wikipedia/commons/8/81/XLR_pinouts.svg
 When looking on LKS from the back it will be 2- right top pin and 3- bottom central pin?
 By "power cycling" you mean OFF and ON again?
  
 2. Today I'm going to replace amanero with outside powered board. You have mentioned that amanero in your LKS is connected by toroidal transformer to the mains. It means that amanero board is powered even when LKS is in stand-by mode?


----------



## justbenice

My LKS Amanero power board with a dedicated transfomer :


----------



## b0bb

tribon said:


> 1. This adjustment should be done when DAC is working - playing song without amplifier connected to XLR or RCA?
> Please confirm pin numbers on male connector:
> https://upload.wikimedia.org/wikipedia/commons/8/81/XLR_pinouts.svg
> When looking on LKS from the back it will be 2- right top pin and 3- bottom central pin?
> ...


 
 1.
 Make the adjustment without any music playing.
 The drawing of the connector + pinout http://www.neutrik.us/zoolu-website/media/download/1298/Drawing+NC3MAH-0
  
 Power cycle means turn off  the DAC and turning it back on.
  
 2.
 Amanero will be powered when DAC is in standby.


----------



## tribon

Thank you b0bb for all your help!
 I replaced amanero and now trying to fit additional transformer inside LKS. It was so good investment!
  
 I have now 2xOPA301 and 2xMuses01 on side but decided to postpone further tests/changes and listen to the music...


----------



## RogerWilco

Very nice work!


----------



## -Felix-

b0bb,
  
 your explanation in post #76 was very helpful, but I am still trying to figure out what exactly surrounds your Ticha 994 opamps. As far as I can tell from the pictures, you removed everything but the 100uF Panasonic FCs. On each side/channel, there is the new trimpot, the new yellow Vcom bypass 100uFcaps, the original 100uF Panasonic FC, two (?) empty resistor spots on the top side, two new TX2575 on the underside together with two new (additional ?) WIMA-caps on the underside. What else is new on the top side. On each side there are five parts directly around the opamp socket, which I cannot figure out. Two of them are supposedly the new 220pf Corning low-K CGW Glass Caps, which I missed the last time. What did you put in the other two spots on both sides of the opamp socket and what is the component at the head-end of the socket, bent horizontally and sticking out from under the Ticha? A close-up photo with the Ticha opamp removed would be very helpful. An explanation of these parts and the setup would also do.
  
 Btw, even though I was not actively working on this project in the last couple of weeks, I could already find some of the required parts. I started with the hard to find and overseas import parts. The Ticha 994 opamps, the TX2575 resistors, three TPS7A4700 boards, and the Sanyo OSCON-G caps are already sitting on my desk and waiting for the Christmas holidays to be put in the DAC. I found almost everything else in stock at Mouser or Digikey. The only remaining issues are the WIMA caps, the Corning low-K CGW Glass Caps, and whatever else unknown there needs to be put next the opamp socket. The WIMA caps are nowhere in stock and WIMA themselves have not responded to my sample inquiry yet. I found Cornell Dubilier CD15FD221FO3F mica caps in stock at mouser. Would they be a same quality equivalent for the Corning low-K CGW Glass Caps? Other suggestions?
  
  
  
 Quote:


b0bb said:


> _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
> ...


----------



## b0bb

-felix- said:


>


 

 The transparent caps around the I/V converter are polystyrene caps, they form part of the frequency shaping network for the DAC.
 Replacing the original WIMAs should only be done if you have access a LCR meter or bridge, I matched mine to better than 0.5%.
  
 The component bent 90 deg is also a polystyrene cap, it looks a little different because the electrode foils are made of copper rather than aluminium.
  
 The Corning CGWs shows up from time to time at reasonable prices such as this one www.ebay.com/itm/221942022774.
 The 200pF caps will work for this purpose
  
 Similarly the WIMAs can be found on Ebay for reasonable prices www.ebay.com/itm/161457997710


----------



## -Felix-

Thanks for the links and the explanation. I have no experience in matching components. Just found some threads here on head-fi and google. But it does not sound to hard given the right meter. However, 0.5% within these capacity ranges sounds challenging. I really need to think about the error margins of the meter and in the whole matching setup. What is the correct time to do the matching, brand new from the shelf or after some burn-in procedure? Do they just have to be matched in pairs or at the same time also match or relate to some other components? I am not sure I am going to do the matching...
  
 Assuming I skip the new transparent polystyrene caps, then the TX2575 (underside) would be in parallel to the original WIMA cap (top side) and the new WIMA cap (underside) would be in parallel to the new Corning CGW glass cap, correct?
  
 But as this is already a tricky part of double through the hole soldering, I think it is a now or never decision to put in the new transparent polystyrene caps. What audible difference do you expect? Do you expect it to be significant (correct matching assumed)?


----------



## tribon

justbenice, capacitors on new pcb board are very high (top left on your last picture). Didn't you have problem to close cover without shorting anything?


----------



## b0bb

> What audible difference do you expect? Do you expect it to be significant (correct matching assumed)?


 
  
 The polystyrene caps help to eliminate the harsh topend in the Sabre32 DAC.


----------



## -Felix-

b0bb said:


> The transparent caps around the I/V converter are polystyrene caps, they form part of the frequency shaping network for the DAC. [...]
> The component bent 90 deg is also a polystyrene cap, it looks a little different because the electrode foils are made of copper rather than aluminium.
> 
> The Corning CGWs shows up from time to time at reasonable prices such as this one www.ebay.com/itm/221942022774. The 200pF caps will work for this purpose
> ...


 
  
 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 MKP2*C*031501H00JSSD caps (63VDC/40VAC), but you posted a link to MKP2*D*031501H00JSSD 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)?


----------



## justbenice

tribon said:


> justbenice, capacitors on new pcb board are very high (top left on your last picture). Didn't you have problem to close cover without shorting anything?


 
 Hi
 Those cap are original caps. So it have to fit


----------



## tribon

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.


----------



## b0bb

-felix- said:


> 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?
> ...


 
 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

tribon said:


> 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

tribon said:


> 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

justbenice said:


> 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

tribon said:


> 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

justbenice said:


> 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-

b0bb said:


> [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

justbenice said:


> 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

-felix- said:


> 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

justbenice said:


> 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  :
> 
> 
> 
> ...


 
  
 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

gto88 said:


> 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?
> ...


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


----------



## gto88

Thanks for affirming it.
 And Have fun modifying it.


----------



## justbenice

b0bb said:


> 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.
> ...


 
  
 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

justbenice said:


> 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 ?
> ...


 

 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

justbenice said:


> 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

gto88 said:


> 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.
> ...


 
 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 ?


----------



## b0bb

Good to see you are getting the desired results.
 I also have the Schiit R2R Yggy and the modified LKS is equal to it and better than the Schiit in some areas.
  
 It runs very warm on mine. The big heatsinks run about 45degC the smaller ones ones about 50degC.
  
 Replacing the transistors will not change things, the heat is the waste energy due to the linear voltage regulator.
  
 If your the heatsinks on your DAC is higher than the number I am seeing, check the AC voltage going into the DAC is within ±10% of the nominal spec.


----------



## justbenice

b0bb said:


> Good to see you are getting the desired results.
> I also have the Schiit R2R Yggy and the modified LKS is equal to it and better than the Schiit in some areas.
> 
> It runs very warm on mine. The big heatsinks run about 45degC the smaller ones ones about 50degC.
> ...


 
 Thank you. Now i know why it getting hot, my AC voltage in the night going to over 230V.


----------



## justbenice

I got a pair of Supreme Sound Opamp V5 here, swaped it with my old Muses01 for a analog output stage. The sound is pretty good! I will tell more details about it after it completely burnin.


----------



## b0bb

justbenice said:


> I got a pair of Supreme Sound Opamp V5 here, swaped it with my old Muses01 for a analog output stage. The sound is pretty good! I will tell more details about it after it completely burnin.


 

 Once this is done burning in, a comparison between the Burson and the Sonic Imagery in the I/V converter position would be interesting.


----------



## justbenice

b0bb said:


> Once this is done burning in, a comparison between the Burson and the Sonic Imagery in the I/V converter position would be interesting.


 
 I want to compare it too. But Burson said it is not recommended for the I/V stage.


----------



## Adde01

Hi,
  
 I'm new to this forum and I just got my MH-DA003 yesterday with the upgraded USB board. I have been reading a lot about this DAC and I'm very happy that there are so many enthusiast who already made some great mods to this unit. I have a couple of questions:
  
 - I live in Sweden where we have 230v. The Antec AN-0107 only seems to work with 110v. Any recommendation of an equal transformer that I could use?
 - The Antec AN-0107 seems to have two 7v output. Should we use one or both outputs?
 - I only use the Balanced(XLR) outputs. Where should I put the pair of Ticha 994 and where should the pair of muse01?
 - Would it be better to use four Ticha 994?
  
  
 Thanks in advance
  
 Best regards
 /Adam


----------



## b0bb

adde01 said:


> Hi,
> 
> I'm new to this forum and I just got my MH-DA003 yesterday with the upgraded USB board. I have been reading a lot about this DAC and I'm very happy that there are so many enthusiast who already made some great mods to this unit. I have a couple of questions:
> 
> ...


 
  
 Welcome.
  
 The Antec has 2 primary windings, put them in series for 230v use, suggest you check with Antek to see if this is approved for use in Sweden.
 Connect the 2x7V secondary windings in parallel.
  
 If you are unsure, ask someone local with the required electronics knowledge for help, connection errors with power transformers can result in dangerous consequences.
  
 Talema makes a near equivalent Part #62030, Digikey sells it for 24 Euros.
 http://www.digikey.se/product-search/en?keywords=1295-1059-ND
  
 For balanced use, the Muses is not required, its part of the unbalanced analog filter chain.
 No benefit from 4xTichas for your balanced only application.
  
 If you are interested in an upgraded Ticha, there is a version with Vishay S-Foil output load resistors and TiN (Titanium Nitride) feedback resistors, it adds about 60% to the base cost.
 Check with Sonic Imagery to see if they still offer the upgraded version, this is the version I am using.


----------



## Adde01

Great thanks
  
  - Ok, I have contacted Sonic Imagery Labs about buying two: Model 994FC-Enh-Ticha
  - I have contacted Antec regarding the power transformer for 230v input
  - Which opamp should I replace on the board? There are four dip8 sockets. I don't know which is ised the the XLR output.
  
 Thanks


----------



## b0bb

adde01 said:


> - Which opamp should I replace on the board? There are four dip8 sockets. I don't know which is ised the the XLR output.


 
  
 The Ticha is the big green square one in the middle of the picture.


----------



## Adde01

Ok, and the two above I just live it with the original opamps right? I thought that the opamps that needed to be changed for the XLR ouput was the ones above. 
  
 One more question. Why is there a difference if we put in a seperate power transformer for the USB power supply? The power tranformer for that is already in the dac has two outputs where one is not used. Could you please explain the difference.
  
 This is what I got from Sonic Imagery Labs:
  
_The Model 992FC-Enh-Ticha single is a higher output current drive option _
_(150mA vs 175/200pk mA) and the 3 resistors in the audio path are _
_replaced with (1) TaN type in the internal comp and (2) Vishay Naked _
_Foil type in the drive stage. This option is special order and adds _
_$40.00 to the cost of the opamp. ($89.00 total/ qty 1-4 pcs)_
  
_The 994 is the DUAL opamp equivalent of the Model 992_
_The Model 994FC-Enh-Ticha DUAL is a higher output current drive option _
_and same components above replaced. This option is special order and _
_adds $80.00 to the cost of the opamp. ($174.00 total/ qty 1-4 pcs)_
  
 I also got a response from Antec. I just need to serial connect the AC input to get the 230v. Only one channel will be used to power the USB board. Could I use the other channel to make a 12v trigger out port? But that is only 7v so maybe I can use the standard power transformer to make the 12v trigger out. Will that be wrong? Or will that interfere with the sound quality?
  
 Thanks


----------



## b0bb

adde01 said:


> Ok, and the two above I just live it with the original opamps right? I thought that the opamps that needed to be changed for the XLR ouput was the ones above.
> 
> One more question. Why is there a difference if we put in a seperate power transformer for the USB power supply? The power tranformer for that is already in the dac has two outputs where one is not used. Could you please explain the difference.
> 
> ...


 

 The ES9018 has balanced output, the XLR balanced drive comes straight out of the current-voltage (I/V) convertor (the Tichas)
 The decision of changing the opamp for the unbalanced side is up to you, it is not needed for XLR operation.
  
 The USB interface on the LKS has a galvanic noise isolator, the enhanced USB board must be powered separately, if you reuse the the existing transformers, the noise from the computer will have a way to get into the DAC.
  
_994FC-Enh-Ticha DUAL  _is the best option, this has the widest range of Class-A operation of about 26-28mA, the ES9018's maximum current output is 32mA, the I/V convertor operates in Class-A mode about 88% of the time. (The numbers for max load current the manufacturer quotes is for Class AB mode, this mode is not good if you are after a good sounding DAC)
  
 You have to use both secondary 7V windings for the USB board, a single winding may not supply enough power to keep the board stable, the board might continue to work but the performance of the Crystek Femtoclocks will be affected.
  
 Use a power sensing strip with an adjustable trigger and plug in a 12V wallwart or transformer for the 12V trigger.
 http://www.amazon.com/Smart-Strip-SCG4-Autoswitching-Technology/dp/B000L9A7ZS/ref=sr_1_9?s=electronics&ie=UTF8&qid=1458296327&sr=1-9&keywords=smart+power+strip


----------



## Adde01

Hi,
  
 Thanks for your answer. 
  
 - You was right about the Antec AN-0107. Just needed to serial connect the AC input. The I will parallell connect the 7v output to make sure I get enough current
 - I will order a pair of 994 FC for the I/V stage. 
 - I would like to change the clock but the one you recommend seems to have a different size. Will it fit?
  
 Thanks


----------



## b0bb

adde01 said:


> - I would like to change the clock but the one you recommend seems to have a different size. Will it fit?


 
  
 The bigger Crystek will fit the pads on the  PCB.
  
 There is also a thru-hole mounting on the board, these are the 4 holes drilled around the stock crystal.
  
 The footprint is a 14-pin dip socket, all the pins except the 4 on the corners are removed, the XO can be put onto an adapter and plugged in.
 Twisted Pear sell them
 http://www.twistedpearaudio.com/digital/cronus.aspx
  
 Scroll down to the bottom of the pace, $USD 8.50 at the time of writing


----------



## justbenice

Nice instructor B0bb, the hardest part when i modded my LKS 003 is solder out the old small Crystek  Clock and solder  in the bigger clock. I wish i known the clock  mounting board that time.


----------



## b0bb

A couple of photos of the Crystek mounted on the adapter.

  
 The other side

  
 Dip socket for the Crystal
http://www.mouser.se/search/ProductDetail.aspx?R=0virtualkey0virtualkey1108800


----------



## otec

Hi
  
 I would like to connect my Breeze Audio XMOS U8 via I2S (RJ45) to MH-DA003.
  
 As I understand DAC expects +3.3V DSD/ 0V PCM signal on Pin 7.
  
 But XMOS U8 uses Pin 7 for MCLK.
  
 Is there anyway to connect those together ? 
  
 Or is it better to use AES/EBU cable ?


----------



## b0bb

otec said:


> Hi
> 
> I would like to connect my Breeze Audio XMOS U8 via I2S (RJ45) to MH-DA003.
> 
> ...


 
  
 On the LKS End of the cable:
 Connect Pin 7 to Pin 8
  
 One the Breeze End of the cable:
 Leave Pin7 unconnected. MCLK is not required, the DAC reclocks the incoming bitstream.
  
 Give AES/EBU a try, you might like it better, the I2S inputs on the LKS do not have galvanic signal isolation this makes the DAC performance dependent on the source of the signal
  
 DSD via I2S is not officially supported on the LKS if you use the Breeze, it does not have a way to tell the DAC this is a DSD and not PCM stream.
  
 DSD is officially supported on the USB interface, anything else is up to the user to experiment.


----------



## otec

b0bb said:


> On the LKS End of the cable:
> Connect Pin 7 to Pin 8
> 
> One the Breeze End of the cable:
> ...


 
  
 Thank you! Very informative.
  
 I already use LKS USB input to stream from a different device.
  
 Breeze acts as a second input to DAC basically.
  
  
 Is it possible to transfer DSD via AES/EBU cable ?
  

 Also, is it better to use optical or AES/EBU input ? I read somewhere that optical can have a limit 192khz.


----------



## b0bb

This non-descript looking crystal XO is the next step in the mod, made by Abracon model # AOCJY1.
  

  
  
 About twice as tall as the Crystek that I was using previously.

  
 What is special about this one?
  
 The part number gives this clue to its purpose A*OC*JY1
  
 The *OC* here means *O*ven *C*ontrolled or in the long hand description Oven Controlled Crystal Oscillator --> OCXO
  
 The part contains a tiny oven to keep the temperature of the crystal stable, the metal case is about 55degC when it is running, the aim is to keep the XO output as stable as possible over time and temperature changes.
  
 The part is a low power and low cost OCXO, consumes about 330mA in steady state, this is within the 500mA limit of the LT1763 on the LKS motherboard.
  
 More importantly this is classified as COTS (Commercial Off The Shelf) and not dual use which means Digikey/Mouser can sell it countries outside the US.
  
 I was looking for an OCXO I can drop into the LKS without making too many compromises and I did not want an XO taking up a large amount of space inside the DAC, the big ones consume too much power (like the surplus Rubidium ones on Ebay)
  
 Specs wise, the close-in phase noise (stuff at 1kHz and below) is about the same as the Crystek it replaces.
 However as the following listening impressions show the engineering specs do not adequately measure the behavior in this kind of usage meaning Audio DACs.
  
 This part is most commonly found in satellite receivers and portable mobile celltowers.
  
*Listening impressions and burn-in progress*
  
 This is a long exercise, Abracon's specs only come into effect after minimum 30days of operation.
 I am using the SR009, HD800 and LCD3F.
  
 The headphone amps for the dynamic cans are custom, and the STAX uses the SRM-727
  
 As a SQ reference baseline I am comparing it to the Schiit Yggdrasil.
  
First 3 hours:
 This set the stage of everything to follow, main impressions are a significant improvement in the soundstaging and placement of voices within that soundstage.
  
 Treble and upper midrange has a hard etched character which caused listening fatigue. The Yggdrasil in contrast has a more rounded midrange and the voices came across as more real. The LKS seemed to have a nasal like quality.
  
 Detail retrieval was quite an improvement, the Yggy seemed downright muddy.
 I think this is also an artifact of hearing as I find my hearing tries to adapt to the two extremes, the OCXO performance at this stage is very raw, bright and aggressive.
  
  
72hours on:
  
 The initial treble hardness is gone, midrange has taken on an organic liquid character on the LCD3 and the SR003.
 HD800 shows a treble emphasis.
  
 The OCXO has been stabilized sufficiently to get individual impressions from the headphones.
  
 SR009:
 Overall very wide soundstage, the SR009 was completely transparent.
 Main item of note was a greatly enhanced bass response, it can be heard and felt, this is unusual for an electrostatic can.
 Effect was less obvious with the Crystek, the Yggy was hard hitting as usual but the physical visceral impact was greater on the LKS with the OCXO.
  
 LCD3:
 The sound stage was greatly enhanced a veil on the upper midrange was lifted. Dynamics started to improve as did the bass slam.
 The  onething I noticed with the LCD3 is the much smaller soundstage compared to the other 2 cans.
  
 This is starting to change with the OCXO mod, the LCD3 is becoming wider deeper and more detailed in its music presentation.
 I am seeing bigger changes with the LCD3 than with the other 2 as the hours roll on.
  
 HD800:
 The effect seen on the LCD3 was taken a step further, the HD800 completely disappeared and there were numerous occasions I had forgotten I was still wearing it.
 The upper frequency response was very well controlled as the HD800 show no signs of sibilance, this means the phase response/performance was greatly improved over the Crysteks.
 On Cymbal crash and taps on the hi-hat on  drum set , sibilance was detectable with the Crysteks but not on the Abracon OCXO
 The bass response was the most notable feature, HD800 bass is not know to be hard-hitting compared to the LCD3, with the OCXO the bass can actually be felt against the skull.
  
 Upper-midrange emphasis is evident but not as strident as in the initial couple of hours.
  
5 days:
 The XO has been baking in its oven for about 5 days now.
  
 HD800:
 All the top end glare is gone, no longer cringe everytime Taylor Swift or her instruments hits the high notes.
 The intensity of the music and the intimacy seems to have racked up a notch with superb pacing and rythm as expected from the HD800.
 Close miked tracks like on Tommy Emmanuel's Center Stage conveys the impression of "being there", previously there was a detached observer's feeling when listening to the same tracks.
  
 The close-in intimacy was previous lacking on the LKS, something the Yggy is very good at.
  
 LCD3:
 Bass response seems to have improved, going down by about half and octave.
 Brass slam and transients have surprised me, on tracks I thought I knew had me surprised a few times and example is some of the opening bass lines in Christina Perri's Head and Heart Album.
  
 The big improvement was the LCD3 was able to completely disappear, all I get now is a wide soundstage, the previous veil with the LKS was also lifted.
  
 SR009:
 Skipping this one for now, the SRM727 takes too long to warm up and I do not leave the ES amp powered on 24x7
 Probably will swing back to the STAX over the weekend.


----------



## b0bb

otec said:


> Is it possible to transfer DSD via AES/EBU cable ?
> 
> 
> Also, is it better to use optical or AES/EBU input ? I read somewhere that optical can have a limit 192khz.


 
 Try it and see what happens, turn down the volume on the amp , it does not work you will get a burst of white noise.
 The manual does not mention DSD support.
  
 SPDIF optical is only officially specified to 96kHz, LKS is vague as to whether they support 192kHz over optical.
 (Similarly they claim DSD support over I2S but it only works if the DDC can toggle the DSDOE line (pin7))


----------



## otec

Got it, Thanks!


----------



## b0bb

Updated OCXO listening impressions at the 5day mark.


----------



## ferdy777

```
[color=rgb(33, 33, 33)] ops double post sorry![/color]
```


----------



## ferdy777

hello guys , I joined the forum to ask for advice .... I also possess the dac mh - da003 and I can not connect it to the interface usb gustard u12 with hdmi cable for i2s signal. work incorrectly DSD files . someone has the same problem and managed to solve? thank you


----------



## b0bb

ferdy777 said:


> hello guys , I joined the forum to ask for advice .... I also possess the dac mh - da003 and I can not connect it to the interface usb gustard u12 with hdmi cable for i2s signal. work incorrectly DSD files . someone has the same problem and managed to solve? thank you


 

 The DSD enable signal on the LKS HDMI is _*pin14*_


 On the Gustard this is _*pin15*_
 http://www.head-fi.org/t/752522/gustard-amplifiers-and-dacs/15#post_11341197
  
 The HDMI cable needs to be modified.
  
 If PCM via HDMI from the Gustard is not working you have other problems.


----------



## ferdy777

thanks B0bb, now i make a cable hdmi with pin 14 (lks part) connected to pin 15 (gustard U12)


----------



## Adde01

Hi B0bb,
  
 Could you please write down the more simpler mods that I could do to make the dac sound more like a R2R dac? I don't know anybody who is an expert on soldering the Crystal but other easier things he can do.
  
 I have done the following:
  
 - Ordered two 994FC
 - Bought the upgraded USB board
 - Ordered the Antec AN-0107 transformer
  
 Things to do:
 - Will remove the on/off switch
 - Will twist all the ac wiring to the transformer
 - Remove the bolts going through both transformers 
  
 Thanks in advance
  
 Best regards


----------



## b0bb

adde01 said:


> Hi B0bb,
> 
> Could you please write down the more simpler mods that I could do to make the dac sound more like a R2R dac? I don't know anybody who is an expert on soldering the Crystal but other easier things he can do.
> 
> ...


 
  
 The LKS itself needs about 30days to burn from new, suggest you do not try to modify it in that time as the sound will be constantly changing.
  
 The op-amps need about 30days of continuous operation to completely settle in.
  
 USB interface takes about 1-1.5 weeks to burn in.
  
  
 Once you are done, take a look at replacing the caps around the XO and the DAC
 The I/V resistor will also produce quite a large improvement and is fairly easy to remove
  
 The big list of the items is here
 http://www.head-fi.org/t/745032/lks-audio-mh-da003/30#post_11689879


----------



## Adde01

Hi,
  
 I'm a little bit confused regarding the 994 and the 994 FC. Please look at the response I got from Sonic Imagery Labs:
  
_Hi Adam_
_I am very familar with the LKS MHDA003 DAC. LKS Audio buys our units for there special order customers/dealers. This unit typically uses 4 of the Sonic Imagery Labs 994Enh-Ticha opamps. Two are in the DAC I/V stage and 2 are used in the Line Stage. Most users prefer upgrading the IV stage only. The 994Enh-Ticha FC Option would be most suited for the Line stage and the standard unit would be best suited for the IV stage as this stage does not require high current drive output. The DA003 revision of the LKS DAC requires either 2 right angle adapters or an additional DIP SOCKETS to fit all 4 opamps, as the manufacturer placed the opamps kinda close together. The earlier revisions did not need adapters._
  
_What is the difference between the upgraded and standard 994?_
  
_The Model 994Enh-Ticha FC Option DUAL is a higher output current drive option (150mA vs 175/200pk mA) and the 3 resistors in the audio path of each opamp are replaced with (1) Vishay TaN type in the internal comp and (2) Vishay Naked Foil type in the drive stage. This option is special order and adds_
_$80.00 to the cost of the opamp. ($174.00 each unit/qty 1-4 pcs)_
  
_Standard Model 994Enh-Ticha uses SUSUMI audio grade resistors in the audio path as standard. ($90.00 each unit/qty 1-4 pcs)_
  
_As both the 994 and its FC option far and away exceed the performance of any opamps by Burson, Dexa, Audio-GD or Spakolabs by orders of magnitude in some cases, my feeling is there is little to be gained by the purchase of the FC Option for the line stage of the DAC unless you are driving 25-100 foot long cables to get to your amp. This is where this option would be ideally suited._
  
  The IV stage is closest to the ESS DAC.
 The line stage is closest to the rear panel.
  
 The line stage drives both the balanced XLR and unbalanced RCA output.

  
_Hope this helps,_
  
_Richard Doporto_
_Sonic Imagery Labs_
  
  
 According to Richard the 994 FC is recommended on the line stage where the standard 994 is recommended on the I/V stage. He also says that both XLR and the RCA are using the line stage.
  
 Could you please help me out here so that I don't order the wrong parts.
  
 Best regards
 /Adam


----------



## b0bb

adde01 said:


> Hi,
> 
> I'm a little bit confused regarding the 994 and the 994 FC. Please look at the response I got from Sonic Imagery Labs:
> 
> ...


 
  
 I bought the 994FC for the enhanced Vishay metal foil resistors, the extra current output was just a bonus. I mentioned it as an option they had. The Vishays are $20-25 each and there are 2 of them on each half, so the quoted price is fair if you include the labour to install them.
  
 Now if Sonic Imagery also increased the bias to the output stage to have Class-A operation beyond 32mA load current it might be worth the extra, if you have no interest in the Vishays.
 16mA is Class-A bias current for the ES9018 I/V opamp to operate in full Class-A mode on the LKS.
  
 Here is mine. The Vishays are just barely visible between the PCBs.

  
 The XLR output follows the ESS reference design, schematic from HiFiDuino.
 https://hifiduino.files.wordpress.com/2013/08/es9018iv.png

  
  
 The U2 and U3 opamps on the left are the I/Vs note they go straight thru bypassing the buffer.
 LKS implemented the single-ended buffer slightly differently.
  
 U1 can be removed, the XLR will continue to work.

  
  
 The XLR out on the DAC as pictured works and there is no change in the sound or volume level.
 The XLR output copper trace is visible coming out  the left opamp in the centre of the picture, it goes to the 3 polystyrene caps correspond to C9, C10 and C11 on the schematic bypassing the other opamp.


----------



## Adde01

Thanks for your reply. So basically I don't need to change anything except the I/V stage with the 994 FC. So what Robert is saying:
  
 - Put 994 FC in the line stage is wrong?
 - The line stage affects the XLR is wrong
  
 Why do people change all four then? Do people use both the XLR and the RCA? 
  
 So in your opinion I should but the 994FC for the I/V stage and leave the standard opamps for the line stage IF I ONLY USE THE XLR output that is
  
 Thanks in advance
  
 Best regards
 /Adam


----------



## b0bb

adde01 said:


> Thanks for your reply. So basically I don't need to change anything except the I/V stage with the 994 FC. So what Robert is saying:
> 
> - Put 994 FC in the line stage is wrong?
> - The line stage affects the XLR is wrong
> ...


 

 There are no absolutes as there is always more than one way to get the same thing done, including leaving in the stock opamp. I think you will see an improvement but others have also run into problems as this thread shows, nothing that cannot be fixed.
  
 You can install the 994 in the line stage, nothing wrong or incorrect about that, you were interested in XLR only so it is your choice if you want to spend the money on the RCA interface.
  
 I use both XLR and RCA at the same time connected to different headphones.
  
 The 994 or 994FC will work in the I/V position, it is only drop in replacement that comes close to handling the current output of the 9018 in Class-A mode, for the RCA side there are plenty of options as you are not pushing 32mA of current thru the opamp.


----------



## Adde01

Ok, 
  
 Then I will buy a pair of 994 FC for the I/V stage. What is you recommendation for the line stage? Should I leave the stock or should be upgrade the stock to something else? What do you mean that people ran into problems?


----------



## b0bb

adde01 said:


> Ok,
> 
> Then I will buy a pair of 994 FC for the I/V stage. What is you recommendation for the line stage? Should I leave the stock or should be upgrade the stock to something else? What do you mean that people ran into problems?


 

 I would leave the the RCA side stock for now. The tall red boxes on my dac are Burson V5s, I am burning them in, quite a step up from the stock, a little better than the NJR MUSES01
  
 The stock XO is bright sounding and the 994 can worsen the situation, justbenice ran into this and found the sound was very thin.
 The stock XO is cheap about $25-35 USD at Mouser, don't worry if you damage it while extracting it.
  
 To avoid this, get a baseline of the DAC in stock form first, if you find it too bright out of the box, the analog filter caps may have to be changed first, the WIMA polyproplylene caps can be cold sounding, the Vishay schottky rectifier diodes will smoothen out the sound but it is a big job as there are 20 of them, 24 counting the USB interface.
  
 The Vishay diodes do a great job at keeping the rectifier switching noise very low.
  
 Installing the enhanced USB interface first is also a good first option, it is readily reversible.


----------



## Adde01

Ok, thanks.
  
 I will order two of the 994 FC and put in the I/V stage. 
  
 What does XO mean? 
  
 What mods do you recommend for the USB interface? I have the upgraded one.
 Are the mods to the USB interface simple/easy to do?


----------



## b0bb

adde01 said:


> Ok, thanks.
> 
> I will order two of the 994 FC and put in the I/V stage.
> 
> ...


 

 The XO is the Crystal Oscillator, the Crystek CCHD-575.
  
 The USB mods were to the Power Supply, quite straightfoward component swapping and cheap <30 $USD
 http://www.head-fi.org/t/745032/lks-audio-mh-da003/60#post_11913960


----------



## otec

Successfully connected Odroid C2 via i2s to DAC. Just grounded DSD/PCM pin. 

Sent from my Nexus 6P using Tapatalk


----------



## b0bb

otec said:


> Successfully connected Odroid C2 via i2s to DAC. Just grounded DSD/PCM pin.
> 
> Sent from my Nexus 6P using Tapatalk


 

 Glad you got it working and welcome to the club.


----------



## b0bb

This is the Supreme Sound V5 dual opamp review sample kindly provided by Supreme Sound, Burson's DIY arm.
 http://www.bursonaudio.com/products/supreme-sound-opamp-v5/

  
 Nicely made package with removable opamp adapter.

  
 I am using it in the unbalanced side of the LKS.

  

  
 The package is quite tall but fits inside the LKS, if the adapter is removed.
 No fitment problems overall

  
 I was using the NJR MUSES01 opamp previously and will be the basis of the comparison.
  
*Sound Impressions and testing.*
 The Burson Opamp is a lot cleaner sounding than the MUSES01, a little cooler and analytical.
 Instruments on the Burson was a lot more clearly defined and the placement in the soundstage is pinpoint accurate
 The MUSES appears at first to be a warmer sound which makes the music more intimate especially on closely miked tracks.
  
  
 However this is quite misleading, and I initially thought the MUSES was the sweeter sounding device.
  
 I decided do an ABX test to see if I can tell the opamps apart.
  
 The headphone amp I used is the Yulong A28 has a switchable input between balanced and unbalanced input, more importantly the unit was modified with 0.1% resistors in the gain path such that the output is exactly the same irregardless of the source.
  
 The output of the LKS for balanced and unbalanced connection is spot on as levels is concerned.
  
 The Yulong will switch without any audible noise so it is impossible to tell which is the source.
  
 This is my rebuilt A28, the big red switch at the rear panel is the input selector

  
  
 On the LKS the balanced input is straight thru to the output and the unbalanced output buffers and combines the balanced output.
 This is convenient for this test as clearly isolated the contribution of the opamp under test.
  
 I could always tell the the MUSES was in circuit the sound become slightly veiled and some clarity is lost.
  
 The Burson however was transparent unless one was extremely familiar with the track and looked for specific cues, I could not tell the difference between the balanced and unbalanced input.
  
 This _*near complete transparency*_ is what I look for, the opamp not interfering or altering or "enhancing" the sound.
  
 Performance of this opamp will degrade if it is asked to drive very long cables, it did not have any problems driving 6ft of my Gotham GAC-1 PROs which have a highish capacitance of about 180pF.
 (The Gothams have a wideband RFI and EMI shield, kills a lot of opamps trying to drive it.)
  
  
 Quite pleased with it overall, a distinct improvement from the MUSES01.
 I am thinking of buying a pair for myself.


----------



## b0bb

*DPLL (Digital Phase Locked Loop) Bandwidth Setting*
  
  
 Just tried changing the DPLL bandwidth to LBW, this is the second lowest setting that still has sound.
  
 I hear a slight improvement in the midrange and better midbass with PCM, DSD seems to have benefitted the most, less thin sounding on the higher frequencies.
 The LKS manual also mentions improving the sound quality by reducing the DPLL bandwidth.
  
 This seems to only work well with the Enhanced USB interface with the Crystek clock, it worsened the sound if used with the base Amanero card which sometimes drops out.
  
 LLBW is the lowest setting and sometimes fails with DSD2x or higher, so anyone experimenting with speakers should do this with the volume turned down as there is a nasty spray of noise when the DPLL loses lock.
  
 I am thinking the Amanero card has increasing jitter at the output as the sample rate is increased, the wider the DPLL bandwidth the higher the jitter tolerance.


----------



## ferdy777

b0bb said:


> The DSD enable signal on the LKS HDMI is _*pin14*_
> 
> 
> On the Gustard this is _*pin15*_
> ...


 
 Hi B0bb, i completed a custom hdmi with the change (pin 14 and 15). The dsd signal is now recognized by dac but the left and right channels are reversed . The phase is correct . With PCM file the channels and phase are OK. what can I do for your opinion? thank you


----------



## b0bb

ferdy777 said:


> Hi B0bb, i completed a custom hdmi with the change (pin 14 and 15). The dsd signal is now recognized by dac but the left and right channels are reversed . The phase is correct . With PCM file the channels and phase are OK. what can I do for your opinion? thank you


 

 The format of the data payload on the I2S output for the Gustard is proprietary to them, you are not the first to run into this.
  
 http://www.head-fi.org/t/780385/gustard-x20-dac/540#post_12453355


----------



## ferdy777

b0bb said:


> New USB interface from LKS. This is a modified Amanero USB interface using the Crystek CCHD957 low jitter clocks and ultra-low noise regulators.
> 
> This is what I was hoping Amanero would have offered from day one, no software change as it still looks like the Amanero interface to the host computer.
> I got this from Volent in Hong Kong.
> ...


 
 Ok B0bb, now i will buy this kit but i'm not able to find it. where can i buy? thanks.


----------



## b0bb

ferdy777 said:


> Ok B0bb, now i will buy this kit but i'm not able to find it. where can i buy? thanks.


 

 Contact Volent directly. http://www.volent.com.hk
 PM me for additional details.


----------



## sergemur

otec said:


> Successfully connected Odroid C2 via i2s to DAC. Just grounded DSD/PCM pin.




Hi! Can you spend some time to explain how it could be done? What soft do you use to stream audio from Odroid to DAC?

Thank you!


----------



## 0t73r

Hello.

I have some issue with my DAC where it doesn't turn on after few hours on standby (red ring).

Just wondering if anyone have this issue? Is there a way to fix this.
Thanks for your time.


----------



## b0bb

0t73r said:


> Hello.
> 
> I have some issue with my DAC where it doesn't turn on after few hours on standby (red ring).
> 
> ...


 

 Did this problem happen when you first got the DAC?


----------



## 0t73r

Yes when I first bought it. Its a small issue just wondering If it can be fix DIY.


----------



## b0bb

0t73r said:


> Yes when I first bought it. Its a small issue just wondering If it can be fix DIY.


 

 If you have a multimeter, a simple check would be the power supply voltages on the digital side of the dac, these are 3 regulators on the right hand side if you look at the DAC with the front panel facing you.
  
 Take measurement when it is running correctly and when it is misbehaving


----------



## jose1

Hello bObb,
Could you give me the exact references of OCXOAbracon AOCJY1, since there are 3 of them whichare similar and I do not know which to order.
Thank you


----------



## b0bb

jose1 said:


> Hello bObb,
> Could you give me the exact references of OCXOAbracon AOCJY1, since there are 3 of them whichare similar and I do not know which to order.
> Thank you


 
  
 You can get it either at mouser or digikey
  
 http://www.mouser.com/ProductDetail/ABRACON/AOCJY1-100000MHz/?qs=sGAEpiMZZMsC2cQJVRBSBUVTnCXPHX6IDcln7PotGtA%3d
 http://www.digikey.com/product-detail/en/AOCJY1-100.000MHZ/535-10656-ND/2441422


----------



## jose1

Thank You, b0bb


----------



## b0bb

I made an insulating boot for the OCXO to reduce the heat loss.
 The OCXO consumes 300mA when running, this places stress on the LT1763 regulator and the one further upstream.
  
 Reducing the heat loss reduces the heater power required to maintain the required 55degC operating temperature.
  

  
 I added heat reflective foil to the inside of the boot to reflect heat back into the XO, with this arrangement the outside of the boot is between 30degC and 35degC.
 Inside temp is 55degC.
  
 This is a good enough start and took me about 1hour to make. I will move to a better insulating material like styrofoam soon.
  
 Here is what it looks like mounted on the XO.
  
 Top view

  
 3/4 view

  
 Side view

  
 Initial prep, socket with XO removed.

  
 Add heat reflective foil to bottom of XO socket and add kapton tape to tie down XO

  
 XO wrapped in kapton heat insulating tape.


----------



## b0bb

After about an hour of warm up the, LT1763 voltage regulator supplying the OCXO is running at 37.5degC so the thermal stress is much reduced.
  
 I also moved the thermal boot up a little to allow for some air circulation around the LT1763.


----------



## jose1

Ok b0bb understood well.

Thank you


----------



## abartels

b0bb said:


> I made an insulating boot for the OCXO to reduce the heat loss.
> The OCXO consumes 300mA when running, this places stress on the LT1763 regulator and the one further upstream.
> 
> Reducing the heat loss reduces the heater power required to maintain the required 55degC operating temperature.
> ...


 
  
 +1
  
 Very well done B0bb!
  
 Nice project 
	

	
	
		
		

		
			




  
 Was there a special reason you selected the Abacron OCXO's? Do they have good reviews, or "just" bought them because of their specs?
  
 I'm waiting for Ian's stuff to arrive, and probably will try OCXO's too on the Dual Clockboard II. Those Abacrons are not very expensive!
  
  
 Regards,
  
 Alex


----------



## b0bb

abartels said:


> +1
> 
> Very well done B0bb!
> 
> ...


 

 Thanks.
  
 This OCXO is a low cost device as it started out as an experiment, specs are slightly worse on paper compared to the CCHD575 that comes stock with the LKS.
  
 On this dac, the imaging, pace and rythm is hands down better with the OCXO.


----------



## jose1

Hello b0bb

Before buying one or the other, could you tell uswhich are the best for LKS MH-DA003:

The CCHD575, the CCHD-950 X or the OCXO

Cordially

Jose


----------



## b0bb

jose1 said:


> Hello b0bb
> 
> Before buying one or the other, could you tell uswhich are the best for LKS MH-DA003:
> 
> ...


 

 CCHD575 comes with the LKS, I find this makes the dac bright sounding, CCHD950X is more balanced and this is the one I have been using for about 1year
  
 I like the OCXO better but it is still very new (<30 days), it is in a different class compared to the other XOs.
  
 It is down to personal choices, the OCXO is about 1.5X the cost of the CCHD950X + Adapter


----------



## jose1

Thank you.


----------



## DaaDaa

Guys im thinking of upgrading the opamps and im gonna get either Sparko or Sonic Imagery. the problem is I dont know what is the difference betwen the dual ones that have two pcb mounted on top of each other and sngle ones. are both compatible? what is the difference between them?


----------



## b0bb

dadbeh said:


> Guys im thinking of upgrading the opamps and im gonna get either Sparko or Sonic Imagery. the problem is I dont know what is the difference betwen the dual ones that have two pcb mounted on top of each other and sngle ones. are both compatible? what is the difference between them?


 

 The required opamps are the dual opamp, these are the ones with the dual PCB, if in doubt check with the manufacturer.


----------



## DaaDaa

b0bb said:


> The required opamps are the dual opamp, these are the ones with the dual PCB, if in doubt check with the manufacturer.


 
 I have ordered the new Burson V5i (x4) and the venerable LME49860 (x4) to roll. right now my LKA DA003 has 4 OPA1612 in the output. so ill be replacing all 4 and listening.


----------



## -Felix-

b0bb said:


> On the LKS End of the cable:
> Connect Pin 7 to Pin 8
> 
> One the Breeze End of the cable:
> ...


 
  
 Hi,
  
 I was away from the forum for a couple of weeks and just fetching up with the discussion. So please excuse, if this has already been addressed:
  
 The LKS uses pin 7 of the RJ45-I2S-Input to get a PCM or DSD indication. If you connect pin 7 to GND your signal will be interpreted as PCM. If connected to +3.3v your signal will be interpreted as DSD. The LKS reacts immediately to the pin-7-input and displays PCM or DSD on its front LCD even before the actual I2S-PCM or DSD signal is applied on the other pins. This way you can manually force DSD/PCM-interpretation. You can also connect pin 7 to a GPIO, if using your own micro-controller for I2S output.
  
 Best regards,
 Felix


----------



## fjc36

tribon said:


> 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.


 

 On post #150, Are you sure about the worth of add-on effect of extra transformer? Remind you, only if you test the effect step by step, as transfer the usb card and power supply then,  test the transformer later, so you can tell the improvement, one step a time tells more clear. A AB test is even better.  It even better to have the interface card change first, the the power supply, then the transformer. My 0.02 dollars.


----------



## justbenice

dadbeh said:


> I have ordered the new Burson V5i (x4) and the venerable LME49860 (x4) to roll. right now my LKA DA003 has 4 OPA1612 in the output. so ill be replacing all 4 and listening.


 
 Burson said the V5i should not use in the I/V section. So you should but the V5i on output stage only !


----------



## fjc36

b0bb said:


> The MUSES01 in the RCA section makes it a little bit warmer and that is about all.
> 
> LKS made a trade off in order to use the lower cost Crystek crystal and tried to adjust the I/V and filter section to compensate, changing the opamps undoes some of the compromises.
> 
> ...


 
 Dear bobb,
 What is the jitter error in CCHD 575? 82 fs right?  then what is the error for CCHD 950X in fs? less then 60fs ? Are both are in the 25 ppm deviation class? How about  the noise levels in them? It seems 957 even has a lower noise level, but aim for 50MHz use. I like to clear this then asking maker swap the 574 to 950X (the main XO) during place an order, I need to be persistant. Thanks for your effort. Seriously, viewing other well-known DACs layout picture, they do use computer grade capacitors more often than the normal audio grade on their main board.
  
 fjc36


----------



## fjc36

fjc36 said:


> Dear bobb,
> What is the jitter error in CCHD 575? 82 fs right?  then what is the error for CCHD 950X in fs? less then 60fs ? Are both are in the 25 ppm deviation class? How about  the noise levels in them? It seems 957 even has a lower noise level, but aim for 50MHz use. I like to clear this then asking maker swap the 574 to 950X (the main XO) during place an order, I need to be persistant. Thanks for your effort. Seriously, viewing other well-known DACs layout picture, they do use computer grade capacitors more often than the normal audio grade on their main board.
> 
> fjc36


 

 Odd, it seems in the spec, CCHD 950X has jitter error in 1ps, much higher than the CCHD 575 series. Noise level at 25mhz, 100mhz?


----------



## b0bb

fjc36 said:


> Dear bobb,
> What is the jitter error in CCHD 575? 82 fs right?  then what is the error for CCHD 950X in fs? less then 60fs ? Are both are in the 25 ppm deviation class? How about  the noise levels in them? It seems 957 even has a lower noise level, but aim for 50MHz use. I like to clear this then asking maker swap the 574 to 950X (the main XO) during place an order, I need to be persistant. Thanks for your effort. Seriously, viewing other well-known DACs layout picture, they do use computer grade capacitors more often than the normal audio grade on their main board.
> 
> fjc36


 
  
 The 575 has the lowest rms jitter of the lot at 82fs, the 950X is about 500fs.
 Jitter below 1ps and phase noise below -85dB @10Hz. is usually good enough for delta-sigma DAC audio, any more that is just a waste. 
  
 The 575 makes the LKS sound very harsh and bright which is one of the typical criticisms of the Sabre32, it was one of the first things I removed from the LKS.
  
 The 950X makes the presentation more organic and analog like. The 950X is the wide temp variant of the 950, it is a better cut of quartz with fewer stress points, to do better one would have to go to a stress compensated (SC) cut and the cost is usually > 100 USD.
  
 The drift with temp on the 950 is better (25ppm vs 50ppm on the 575).
  
 A better option is the Abracon AOCJY OCXO, it is about 1.5X the cost of the 950X and is one of the few low power consumption OCXOs that can be dropped into the LKS without overloading the voltage regulator. The Abracon is cheap because is it is not a SC crystal.
  
 The 575 was popular a few years ago but the newer designs have stopped using them.
  
 Use the computer grade caps only on the digital side and not on the analog or mixed/analog digital side, the Sabre32 has 3 separate power rails digital, mixed and analog.


----------



## fjc36

Thank you, I almost convinced by the manufacturer, they shear says 575 is better and more stable because its low jitter. Now I have to insist. Can you point out the pure digital part of the PSU to replace by computer grade cap., I am worry to bark the wrong tree on the mix region. Is there any  mixed region after the DAC chips?  What is the diode spec to replace all the original Philips BYW29 provided by the maker - LKS audio (point out the  page/ ref number is enough for me to look it. The  PC caps and the diodes have to be replaced by myself, I dare not to ask for a factory installation. DIY bring fans. Perhaps I should try that only after burning out. If possible I will try different channels for A/B compare, since it is a two channel D/A here. I always try every thing upgrade by A/B test and in a duration of two minutes max. listening, I do not have a photographic memory.  Cheers, and many thanks.


----------



## fjc36

Thank you, I was almost convinced by the manufacturer, they claim 575 is better and more stable because its low jitter. Soft may comes from the unstable (high jitter) of the XO. Now I have to insist. May be a adaptor to be placed before delivery and I should try to hear and feel it myself. Hearing is believing. 
Q1 What size and spec of the adaptor, an industrial common 14 pin IC socket?
  
Q2 Can you point out the locations of pure digital part on the board to replace by computer grade cap or OSCON., I am worry to bark the wrong tree on the mix region. Is there any  mixed region behind the DAC chips?  
  
Q3 What is the  diode serial number for replacing all the original Philips BYW29 high speed diodes which are installed by the maker of LKS audio. The  PC caps and the diodes have to be replaced by myself, I dare not to request for a factory service. I will try that only after burning out. If possible I will try different channels an A/B test, since it is a two channel D/A here. I always try every thing upgrade by A/B test and in a duration of two minutes max. listening, I do not have a photographic memory.  
  (point out the  related pages/ post numbers  is enough for me to look it is enough.
Cheers, and many thanks.

  
 fjc36


----------



## b0bb

Before you attempt to change anything on the DAC, use it for a at least a month to allow it to burn in, you might like it without any changes.

The details on the sockets and diodes are in this thread, modification is not recommended unless you already have used the DAC for a period of time.
Suggest you take the time to read thru the previous posts for the relevant info.


----------



## b0bb

With the recent discussion on the ultra low jitter Crystek CCHD-575, I wrote a tool to calculate the r.m.s jitter number from the commonly available phase noise plots.
  
 This provides the benefit of being to get the jitter numbers for the close-in case that I am interested in. This is the jitter in the 10Hz-10kHz range deviation from the XO carrier frequency.
  
 The result of this is a more balanced evaluation of the phase noise characteristics of the various XOs in common use in DACs compared to relying on the manufacturer provided  jitter numbers.
  
 The tool uses a piece wise curve integration algorithm.
 Maxim has an appnote the describes this in detail
 https://www.maximintegrated.com/en/app-notes/index.mvp/id/3359
  
 Raw output from the tool

  
 The last line of the output is the example XO used in the Maxim appnote.
 It is there to make sure the math is correct. The example XO has a 4.1ps rms jitter
  
 Here is the phase noise plot of the 100MHz CCHD-575.

  
 The r.m.s jitter spec from Crystek is 82fs (12kHz-80MHz)
 Calculated output from the tool based on the datapoints in the graph above;
  
         CCHD-575 DS fc= 100.00MHz BW=(10.00kHz-100.00MHz) RMS Jitter: 82.281fs
  
 This pretty close, the tool uses a 10kHz - 100MHz bandwidth so the net phase noise is higher.
  
 Recasting the data to the 10Hz to 10kHz range to make comparisons of the various XOs.
  
         AOCJY1 fc=  10.00MHz BW=(10.00Hz-10.00kHz) RMS Jitter: 1596.037fs
         CCHD-575 fc= 100.00MHz BW=(10.00Hz-10.00kHz) RMS Jitter: 151.769fs
         CCHD-950 fc= 100.00MHz BW=(10.00Hz-10.00kHz) RMS Jitter: 226.627fs
  
 The AOCJY1 is the OCXO I am currently using on the LKS, jitter is 1.6ps considerably worse that the 2 Crysteks.
 It is best sounding XO in my collection, I am comparing this to my Yggy.
  
 Equipped with the OCXO, the LKS will outperform the Yggy (bigger, more transparent soundstage, better bass slam and transient handling)
  
 Abracon unfortunately does not supply info for the 100MHz version in the public datasheets.
  
 Th difference between the 2 Crysteks are also much reduced when looking at the close-in situation.
 152fs for the CCHD-575 vs 227fs for the CCHD-950, both are extremely good, well within the femtoclock range.
  
 The main thing the OCXO has over the Crysteks is stability, 50ppb vs 50ppm on the stock LKS CCHD575, about 3 orders of magnitude more stable. I am beginning to think this is the more important parameter.
  
 This is a "bottom-of the barrel" unit, something nice like the Ultra low phase noise OCXOs from Wenzel Associates or similar might take this to the next level.
  
 On a separate topic, I was curious about the numbers of the 22MHz units specifically the NDK NZ2520SD vs the Crystek CCHD575.
  
      nz2520sd_22M fc=  22.58MHz BW=(10.00Hz-10.00kHz) RMS Jitter: 62.696fs
      cchd575_22M fc=  22.58MHz BW=(10.00Hz-10.00kHz) RMS Jitter: 221.180fs
  
 The NDK rms jitter number is superb.
 The 22MHz version of the CCHD-575 is actually slightly worse than the 100MHz version, 221fs vs 152fs


----------



## prot

That's avery useful calculator b0bb, many thx. 

Other than phase noise & stability, are there other clock-properties that may influence the sound?

And also what would be your choice of a highend ocxo for an ess dac? I did check some but the ocxo's either need to much power (>1w) or have too long warming times (>1min) or are too expensive. Usually all three are true.


----------



## fjc36

Dear B0bb,
 Thank you again for your advise. I have read this forum again, and take notes for the upgrade and their parts number, it is all there in details. I eventually like to have a XO socket installed for comparison before and after the baking in. Have you try switch back to XO 575 and compare with 950X after finalize the up-grades ? . If you did, please tell us your findings. So may goes to the OP to draw a conclusion.  I think, it is troublesome but will be fair for have a final, all small change add up may have effects including our hearing. 
 All for the best,
  
 fjc36


----------



## b0bb

fjc36 said:


> Dear B0bb,
> Thank you again for your advise. I have read this forum again, and take notes for the upgrade and their parts number, it is all there in details. I eventually like to have a XO socket installed for comparison before and after the baking in. Have you try switch back to XO 575 and compare with 950X after finalize the up-grades ? . If you did, please tell us your findings. So may goes to the OP to draw a conclusion.  I think, it is troublesome but will be fair for have a final, all small change add up may have effects including our hearing.
> All for the best,
> 
> fjc36


 

 I sometimes put the CCHD575 back in, it never stays in for long, makes the LKS sound like a common delta sigma DAC.
 Here is a picture of a few other XOs I tried.
  
 If you like the warm tubey sound the Epson XB42 will make the LKS sound like a vinyl record on a turntable.


----------



## b0bb

prot said:


> That's avery useful calculator @b0bb, many thx.
> 
> Other than phase noise & stability, are there other clock-properties that may influence the sound?
> 
> And also what would be your choice of a highend ocxo for an ess dac? I did check some but the ocxo's either need to much power (>1w) or have too long warming times (>1min) or are too expensive. Usually all three are true.


 
  
 The type of XO is also important, for example there are XOs that do not use quartz like the Epson XB series, these are surface acoustic wave oscillators, very warm sound.
 These is also the MEMS, micromachined silicon pendulums, they are very robust but no one seems to use it for audio, might get around to trying it.
  
 I do not have a specific recommendation beyond the Abracon AOCJY1, it turned out better than expected, as this was experimental I did not want to spend too much money on it.
  
 The next step is to use an OCXO with a SC cut crystal, these have much better jitter characteristics and they start from 250 USD.
 The power is not a real issue unless it is a drop-in replacement, fast warm up ( < 30s) OCXO just cost more money, 350 USD and up.
  
 The Pulsar Clock stuff is nice but they have gone quiet, their design appears similar to the one from Magic Crystal, a Russian company.


----------



## b0bb

The CCHD575 has a 50ppm stability, this means the carrier frequency changes by 50ppm for each 1 degC in temperature (more accurately it is per degree Kelvin).
  
 This translates to 500fs change in the timing period.
  
 The AOCJY1 OCXO is rated at 50ppb, this translates to 0.5fs.
  
  
 3 degC is about the difference in temp change when a window is opened or the AC  turned on, on a warm day.
  
 CCHD-575@50ppm will see up to a 1500fs change in the timing
 CCHD-950@25ppm will see  change of 750fs.
 AOCJY1@50ppb will change by 1.5fs
  
 If we look back at the r.m.s jitter calculated at a controlled temperature
 CCHD-575 is 151fs
 CCHD-950 is 227fs
 AOCJY1 is 1596fs
  
 The number in a real application is as follows
 CCHD-575   1651fs
 CCHD-950    977fs
 AOCJY1       1598fs
  
 I think this is partly why the OCXO holds its own despite an apparent worse rms jitter number.


----------



## abartels

b0bb said:


> The CCHD575 has a 50ppm stability, this means the carrier frequency changes by 50ppm for each 1 degC in temperature (more accurately it is per degree Kelvin).
> 
> This translates to 500fs change in the timing period.
> 
> ...


 
  
 Hi B0bb,
  
 Just curious, most OCXO's need 5V to operate, Crysteks need 3.3V. Does the Abacron need 3.3V too or did you feed it with 5V?
  
  
 Regards,
  
 Alex
  
 BTW, I tried replacing Xpresso's on Hifiberry DAC+Pro with NZ2520SD which delivers a LESS detailed soundstage, not is big and not as wide too....
 But, NZ2520SD have better bass control.......
  
 Regards,
  
 Alex


----------



## b0bb

abartels said:


> Hi B0bb,
> 
> Just curious, most OCXO's need 5V to operate, Crysteks need 3.3V. Does the Abacron need 3.3V too or did you feed it with 5V?
> 
> ...


 

 The Abracon is a 3.3V part.
  
 The NDK may not be able to drive the HiFiBerry sufficiently.
  
 The Xpresso has a 3.3ns rise time, for 3.3V logic into a 15pF load, this gives about 15mA.
 The NDK datasheet quotes a 6ns risetime, this puts the NDK current capability at 7.5mA


----------



## fjc36

Dear Bobb,
 If not going to the expensive OC type, you do recomend the Abracon Ablno fix freq 100mhz, better than the Crystek -950X and much better than the 575 right?

  
 I think you do mean the regular XO, not the variable VCXO, the cost  of  standard XO is very reasonable around US $ 10-15 only. Abracon VCXO  will cost around $ 30-40.
 Types of XO to chose

 
 OCXO Oscillators (517)
  






TCVCXO Oscillators (980)
  





VCSO Oscillators (73)
  





Programmable Oscillators (25,821)
  





TCXO Oscillators (2,681)
  





VCXO Oscillators (1,703)
  





Standard Clock Oscillators (37,555)
  





VCO Oscillators (594)


----------



## b0bb

fjc36 said:


> Dear Bobb,
> If not going to the expensive OC type, you do recomend the Abracon Ablno fix freq 100mhz, better than the Crystek -950X and much better than the 575 right?
> 
> 
> ...


 
  
 I recommend the 950X as the first choice. The ABLNO is a mixed bag, it is quite an aggressive, bright and forward sounding presentation.
 Get both if you want to experiment but use the 950X if have to chose one.
  
 The ABLNO is the fixed frequency, ABLNO-T and ABLNO-T2 are VCXOs.


----------



## fjc36

b0bb said:


> I recommend the 950X as the first choice. The ABLNO is a mixed bag, it is quite an aggressive, bright and forward sounding presentation.
> Get both if you want to experiment but use the 950X if have to chose one.
> 
> The ABLNO is the fixed frequency, ABLNO-T and ABLNO-T2 are VCXOs.


 
 Thanks, In our case, we should select the fixed type XO right?  (since there is no intension of utilize voltage control at pin 1 in this DAC circuit design), though VCXO provides a way through feed back to stablize the OSC freq shift or swing.

  I will try purchase a 950X, and wait till your latest discovery
 . 
 fjc36


----------



## b0bb

fjc36 said:


> Thanks, In our case, we should select the fixed type XO right?  (since there is no intension of utilize voltage control at pin 1 in this DAC circuit design), though VCXO provides a way through feed back to stablize the OSC freq shift or swing.
> 
> I will try purchase a 950X, and wait till your latest discovery
> .
> fjc36


 
  
 950X is a fixed type XO, avoid VCXO unless you want to experiment.


----------



## prot

http://www.ndk.com/en/ad/2013/001/pdf/c_NH47M47LA_e.pdf
Pretty amazing phase noise numbers but the 5ppm stability is nothing special (or I did misread something). 
Anyone who tried that new wonderclock already?


----------



## fjc36

Dear B0bb,
 What is your idea about the development of MQA? A new codec system developed by Meridian Audio claim to be solution for the high-res music? What will happen to the conventional DAC such as the LKS MH-DA003? Redesign the DAC IC chip to include the MQA codec?
 thanks,
  
 fjc36


----------



## b0bb

fjc36 said:


> Dear B0bb,
> What is your idea about the development of MQA? A new codec system developed by Meridian Audio claim to be solution for the high-res music? What will happen to the conventional DAC such as the LKS MH-DA003? Redesign the DAC IC chip to include the MQA codec?
> thanks,
> 
> fjc36


 

 To get the best out of MQA a redesign is required. Playback on non MQA specific hardware appears possible provided you are willing to accept 15.8bit playback resolution on a 24bit track.
  
 MQA has a lot to prove, especially in areas like being DRM free, MQA insists it does not contain DRM, MLP its older sibling, partially failed because of this.
 The other big one is watermarking. This is an intentional corruption of the audio signal to embed tracking data, MQA says no watermarking, I will wait and see, this killed DVD-A as a viable commercial product.
  
 Lastly, I do not know if the decoder will be free to use in things like foobar.
  
 Paul McGowan from PS Audio posted a short impression of MQA
 http://www.psaudio.com/pauls-posts/mqa-thoughts/
  
 More info from MQA's inventor, Bob Stuart
 http://www.computeraudiophile.com/content/694-comprehensive-q-mqa-s-bob-stuart/
  
  
 More info about watermarking on audio.
 http://www.mattmontag.com/music/universals-audible-watermark


----------



## fjc36

To B0bb,
 If a redign of the DAC happens, how long do you think it will happen? Is that mean the current purchased LKS has to be retired on the high res digital stream object? Shall we delay the buying and observe?
  
 fjc36


----------



## fjc36

I am trying to following the threads of MQA, it seems logical to transform digital data by log scale( like we do on the volume control)  to avoid waste. A linear scale on sampling and on precision may not be necessary. But in a long run we may find another type of error happens in MQA just like we found jitter, digital filter fault, and fidelity on CD format etc.
  
 fjc36


----------



## b0bb

fjc36 said:


> To B0bb,
> If a redign of the DAC happens, how long do you think it will happen? Is that mean the current purchased LKS has to be retired on the high res digital stream object? Shall we delay the buying and observe?
> 
> fjc36


 
  
 That is an open question, if you are looking to buy a DAC now, get a conventional DAC like the LKS and check back in a few years to see if there is sufficient market interest in MQA  ( things like DACS supporting MQA and MQA music )


----------



## 3rdmortal

Sorry, i didn`t understand clearly. So if i want to change a clock is it an easy fix or you need to use soldering tool for that? Thank you in advance.


----------



## b0bb

3rdmortal said:


> Sorry, i didn`t understand clearly. So if i want to change a clock is it an easy fix or you need to use soldering tool for that? Thank you in advance.


 
  
 Soldering tool required to remove the existing clock and to install the replacement clock.


----------



## fjc36

b0bb said:


> That is an open question, if you are looking to buy a DAC now, get a conventional DAC like the LKS and check back in a few years to see if there is sufficient market interest in MQA  ( things like DACS supporting MQA and MQA music )


 
 Yes, I did my  study for buying a new  Hi-RES DAC to catch up the digital  stream trend. As a DIY hobbist and a classical music fan, I do tell the sonic difference between CD and SACD (serious recording). So, the MQA will not be popular over nights, months. Few years is fine for most of us, I guess.


----------



## b0bb

Updated my XO jitter calculator to include data from the Pulsar OCXO and the Accusilicon AS318B.
 The Accusilicon is used in the Gustard X20U.
  
 The Pulsar OCXO jitter is 10x less than the conventional XOs.
 Nice to see Accusilicon in something in the X20U's price category, it is unfortunate Gustard used this on the USB bit clock and not the DAC master clock XO.
       AOCJY1            fc=  10.00MHz    BW=(10.00Hz-10.00kHz)      RMS Jitter: 1596.037fs
      CCHD-575         fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter: 151.769fs
      CCHD-950         fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter: 226.627fs
      AS318-B            fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter: 200.494fs
      Pulsar Max        fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter: 35.115fs
      Pulsar Typ         fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter: 20.174fs
      nz2520sd_22M  fc=  22.58MHz    BW=(10.00Hz-10.00kHz)      RMS Jitter: 62.696fs
      cchd575_22M    fc=  22.58MHz    BW=(10.00Hz-10.00kHz)      RMS Jitter: 221.180fs
      CCHD-575 DS    fc= 100.00MHz   BW=(10.00kHz-100.00MHz) RMS Jitter: 82.281fs
      Maxim Ex.          fc= 155.52MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter: 4074.163fs


----------



## fjc36

Just read about the new generation ESS 3038 pro, and the obslete of 3018. Curous about its development on the market. Just before I like to step in the cleared water, it is getting muddy. May someone try distinguish the difference btw 9018 and 9028, since it seems interchangeable, an upgrade?


----------



## fjc36

It seems the difference btw ESS9038pro and 9028pro is on the programablity. The block diagrams are the same. General application and benifits are the same. I notice that one difference stays on the application of digital filters. 9028pro has eight pre-set filters, 9038pro allows customer built others, may be its very important. Other deviations besides THD and noise level?
  
 Can ESS chip raise the sampling freq. on the input digital data to make analog more close to the original like the CHORD DAVE trying to acheive?


----------



## prot

The 9028 is a drop-in replacement for 9018 and 9038 is not. That would indicate that the chips and/or firmware are quite different. 
And IIRC, the THD and DNR measurments for 9038 are 5-10db better. 

And btw this seems to be the first Dac with a 9038 chip http://www.digitalaudioreview.net/2016/05/ayre-acoustics-show-off-qx-5-twenty-digital-hub/

b0bb
That ayre uses some interesting clocks from Morion http://www.morion.com.ru/eng/oscillators/ocxo
Some of them look quite fit for an Ess Dac, maybe you can add them to your database


----------



## fjc36

Sorry, corrections, it is ES 9028pro and 9038pro, not any 2028 or 3038.
 May be same block diagram and function do not represent exact layout.  Interesting.
 Some one saying that, 9028pro good at two-channel , and 9038pro good at multi-channel, really?


----------



## b0bb

MV269 is the only OCXO in Morion's range that will work in the LKS as a straight drop-in, r.m.s jitter is about 451fs.
 http://www.morion.com.ru/catalog_pdf/33_MV269.pdf
 Morion is not widely available. Ayre likely has theirs custom made.
  
 Abracon        AOCJY1              fc=  10.00MHz    BW=(10.00Hz-10.00kHz)      RMS Jitter: 1596.037fs
 Crystek         CCHD-575           fc= 100.00MHz  BW=(10.00Hz-10.00kHz)       RMS Jitter: 151.769fs
 Crystek         CCHD-950           fc= 100.00MHz  BW=(10.00Hz-10.00kHz)       RMS Jitter: 226.627fs
 Accusilicon   AS318-B              fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter:  200.494fs
 Pulsar           Pulsar Max          fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter:    35.115fs
 Pulsar           Pulsar Typ           fc= 100.00MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter:    20.174fs
*Morion         MV269                 fc= 100.00MHz  BW=(10.00Hz-10.00kHz)      RMS Jitter: 450.651fs*
 NDK             nz2520sd_22M    fc=  22.58MHz    BW=(10.00Hz-10.00kHz)      RMS Jitter:    62.696fs
 Crystek        cchd575_22M       fc=  22.58MHz   BW=(10.00Hz-10.00kHz)      RMS Jitter:   221.180fs
 Crystek        CCHD-575 DS      fc= 100.00MHz  BW=(10.00kHz-100.00MHz) RMS Jitter:     82.281fs
 Maxim          Example               fc= 155.52MHz  BW=(10.00Hz-10.00kHz)      RMS Jitter: 4074.163fs


----------



## abartels

b0bb said:


> MV269 is the only OCXO in Morion's range that will work in the LKS as a straight drop-in, r.m.s jitter is about 451ps.
> http://www.morion.com.ru/catalog_pdf/33_MV269.pdf
> Morion is not widely available. Ayre likely has theirs custom made.
> 
> ...


 
  
 Yes I suppose you're right, MV269 is far from ideal..... The Pulsar's are really good, but very expensive 
 NDK-SD seems to be the very good choice, but not in every circuit, as you told me before 
 Btw, I've got samples from XpressO Ultra (FXU-HC73x series) from FOX Electronics, will try to replace the
 standard FXO-HC73x's on DAC+Pro. Should be rather audible, they have about 1/3 of jitter


----------



## prot

Thx for the update b0bb. 
I was actually looking at http://www.morion.com.ru/catalog_pdf/39_MV317.pdf
Better phasenoise numbers, excellent stability, relatively low power, etc ... unfortunatelly only comes with 5/12V inputs so not an easy drop-in replacement for LKS. 
Might be worth the effort though .. the Morions seem to be quite reasonably priced. 
Couldnt find a price for that model but here's a similar one selling for peanuts https://www.ebay.de/itm/262495153142

abartels
Does the new ndk duculon fit the reqs for your dac+ board ?
http://www.ndk.com/en/ad/2013/001/pdf/c_NH47M47LA_e.pdf. At least according to their marketing it is "the best for audio". The phase noise looks excellent and they should be affordable.


----------



## b0bb

prot said:


> Thx for the update @b0bb.
> I was actually looking at http://www.morion.com.ru/catalog_pdf/39_MV317.pdf


 
 It has the wrong type of output, sinewave.


----------



## abartels

prot said:


> Thx for the update @b0bb.
> I was actually looking at http://www.morion.com.ru/catalog_pdf/39_MV317.pdf
> Better phasenoise numbers, excellent stability, relatively low power, etc ... unfortunatelly only comes with 5/12V inputs so not an easy drop-in replacement for LKS.
> Might be worth the effort though .. the Morions seem to be quite reasonably priced.
> ...


 
  
 The DuCULoN is available at 45.1584 MHz and 49.152MHz only. DAC+Pro would work with the HCMOS version, but AK4495 needs 22.5792MHz and 24.576MHz.
 But, more interesting is it's pricelevel, they go for about $1550 which is not what I call affordable, maybe you've got a stash of dollars somewhere?
 Feel free to surprise me, hahahahaha


----------



## justbenice

I'v tried a few opamps in my LKS MH-DA003 :
  
 +HDAM china made opamps from Ebay  : 34usd/ a pair
 +Supreme Sound Opamp V5i : 70USD/a pair
 +Muses01 : 92,5USD/a pair 
  


  
  
 + The HDAM china opamps : The mid and bass was ok, but the treble was worst, very high and thin treble. 
 + Burson  V5i :  Very good opamps, it have very detail and clear treble, good and thick mid, deep and very clear bass. It have very good balance in Treble-Mid-Bass. 
 + Muses01 : Like it name, muses, it have sweet mid, sweet bass, but the treble was less clear and detail as V5i.
  
 Overall, i like the V5i more because it have clear and detail treble an very balance in Treble - Mid - Bass so the sound stage wider, make me feel  enjoy to listen music.
 The muses01 is good if you like some slow, soft music like Jazz.


----------



## abartels

justbenice said:


> I'v tried a few opamps in my LKS MH-DA003 :
> 
> +HDAM china made opamps from Ebay  : 34usd/ a pair
> +Supreme Sound Opamp V5i : 70USD/a pair
> ...


 
  
 Did they all get 150 hours to settle in? 150 hours PLAYING music?


----------



## justbenice

Yes. It take me a month to burn in.


----------



## b0bb

justbenice said:


> Yes. It take me a month to burn in.


 

 How does the V5i compare to the V5SS (the red ones) you were using earlier?


----------



## justbenice

b0bb said:


> How does the V5i compare to the V5SS (the red ones) you were using earlier?


 
 The V5 (red one) have problem, it dead after 2 day burnin, so they said it was not compatible with LKS DAC and send me a V5i. That why i don't have a chance to compare the V5, V5i, Muses01.


----------



## fjc36

b0bb said:


> Updated my XO jitter calculator to include data from the Pulsar OCXO and the Accusilicon AS318B.
> The Accusilicon is used in the Gustard X20U.
> 
> The Pulsar OCXO jitter is 10x less than the conventional XOs.
> ...


 
 I have read from the article, mytek mahatten ($5000) use AOCJY1 as the main XO, and next generation mytek Mahatten II will use CCHD950. Cheers to b0bb. It must be a correct decision to replace CCHD950 of lower jitter CCHD-575 for the sonic refining of LKS ES9018D mh-003.


----------



## dacusb

Dear B0bb,
  
 My LKS 003 has just arrived and I just wish to upgrade it by replacing the existing XO with the Epson XB42. Unfortunately I could not find any offer even though I have searched everywhere using google. Can you help?
 Thank you very much.


----------



## b0bb

dacusb said:


> Dear B0bb,
> 
> My LKS 003 has just arrived and I just wish to upgrade it by replacing the existing XO with the Epson XB42. Unfortunately I could not find any offer even though I have searched everywhere using google. Can you help?
> Thank you very much.


 

 Epson does not appear to make that part anymore.
  
 The closest is https://support.epson.biz/td/api/doc_check.php?dl=brief_XG-1000CA_en.pdf (XB4Y).
 Pin1 and Pin 4 have to be connected via a 1k  ohm resistor for this to work.
  
 I have not used it.


----------



## abartels

Hi B0bb,
  
 Maybe you're interested in trying this one:
  





  
 It's from TaoBao, you can order it thru Agents. I use Bhiner.com which is very good in my opinion. Those are RMB120 which is about $18 , yes, they are a real bargain!
  
 Probably you have to copy and paste this link into your browser for getting it to work:
 https://world.taobao.com/item/15260673023.htm?spm=a312a.7728556.1414651174895.3.O1fZix&scm=1007.10146.6070.0&id=15260673023&pvid=ac435acf-1353-4542-8fcb-ef811672d20c
  
 Operating voltage: 5V-30V
 Maximum output current: 200MA
 Input impedance: 1M
 Frequency Response: 0-200KHZ
  
 It's FET based input and Class-A
  
 I use it in my "MonsterDAC" where it performs miracles 
	

	
	
		
		

		
		
	


	



  
 I upgraded from LME49720HA (Milspec metal can) and in comparison to the OPA01 the LME sounds like an old portable transistor radio............
  
 I had to build an extension cable (from CAT7) and put 1000uF Nichicon Muse and a 0.01uF MKP close to the OPA01's psu. This works like a charm.
 Standard extension cable which they provide is very bad, I couldn't use that cable.
  
 Regards,
 Alex


----------



## b0bb

abartels said:


> Hi B0bb,
> 
> Maybe you're interested in trying this one:
> 
> ...


 
 I have seen these on Ebay for about 60 USD shipped.
  
 How much did Bhiner charge you for the service + shipping?


----------



## abartels

b0bb said:


> abartels said:
> 
> 
> > Hi B0bb,
> ...


 
  
 I didn't buy these with Bhiner, but Bhiner charges 10% fee and a standard fee of about $3. Shipment of 8x ETI-alike RCA plugs did cost me about €20 to The Netherlands
  
 I suppose it's about $40 including shipment, and probably $65 for two pieces.


----------



## kazcou

You find them on aliexpress for 33$ piece : op01


----------



## abartels

kazcou said:


> You find them on aliexpress for 33$ piece : op01


 
  
 That's a nice find!
  
 English site:
  
 http://www.aliexpress.com/item/OP01-top-dual-op-amp-module-better-than-the-OPA2604-LME49720HA-OPA2111/32693046536.html?spm=2114.30010308.3.9.xDwhof&ws_ab_test=searchweb201556_0,searchweb201602_3_10057_10056_10055_10037_10049_10033_10059_10058_10032_10017_405_404_10060_10061_10062_412,searchweb201603_6&btsid=b28e90e6-e4dc-4bc7-bd8b-73dbb5203383
  
 and this is the sellers store, he has many attractive components 
	

	
	
		
		

		
		
	


	



  
 http://www.aliexpress.com/store/1894205?spm=2114.10010108.0.38.JMH9ve
  
 You may have to copy / paste the link into your browser


----------



## b0bb

Updated my tool to add more info for a wider range of low phase noise XOs and OCXOs.
 The 100MHz XOs are 3.3V HCMOS output.
  

  
 Added the Abracon ABLNO XO about the same performance as the Accusilicon.
  
 The IHR units are OCXOs with Integrated Heating Resonators (IHR), the quartz crystal is directly heated.
 In order to keep the consumption power down, the IHR is sealed inside a vacuum chamber.
 This reduces the OCXO power consumption by a order of magnitude.
  
 I also added other interesting XOs
  
 The MSB Galaxy is a 6k+ USD clock from MSB, the Pulsar and MXODR from MagicXtal gets pretty close, when the jitter numbers are re-normalized for the operating frequency differences (100MHz vs 24.576MHz).
  
 MXODR is a double oven OCXO using IHR and a hybrid vacuum chamber.
  
 The Symmetricom SA.45s is low power chip-scale atomic clock (CSAC), phase noise in the close-in case for audio DAC use is pretty average.
 The SA.45s module starts at 1.2k USD.
  
  
 IHR OCXOs are the current state of the art in low power OCXOs making them ideal replacements of the existing XO in a DAC like the LKS.
  
 Internal construction of the IHR  Crystal module.

  
 Construction of the IHR XO

  
 References:
 http://www.magicxtal.com/customer/detail.php?ID=165


----------



## b0bb

Add new entry for the NDK Duculon 49.xxx MHz OCXO.
 The NDK(20.044fs) is comparable to the Pulsar (20.174fs) for RMS Jitter.
 MSB Galaxy is king-of-the-hill on this list.
  
 The table format is hopefully easier to read.
  
 LKS Compatible XOs:

ManufNameTypeFc(MHz)BW(Hz)RMS Jitter (fs)AbraconABLNOXO100.0010.00-10.00k200.923CrystekCCHD-575XO100.0010.00-10.00k151.769CrystekCCHD-950XO100.0010.00-10.00k226.627AccusiliconAS318-BXO100.0010.00-10.00k200.494VectronOX-405IHR100.0010.00-10.00k89.534VectronEX-401OCXO100.0010.00-10.00k89.658Micro CrystalSCOCXOHOCXO100.0010.00-10.00k159.949Dynamic Engineers IncOCXO3308CIHR100.0010.00-10.00k69.452CTSVFOV504IHR100.0010.00-10.00k89.620MTI-Milliren221OCXO100.0010.00-10.00k28.356PulsarPulsar MaxIHR100.0010.00-10.00k35.115*Pulsar**Pulsar Typ*IHR100.0010.00-10.00k*20.174*MorionMV269OCXO100.0010.00-10.00k450.651Magic XtalMXO37H/14IHR100.0010.00-10.00k58.573Magic XtalMXODR2xIHR100.0010.00-10.00k25.974
   
 Misc XOs:

ManufNameTypeFc (MHz)BW (Hz)RMS Jitter (fs)Abracon*AOCJY1OCXO10.0010.00-10.00k1596.037SymmetricomSA45s CSACCSAC10.0010.00-10.00k1428.198NDKNZ2520SDXO22.5810.00-10.00k62.696*NDK**Duculon*OCXO49.1510.00-10.00k*20.044*CrystekCCHD-575XO22.5810.00-10.00k221.180CrystekCCHD-957XO22.5810.00-10.00k310.181MSBGalaxyOCXO24.5810.00-10.00k16.176
  
 Notes:
 * The Abracon AOCJY1 is compatible for use in the LKS, it is listed in the Misc XO section as Abracon only provided the phase noise plots for the 10MHz XO on their datasheet.
  
  
 Experimental Controls:

ManufNameTypeFc (MHz)BW(Hz)RMS Jitter (fs)Crystek CCHD575XO10010.00k-100.00M82.281MaximExampleXO155.5210.00-10.00k4074.163


----------



## kotms

Hello Everybody. I'm new here, and this is my first post.
  
 I'm helping my friend to improve his LKS 003. He bought a Tiger ZX1215 convertor, and we want to install it in place of the stock  convertor. But, it is not a plug in, and we have no idea how to wire it in. There are many more holes on the new board than connectors on the old, and I'm not knowledgeable enough to figure out which should be implemented. So I'm looking for a diagram, and/or explanation on how to wire it in the existing spot.
  
 Any help deeply appreciated.
  
 Mark


----------



## b0bb

kotms said:


> Hello Everybody. I'm new here, and this is my first post.
> 
> I'm helping my friend to improve his LKS 003. He bought a Tiger ZX1215 convertor, and we want to install it in place of the stock  convertor. But, it is not a plug in, and we have no idea how to wire it in. There are many more holes on the new board than connectors on the old, and I'm not knowledgeable enough to figure out which should be implemented. So I'm looking for a diagram, and/or explanation on how to wire it in the existing spot.
> 
> ...


 

 The LKS uses the Amanero Combo384 USB to I2S board
 The datasheet contains the pinout of the module: http://www.amanero.com/drivers/combo384-D.pdf
  
 The Tiger board is a derivative of the Amanero according to its website, suggest contacting the manufacturer for further assistance.


----------



## kotms

Thank you


----------



## abartels

Hi B0bb,
  
 I have some XpressO Ultra XO's - FXU-HC73x series which you maybe could add to the list?
 Those are not the best specs, but maybe nice to have them in the list.
  
 http://www.foxonline.com/pdfs/FXU-HC73.pdf
  
 I have:
  
 FXU-HC738 (20ppm) 22.5792mHz
 FXU-HC736 (25ppm) 24.576 mHz
  
 Mounted them on Ian Canada's XO boards:
  

  
 Used some 3M AB5100S EMI/RFI absorbing material:
  

  
 Finally put Vishay 1837 0.01uF MKP's on top of them:
  

  
  
 They are burnin-in in Ian's FIFO II - Isolator - DUALXO II reclocker, and, so far so good 
  
 Use them, for testing, with a low-cost Chinese AK4495SEQ I2S-Only dac, together with Bursun V5i-D opamp (for reviewing)
  

  
  

  
 RPI2 using piCorePlayer 2.06, I2S output from GPIO thru Ian Canada's I2S output adapter fed into FIFO II.
  
 Sound so far: Astonishing!
 This set almost sounds like my "MonsterDAC" which, normally is a HUGE difference with this low-cost chinese dac, when fed I2S thru RPI+HB DAC+Pro
  
 Btw, SS V5i-D does a very good job too  Will review them when burned-in, next weekend.
  
 Finally Ian's FIFO II + Isolator + DualXO II board will be built-in in MonsterDAC. Can't wait, that's for sure 
  
  
 Regards,
 Alex


----------



## b0bb

abartels said:


> Hi B0bb,
> 
> I have some XpressO Ultra XO's - FXU-HC73x series which you maybe could add to the list?
> Those are not the best specs, but maybe nice to have them in the list.
> ...


 
 Here are the numbers.
  
  
 The r.m.s. phase jitter is the area under the phase noise plot averaged over the frequency span.
 The FXU-HC73 number is for 156.25MHz as described in the datasheet.
  

ManufNameTypeFc (MHz)Bandwidth (Hz)Jitter (fs)FOXFXU-HC73xXO156.2510-10k1605.452FOX*FXU-HC73x/ControlXO156.2510k-40M268.212
  
 *The calculated control numbers have an integration bandwidth of 10kHz-40MHz, this gives a marginally higher r.m.s jitter of 268ps vs the datasheet 260ps which used a bandwidth of 12kHz-20MHz


----------



## abartels

Hi B0bb,
  
 Thanks for adding them!
  
  
 Regards,
 Alex


----------



## penguin69

Hi
  
 First post on here, so go easy on me! 
  
 I've just acquired an LKS Audion MH-DA003, which has had certain modifications performed on it (the details of which I don't have yet).
  
 On listening to this DAC for the first time, I was a little disappointed in how it sounded compared to the modified Eastern Electric Minimax Supreme which I have owned and enjoyed for the last two years.
  
 With the EE Supreme, I had replaced the original opamps (NE5532 and NE5534 IC's) with single and dual discrete op amps from Dexa. The following link shows very similar (or possibly the same) dual op amps:
 http://www.newclassd.com/index.php?page=122&hv=1
  
 My MH-DA003 arrived with two pairs of Texas Instraments IC op amps installed. The print is very small, but a magnifying glass shows TI 1612A, so I suppose they are similar to those in the link below:
 http://www.ti.com/product/opa1612Hi
  
 Today I replaced the pair of 1612s located nearest to the unbalanced outputs with the Dexa's that I used in the Supreme. The sound is now less gritty and less thin compared to how it was with those TI IC op amps inline.
  
 As a result of this exercise, I have come up with some questions:
  
 1) I'm not very good at all at matching op amp specs to real world performance. The link I posted to the Dexa Op Amp describes supply current as: "typ. 14mA". Does this mean that this op amp drops out of Class A operation after 14mA?
  
 2) After replacing the first pair of TI 1612 IC op amps, I decided as a test to remove - and not replace - the remaining pair of 1612's (those located nearest to the 9018 chips). The DAC still operated ok through the unbalanced outputs. So, what is the function of the op amps I removed? Do they simply service the balanced outputs?
  
 3) The Dexas sound good to me. I also have a pair of Burson discrete dual Op Amps, which I will try later. I know it is a subjective thing, but from a technical perspective would any of you recommend against using the Dexas with the MH-DA003 based on their spec?
  
 4) I don't understand why my EE Minimax Supreme uses a pair of single op amps and a pair of dual op amps, whilst the MH-DA003 I acquired has two pairs of dual op amps. Is there a simple explanation about when to use single and when to use dual?
  
 Sorry if my questions are a bit ignorant, I'm not an Electronics Engineer, I'm more a hifi buff with an interest in and rudimentary understanding of electronics.
  
 Thanks!


----------



## b0bb

penguin140369 said:


> 1) I'm not very good at all at matching op amp specs to real world performance. The link I posted to the Dexa Op Amp describes supply current as: "typ. 14mA". Does this mean that this op amp drops out of Class A operation after 14mA?
> 
> 2) After replacing the first pair of TI 1612 IC op amps, I decided as a test to remove - and not replace - the remaining pair of 1612's (those located nearest to the 9018 chips). The DAC still operated ok through the unbalanced outputs. So, what is the function of the op amps I removed? Do they simply service the balanced outputs?
> 
> ...


 
 Comments to your questions
 1) I normally estimate the output stage bias current at 80% of the supply current. This gives a bias current of about 5.5 mA, the opamp falls out of ClassA at 2X this value or about 11mA of load current.
 (The DEXA you mentioned is a dual opamp so the supply current is 7mA for each half).
 To put things is perspective, the ES9018 has 8 DACs each producing 4mA current output at full scale.
 On the Dual Mono (8 DACs/ch) LKS, this is 32mA, on the EE (4 DACs/ch) this is 16mA.
 The DEXA does not appear to run in ClassA in any of the situations, the special edition that runs at 20mA supply current will work as the I/V converter on the EE but not the LKS.
  
 2)You removed the Current to Voltage (I/V) converter, the DAC is still connected via the I/V resistor so it continues to work in Voltage output mode instead of current output mode.
  
 3)The DEXAs will do ok in the unbalanced stage, less so for the I/V role for the reasons explained in (1)
  
 4)The EE uses a single pair of opamps, a pair of dual opamps, a pair of triodes and a bunch of capacitors that appear to be in the signal path. The LKS is a conventional DC coupled active filter with no caps directly in the signal path, can't say more without seeing the schematic of the EE


----------



## penguin69

Brilliant, thanks b0bb. Appreciate the response.
  
 The DAC actually sounds better in voltage output mode with only the discrete Dexa opamps in place than it does in current mode with the two TI 1612s in place.
  
 I will put one pair of TI chips back in for the I/V coversion, as the datasheet shows 55mA as the typical output current which, with my limited knowledge, would appear to be up to the job. Later this week I will look back through the thread and find something better to use - I think I saw Sonic Imagery Ticha 994's recommended for their high idling current.
  
 This should all be a good experiment. I thought the LKS would beat the EE Supreme hands down out of the box due to it employing twin ESS9018's vs the Supreme's single chip ... but this was obviously a simplistic notion as it doesn't get close, even with the mods built in to the LKS (which I am not familiar with yet but will learn about and then compare to the recommendations here).


----------



## b0bb

penguin140369 said:


> Brilliant, thanks b0bb. Appreciate the response.
> 
> The DAC actually sounds better in voltage output mode with only the discrete Dexa opamps in place than it does in current mode with the two TI 1612s in place.
> 
> ...


 

 The I/V converter is also the first stage of the analog filter, it gets rid of the Delta-Sigma conversion artifacts above 1MHz.
  
 Over the long term this can do a lot of damage to specific types of speakers especially things like beryllium tweeters if the first stage is removed.


----------



## penguin69

Thanks again b0bb. I think the tweeters in my Kudos speakers are about $500 a piece for replacements so that is very valuable information.
  
 I restored the 1612's late yesterday and it compromised the SQ. I was told by the seller of DAC that these op amps were good quality and up to the job, however my ears are telling me otherwise. With the 1612's in place, the sound has that slightly brittle digital signature, making the music unrelaxing, and - oddly - there is something missing in the mid-range: vocals sound thin and unnatural. My hearing isn't great so I am surprised that I am picking these things up.
  
 I looked at one of the pics earlier in this thread and it seems, b0bb, that you have settled for Bursons on the unbalanced stage, with (what look like) the Sonic Imagery discrete op amps for the I/V conversion. I will put in an order for a pair of the latter. (I also have some discrete dual Burson op amps at home but they are older, although they look somewhat like the v4's.)
  
 Tomorrow I will look again at the board to figure out the path for the balanced signal, which I would like to test out also.
  
 I am still a little bit flummoxed as to why my single chip MiniMax DAC is outperforming the MH-DA003 DAC with its two chip architecture and seemingly clean design. Let's hope persistence and further tweaking pays off...


----------



## rayofsi

Out of curiosity, has anyone compared this to something like the gustard x20u?
 I have a x20u, but am considering this unit.
  
 what are some dacs that this has been compared against?


----------



## b0bb

penguin140369 said:


> Thanks again b0bb. I think the tweeters in my Kudos speakers are about $500 a piece for replacements so that is very valuable information.
> 
> I restored the 1612's late yesterday and it compromised the SQ. I was told by the seller of DAC that these op amps were good quality and up to the job, however my ears are telling me otherwise. With the 1612's in place, the sound has that slightly brittle digital signature, making the music unrelaxing, and - oddly - there is something missing in the mid-range: vocals sound thin and unnatural. My hearing isn't great so I am surprised that I am picking these things up.
> 
> ...


 
  
 The brittle sound quality comes from the CCHD-575 XO used in the LKS, putting a better quality opamp will bring this to the foreground.
  
 Opamp replacement is easy but does not return much on that investment until the XO is replaced with something better like the CCHD-950X, this is something to keep in mind before putting down the cash for a  Ticha 994.


----------



## penguin69

b0bb said:


> The brittle sound quality comes from the CCHD-575 XO used in the LKS, putting a better quality opamp will bring this to the foreground.
> 
> Opamp replacement is easy but does not return much on that investment until the XO is replaced with something better like the CCHD-950X, this is something to keep in mind before putting down the cash for a  Ticha 994.


 

 Thanks as usual b0bb. The LKS I have acquired already has an upgraded oscillator amongst its mods - I'll check which one it is and report back, I expect it is on the list that exists in this thread.


----------



## penguin69

penguin140369 said:


> Thanks as usual b0bb. The LKS I have acquired already has an upgraded oscillator amongst its mods - I'll check which one it is and report back, I expect it is on the list that exists in this thread.


 

 Back again.
  
 So, the oscillator mod appears to be as follows: the stock XO (CCHD575) has been lifted out from the PCB and moved to a small separate board providing dedicated power regulation.
  
 So good call on the stock sound b0bb, you spotted the XO sound just from my description.
  
 Looking through this thread, it looks like the Pulsar XO is the preferred replacement. I will see how I can source it.
  
 Access to the XO and the small pins means I cannot perform this mod with my current, rather basic soldering iron. Any recommendations for an iron I can use for work with these kind of smaller components?
  
 Also, and on a separate note, does anyone have the pinout for the ESS9018? It seems to be a closely guarded secret. I've looked before and not had much luck. it would help me understand better what is going on.


----------



## penguin69

Ok, is the low jitter pulsar clock in the XO table on page 20 of this thread referencing this OCXO below:
  
http://www.pulsarclock.com/Clock.html
  
 Or is it referencing another one?
  
 (Sorry for all the questions)


----------



## b0bb

penguin140369 said:


> Back again.
> 
> So, the oscillator mod appears to be as follows: the stock XO (CCHD575) has been lifted out from the PCB and moved to a small separate board providing dedicated power regulation.
> 
> ...


 
  
 Post pictures of your LKS and I can take a closer look.
  
 If the XO has been put on a separate board thinks are easier, just drop in  a 14pin dip socket and solder it in.
  
 Here is mine.

  
  
 The ES9018 datasheet is around, google for it with the keyword "ES9018 datasheet"


----------



## b0bb

penguin140369 said:


> Ok, is the low jitter pulsar clock in the XO table on page 20 of this thread referencing this OCXO below:
> 
> http://www.pulsarclock.com/Clock.html
> 
> ...


 

 Pulsar is the clock I am currently using


----------



## penguin69

Thanks b0bb.
  
 I already have the 9018 datasheet:
  
http://pdf1.alldatasheet.com/datasheet-pdf/view/485882/ESS/ES9018.html,
  
 It is somewhat useful but seems very high level.
  
 I thought that there might be something more detailed out there. I have been studying this recently: 
  
 http://www.customanalogue.com/diy/Stereo_Oppo_Diagram_SMD_Add.gif 
  
 But it doesn't clearly state what all the pins do. Anyway, it's not that important. I was just curious in the event that at some later point I might want to try some things out.
  
 Thanks as always for the response.


----------



## b0bb

penguin140369 said:


> Thanks b0bb.
> 
> I already have the 9018 datasheet:
> 
> ...


 
 The proper datasheet is 35 pages.


----------



## penguin69

Thanks - found it.


----------



## penguin69

b0bb said:


> Post pictures of your LKS and I can take a closer look.
> 
> If the XO has been put on a separate board thinks are easier,


 
  
 As requested, here is a picture of the XO on its dedicated board.
  
 The board has been installed in a small free area on the main board, not too far from the large 6800uF caps, which are to the left, out of picture. The large white wire in the picture runs to where the XO originally sat on the PCB.
  
 This modification should make it easier for me to swop out the XO. I'm not sure if the 14 pin board will help here.  
  

  
  
 I've had the unit a week now, and after sounding pretty raw on day 1, it is slowly starting to improve. Partly due to the the op amp rolling no doubt, and partly perhaps due to the fact that the DAC is still burning-in.


----------



## b0bb

penguin140369 said:


> As requested, here is a picture of the XO on its dedicated board.
> 
> The board has been installed in a small free area on the main board, not too far from the large 6800uF caps, which are to the left, out of picture. The large white wire in the picture runs to where the XO originally sat on the PCB.
> 
> ...


 
  
 One of the nice things in the LKS design is the XO is very close to the DAC.
 LKS very carefully terminated the XO input to the DAC to avoid the signal bouncing back and forth between the DAC input and the XO output.
 In the LKS it is complicated as the signal in split 2 ways.
  
 Below is the XO termination in the LKS.

  
 Adding a coax cable between the XO and the DAC input changes the relationship, the coax cable capacitance adds a delay that is not constant across the frequency band and this distorts the shape of the square wave coming out of the XO, this affects the performance of the Digital PLL in the DAC.
  
 The extra wire also changes the impedance due to the capacitance of the cable, the CCHD-575 is specified to drive only up to 15pF of load and that is not a lot.
 The impedance is now mismatched and you will get reflection, this worsens the jitter performance of the XO.
  
 This might explain why you are hearing a very harsh output out of the DAC.
  
 Here is an example of remote clock line done correctly in the Gustard X20u, the rectangle in green is the line driver to handle the extra load from the coax cable capacitance.

  
 The EE Minimax Supreme also places the clock very close to the DAC

  
 The stock LT1763 regulator noise is specified at 20uV over 10Hz-100kHz. This gives a noise density of 63nV/√Hz
 https://cds.linear.com/docs/en/datasheet/1763fh.pdf
  
 Check that Effective Audiomod regulator you are using is better than this number otherwise return to using the stock regulator.
 Early numbers from DIYAudio suggest the noise is 1mV over 250kHz, this gives a noise density of 2000nV/√Hz
 http://www.diyaudio.com/forums/digital-source/84495-effective-audio-clock-singapore-4.html#post983797


----------



## penguin69

All great information, thanks b0bb.
  
 If I take away the auxiliary board and return to the stock topology, then I can use the 14 pin socket approach and try out different XO's, which would be great.
  
 I read earlier that you need SMT rework tools to remove the XO in the first place, to prevent warping of the PCB. Obviously, the Crystek XO is out now, but is a similar approach required to install the 14 pin socket? I would need to order proper tools, and probably work up the confidence to remove the whole PCB also. Not impossible of course, but as a neophyte modder I'm just looking at the worst case scenario of me rendering useless a $1500 DAC.
  
 I also took a look at the different XO's available. Here in the UK, it's not so easy to get some of these. Maybe I will start with the Crystek 950 as it's affordable and easy to source. Perhaps I am doing something wrong, but my search for the Pulsar XCXO came back with a price of around $400.
  
 Thanks again.


----------



## b0bb

penguin140369 said:


> I read earlier that you need SMT rework tools to remove the XO in the first place, to prevent warping of the PCB. Obviously, the Crystek XO is out now, but is a similar approach required to install the 14 pin socket? I would need to order proper tools, and probably work up the confidence to remove the whole PCB also. Not impossible of course, but as a neophyte modder I'm just looking at the worst case scenario of me rendering useless a $1500 DAC.
> 
> I also took a look at the different XO's available. Here in the UK, it's not so easy to get some of these. Maybe I will start with the Crystek 950 as it's affordable and easy to source. Perhaps I am doing something wrong, but my search for the Pulsar XCXO came back with a price of around $400.


 
 The 14pin socket can be soldered using a conventional iron, post a picture of the area of the XO where the white wire is soldered in to be absolutely sure.
 You will need an adaptor for the SMT crystals like the CCHD950. Twisted pear make them.
  
 The one in the pictures below is made by Accutek Micro.

  

  
  
  
 Key to the soldering exercise is to practice soldering/desoldering on scrap electronics boards, the local electronics recycling centre or local electronics and computer surplus stores is a first starting point.
  
 Proper tools are important, try avoiding the cheap $99 specials on Ebay and elsewhere.
 In my tool inventory Hakko and Metcal make the mid-range gear, on the top end Pace and JBC make excellent  SMT rework, soldering and desoldering tools.
  
 Pulsar is the top of the line XO for the LKS and the price is correct, Crystek 950 is a sane starting point.


----------



## penguin69

Thanks again for the sage advice. I've ordered some better soldering kit, I'll now try to source the oscillator and adapters. I'll leave the more expensive Pulsar xo until I can trust my own handywork a little more. 
  

   


b0bb said:


> The 14pin socket can be soldered using a conventional iron, post a picture of the area of the XO where the white wire is soldered in to be absolutely sure.


 
  

  
 Here's a pic of the board sans XO.


----------



## penguin69

Ok, so earlier today I ordered the 14 pin DIP (the one with the unused pins removed, of course). The part cost 0.90 GBP - nice and cheap. But the postage was 13x the cost of the part.   
  
 So I ordered 10 pieces, just to make the postage cost not seem so rough. I think my LKS cost about the same in shipping...
  
 It seems not that easy to source single instances of XO's over here in the UK. The best bet in terms of availability - and fit - looks like the Abracon AOCJY1. I was about to pull the trigger on this XO through digikey, but I saw that there are several variations, e.g. Sine Wave vs CMOS, 3.3v vs 5v, frequency stability differences, etc. I think there are about a dozen variations in all.
  
 b0bb, I see from an earlier post that the one you have is marked: *AOCJY1   100.0Mhz  C5C*
  
 (I will assume that the fc=10.00MHz allocation to this OCXO in post #279 is a typo.)
  
 I've noted also in an earlier post that you describe the one you use as rated at +/-50ppb for frequency stability. This narows down the options to four:
  
http://www.digikey.co.uk/product-detail/en/abracon-llc/AOCJY1-100.000MHZ/535-10656-ND/2441422
  
http://www.digikey.co.uk/product-detail/en/abracon-llc/AOCJY1A-100.000MHZ/535-10660-ND/2441426
  
http://www.digikey.co.uk/product-detail/en/abracon-llc/AOCJY1-100.000MHZ-SW/AOCJY1-100.000MHZ-SW-ND/5054802
  
http://www.digikey.co.uk/product-detail/en/abracon-llc/AOCJY1A-100.000MHZ-SW/AOCJY1A-100.000MHZ-SW-ND/5054840
  
 I'm guessing it should be the 3.3v model, which would then narrow the options down to 2 - Sine Wave vs CMOS.
  
 I will see if I can work out which it is - they aren't that cheap so I don't want to spend money on the wrong item. I'm pretty sure it shouldn't be the Sine Wave one.


----------



## b0bb

Mouser UK has 21pcs of the CCHD950X
 http://www.mouser.co.uk/ProductDetail/Crystek/CCHD-950X-25-100000/?qs=%2fha2pyFadugYon81AJBUAqtnwa0B0zdCsX3YXApBu6M%3d
  
 The phase noise for the AOCJY1 is for 10MHz, Abracon did not provide any data for 100MHz.
 This is an OCXO that requires special handling, not recomended as a starter device.


----------



## penguin69

Thanks b0bb - I was favoring the Abracon largely because the fit seemed nicely compatible for the DIP adapter. I'll avoid it based on your advice.
  
 I'll order the CCHD950X now. I very nearly ordered it from mouser before, I only held back because I was struggling to locally source the additional adapter board which you recommended.
  
 If I can't easily get that, I'll get it to work by other means.


----------



## penguin69

b0bb said:


> The 14pin socket can be soldered using a conventional iron, post a picture of the area of the XO where the white wire is soldered in to be absolutely sure.
> You will need an adaptor for the SMT crystals like the CCHD950. Twisted pear make them.
> 
> The one in the pictures below is made by Accutek Micro.


 
  
 HI again b0bb,
  
 I found the Accutek adaptors, but the company don't appear to have an online store - did you source yours from them by e-mail?
  
 The Twisted Pear Audio site shows no sign of xo adaptors (unless I'm missing something).
  
 http://twistedpearaudio.com/landing.aspx​
  
 Sorry to be a pain. I thought it might be somewhat easier to source these items. Are there so few DIY'ers out there?
  
 On a separate note, do you have a preferred front end for your LKS? I used a Raspberry Pi with MPD for about 3 years, running the USB out into a cheap PCM2704 converter and then optical into my old DAC (another older EE Minimax). I loved the fact it could play lossless with just 2% CPU usage, and I could leave it running for months without crashing. I recently switched to a Mac Mini for ease of use with Tidal, and so the connectivity is now via USB. For some reason I miss Toslink; I always found it sounded great despite the reported jitter issues with Toslink tranceivers.


----------



## penguin69

I cooked my Dexa op amps yesterday by mistake, so installed on the output stage the old Burson duals which came as an add-on with a previous DAC. They sound pretty good. They are too tall to fit the LKS unit with its lid on.


----------



## b0bb

http://twistedpearaudio.com/digital/cronus.aspx


penguin140369 said:


> HI again b0bb,
> 
> I found the Accutek adaptors, but the company don't appear to have an online store - did you source yours from them by e-mail?
> 
> ...


 
  
 Contact Accutek directly, the boards are made to order, takes about 2 weeks.
  
 The part is 4 Pin SOJ Crystal to 4 Pin(14 Pin Full Size) 300 MIL DIP AK14D300-XTAL-04SOJ

  
 Twisted Pear's adapter is the Rhea, scroll down towards the end of the page
 http://twistedpearaudio.com/digital/cronus.aspx
  
 I use the Logitech Music server (LMS) and Squeezelite combo.
 Squeezelite is run on the Raspberry Pi2 (Picoreplayer)  and  Odroid C1+ (Max2Play)
  
 Rpi2s on the left  Odroid C1+ on the right, Odroid has the benefit on not sharing the USB with the ethernet, sound quality especially imaging is considerably better


----------



## penguin69

A​bsolutely fab - thanks as ever, b0bb. I'll get these ordered tomorrow.
  
 I miss my RPi's somewhat. My software skills exceed my electronic skills (not difficult), so I had great fun with the Pi: I remember creating a scrolling LCD music track display, which was quite cool so long as you were able to ignore all the wires hanging off the GPIO!


----------



## abartels

b0bb said:


> http://twistedpearaudio.com/digital/cronus.aspx
> 
> 
> penguin140369 said:
> ...




Hi b0bb,

Not using I2S-out anymore? All connected with USB?

Btw, did you order your Pulsar 100mHz directly from Italy? Can you share the pricelevel of those?


Regards,
Alex


----------



## b0bb

abartels said:


> Hi b0bb,
> 
> Not using I2S-out anymore? All connected with USB?
> 
> ...





I use I2S for my Soekris R2R dac, these 3 are for my USB DACs (LKS, Schitt Yggdrasil and Esoteric D500/Breeze USB)

The LKS I2S input lacks the noise filtering, its USB is galvanically isolated and much nicer.

The Pulsar came directly from Italy, there were no discounts, about 400USD shipped.


----------



## abartels

b0bb said:


> abartels said:
> 
> 
> > Hi b0bb,
> ...




What kind of Noise filtering, related to I2S, are you talking about?
Pulsar's are great, suppose you received them taxfree, those are about €450 in Europe  Need two pieces for my FIFO set, maybe a (very) nice Xmas present to myself


----------



## penguin69

b0bb said:


> The 14pin socket can be soldered using a conventional iron, post a picture of the area of the XO where the white wire is soldered in to be absolutely sure.
> You will need an adaptor for the SMT crystals like the CCHD950. Twisted pear make them.
> 
> The one in the pictures below is made by Accutek Micro.
> ...


 
  
 Hi,
  
 My Crystek 950 delivery has arrived - just waiting on the adapter board deliveries now.
  
 I notice that the Crystek XO has no pins. I'm a little worred that, because of the lack of pins, it may be a little harder to solder the XO to the Twisted Pear adapter board, and as a ham-fisted neophyte I could easily cook the XO. Any tips here? Solder at as low a temperature as possible, with minimum contact time, perhaps.
  
 A second challenge is that one of the 4 gold-coloured 'washers' on the LKS board has come away after I de-soldered the cable modification (see picture below of the cable before removal). I assume it is ok to solder instead to the inner raised contact to its left? This makes life a little harder when it comes to using the 14 pin reusable adapter, but I figure it's a price worth paying as I don't fancy my chances of getting the washer repair correct.
  
 Or maybe I can attempt the repair, and if the DAC returns silence (i.e. XO not working), then I should try soldering to the raised contact ...
  
 As an aside, I have left the lower cable in situ for the time being, I am guessing it is just drawing power for the XO modification board in the bottom right of the pic.


----------



## penguin69

And, looking at the traces in the diagram above and in relation to the Crystek datasheet, it seems to me that:
  
 - Top Right contact is the XO OUT, running to the resistors above and then to what I assume is Pin 24 (XI) on each ES9018.
 - Bottom Right contact is GND.
 - Top Left contact is 3.3v supply.
 - Bottom Left contact not used?
  
 (sorry if my terminology is rubbish.)


----------



## b0bb

abartels said:


> What kind of Noise filtering, related to I2S, are you talking about?
> Pulsar's are great, suppose you received them taxfree, those are about €450 in Europe
> 
> 
> ...


 
  
 Ceramic feedthru caps on the I2S lines, this limits the rise-time of the pulses reducing RF noise. CF3-CF8 on the example diagram.
  

  
  
 You can just buy one Pulsar first and see if you like it, suggest the clock for the 44.1kHz stream as it is more common.


----------



## b0bb

penguin140369 said:


> And, looking at the traces in the diagram above and in relation to the Crystek datasheet, it seems to me that:
> 
> - Top Right contact is the XO OUT, running to the resistors above and then to what I assume is Pin 24 (XI) on each ES9018.
> - Bottom Right contact is GND.
> ...


 

 That looks right.


----------



## b0bb

penguin140369 said:


> Hi,
> 
> My Crystek 950 delivery has arrived - just waiting on the adapter board deliveries now.
> 
> ...


 
  
 Leave the cable in place.
  
 The washer (proper name pcb land) can be easily fixed, repair kits are available, example below is about 33USD.
 http://www.all-spec.com/Catalog/Soldering-Rework/PCB-Board-Assembly-and-Repair/Circuit-Board-Assembly-Repair-Kits/CP090100AS-10123#

  
 To avoid future overheating problems preheat the board first and use a fine tip iron.
 Low cost hot-air wands is the tool of choice.
 http://yihua-soldering.com/product-3-3-4-hot-air-rework-station.html/158746
  

  
 Use the same method for the XO, tape down the XO to the adapter and warm it up, use heat resistant tape like kapton (the transparent golden tape around my Pulsar XO)
  
 Apply rosin flux to both the XO and adaptor PCB lands, the  soldering operation should only take 1-2 seconds if the XO and board is adequately warmed up.
 I use an air temp setting of 120-125 degC.
  
 NOTE: The wand must always be constantly moving across the work piece to avoid hotspots.
  
 MG chemicals makes a good Rosin flux pen
 http://www.all-spec.com/Catalog/Soldering-Rework/Soldering-Chemicals/Flux-Pens/835P-1695?gclid=CLn13JL-g88CFQVbfgodtLYCeA


----------



## abartels

b0bb said:


> abartels said:
> 
> 
> > What kind of Noise filtering, related to I2S, are you talking about?
> ...


 
  
 Thanks for clarification b0bb, not sure if my dac pcb uses these murata emi rfi smd filters, it's probably wise to inspect, and if not in-designed, trying to modify circuitry with them.
  
 The pulsar's aren't available right now in the frequencies I need, btw, I still can use 45.1584 mHz and  49.152 mHz tcxo's instead of 22.5792 mHz and 24.576 mHz inspite of the table showed in AK4495SEQ datasheet!
 This is very strange.... I tested sample frequencies up to 768 kHz and they all work flawlessly. Strange they mention this in their white papers


----------



## penguin69

b0bb said:


> Leave the cable in place.
> 
> The washer (proper name pcb land) can be easily fixed, repair kits are available, example below is about 33USD.
> http://www.all-spec.com/Catalog/Soldering-Rework/PCB-Board-Assembly-and-Repair/Circuit-Board-Assembly-Repair-Kits/CP090100AS-10123#
> ...


 
  
 Many thanks as ever, b0bb.
  
 As it happens, I already ordered an air-wand very similar to the one above, it arrived a couple of days ago. The instruction manual is appalling but the tool itself looks good and is mostly intuitive.
  
 I will order the Rosin flux pen.
  
 I got impatient and connected the Crystek XO to the LKS using some bread-board jumper leads (sub-optimal of course, but I wanted to get started). The LKS Audio DAC is now listenable, even in this configuration. Previously, I could not listen to the DAC at all without becoming irritated with the seemingly brittle, jittery sound.
  
 Tomorrow I may try taking the regulated voltage supply from that small aftermarket board I showed in the picture rather than the PCB rail, to see if there is any difference. If this helps, then for the final configuration I will consider connecting 2 of the XO pins, OUT and GND, directly to the board (via the TwistedPear adapter) but take the voltage supply from the aftermarket regulator board.
  
 If this all goes to plan and I don't screw anything up, then I will be interested to try out some other XO's. The Pulsar is the end game, assuming that it is within my capabilities to use it.
  
 For the record, I bought 2 Crystek 950's, just in case I fry or irretrievably damage one of them!
  
 I'm actually a little bit surprised that the Crystek works with the jumper leads, given they are about 3 inches long.


----------



## b0bb

penguin140369 said:


> I'm actually a little bit surprised that the Crystek works with the jumper leads, given they are about 3 inches long.


 
 That is OK during the process of bring-up, to get the max performance (lowest jitter etc) it needs to be as close to the DAC as possible.
  
 You have an radio transmitting antenna there, the XO operating at 100MHz is just below the top of the FM radio band (108MHz), keep an eye on the radio interference.


----------



## penguin69

No updates from me so far as I am still waiting on parts to arrive. Once the Twisted Pear adapter board arrives I will install the new clock properly.
  
 On a clock-related note, is there a preferred DPLL setting of the nine on offer? I currently have AUTO as the setting. FWIW, I listen mostly to Tidal and my own 44.1 redbook rips (.wav).


----------



## b0bb

penguin140369 said:


> On a clock-related note, is there a preferred DPLL setting of the nine on offer? I currently have AUTO as the setting. FWIW, I listen mostly to Tidal and my own 44.1 redbook rips (.wav).


 
 On material with 44.1kHz sampling any setting can be used, start with the lowest setting compare it to AUTO, you might like the sound, which has a fuller body in the midrange at the expense of the spatial presentation, that is to say a little more fuzzy with loss of image placement on the downside by a much sweeter midrange on the upside.
  
 If you have DSD or high sampled PCM material of 192kHz and above, the AUTO setting is best, the sound drops out at the lower settings


----------



## penguin69

b0bb said:


> On material with 44.1kHz sampling any setting can be used, start with the lowest setting compare it to AUTO, you might like the sound, which has a fuller body in the midrange at the expense of the spatial presentation, that is to say a little more fuzzy with loss of image placement on the downside by a much sweeter midrange on the upside.
> 
> If you have DSD or high sampled PCM material of 192kHz and above, the AUTO setting is best, the sound drops out at the lower settings


 

 Thanks b0bb, I'll try that out. I listen almost exclusively to 44.1khz material.
  
 I'm still waiting on the Twisted Pear adaptor board to arrive so that I can get rid of my RFI aerials (jump leads).
  
 I got bored today with the inactivity so I re-wired the Crystek 950 XO to take its feed from the aftermarket regulator board. The sound is still good, arguably it is a little larger and more airy than it was - although any change is subtler than the step change of swapping out the 575 XO (which incidentally seems to work ok on the EE Supreme).
  
 I've ordered the Ticha 994 op amps for the I/V section, let's hope that they don't take as long as the Twisted Pear board is taking.
  
 Once everything I have ordered is in place, I will work backwards through the thread and see what I should next focus on. My soldering/desoldering is getting better, aided by a decent magnifying glass and a reasonbly good quality temperature controlled iron with a fine tip.


----------



## Tomus4

Hi b0bb,
  
 Did you checked Burson v5 in the I/V circut?


----------



## penguin69

tomus4 said:


> Hi b0bb,
> 
> Did you checked Burson v5 in the I/V circut?


 

 I'm fairly sure that b0bb posted earlier in this thread that Burson had told him that the v5 should not be used in the I/V section.


----------



## Tomus4

Do you know why? I have response from Burson:
Hi Thomasz,
 
Thank you for your email and your interest in our audio opamps.
 
For the LKS, V5 is the best.  Our V5 and V5i both can work in the i/v stage.   No problems. 
 
Best regards,
 
Alex
    *Burson Audio*| www.BursonAudio.com | info@bursonaudio.com 
*Supreme Sound Audio*| www.SSAudio.com.au | opamp@bursonaudio.com


----------



## penguin69

Ah - maybe I mis-remembered. I thought b0bb said the v5i's weren't suitable.
  
 FWIW, I've got v4 Bursons in the output stage of the LKS - they also sound good.


----------



## Tomus4

I'am thinking about v4 too. It seems to have better parameters then v5. And becouse it have 40mA Quiescent Current vs 30 mA Ticha it might be good for I/V. 
 On  the one side I have seen opinion that v5 is the best  - http://www.head-fi.org/t/784790/burson-supreme-sound-audio-v5-opa-d-v5-opa-s-review and above Burson sales suggestion. On the other side my country Burson's dealer and parameters (Open-loop gain (dB), 
 Common-Mode Rejection Ratio, Total Harmonic Distortion) point v4 is better.


----------



## b0bb

Originally Posted by *Tomus4* 


  
 Hi b0bb,
  
 Did you checked Burson v5 in the I/V circut? 
  
  
 Yes.
  
 The soundstage shrank and the top end extension and spaciousness was gone giving a darker, more veiled presentation.
  
 The ES9018 needs to have compensation capacitance added across the I/V resistor to counteract the capacitance at the opamp input.
 This is the DAC output capacitance + the opamp input capacitance.
  
 The stock opamp used in the LKS (OPA1612) and the Ticha 994 have input capacitances of 8pf and 6pf respectively, this makes a very straight forward swap.
  
 The Burson V5 on the other hand, has a FET input, typical capacitance is between 2X-5X higher, this means the default 220pF compensation cap has to be adjusted.


----------



## b0bb

penguin140369 said:


> Ah - maybe I mis-remembered. I thought b0bb said the v5i's weren't suitable.
> 
> FWIW, I've got v4 Bursons in the output stage of the LKS - they also sound good.


 

 There were 2 versions.
 The recommendation from Burson for the older version with yellow base was to not use it in the I/V converter position.
  
 The newer one with the black base sounded better and Burson told me it has incremental improvements, that one did not have issue with working as the I/V converter.
  
 Sound quality wise the 994 was better  but this could possibly be fixed.


----------



## Tomus4

Thank you very much for response b0bb.
 What do you thing about Burson v4 ? Did you checked it in RCA and I/V section?


----------



## penguin69

So the Crystek 950 is now in situ, with the Twisted Pear adaptor board underneath it, and the 14 pin DIP adaptor below it.

The task was less than straightforward as the original soldering for the external XO board had caused the PCB land to come free, and I wasn't confident that I could replace it and ensure a decent contact with the PCB. I also needed to truncate the top left pin of the 14 pin adaptor so that it did not make contact with the 'voltage in' PCB land, as I wanted to avail of the regulated voltage output from the board in the bottom right of the picture.

It's no oil painting, but everything seems to work ok. I'm kind of surprised that I didn't screw something up or irrepairarably damage a component. I'll do some extended listening tomorrow and assess the improvements.

I'd like to put the lid on the LKS temporarily in order to keep animals away from my handiwork (and the 240v AC, which I doubt is good for their fur). However, I am a little concerned that the jump lead providing the regulated voltage to the Vin pin may work loose. 

If it does come free, then I assume the DAC will let me know by going silent as soon as it detects no input on PIN 24. Is this correct?


----------



## b0bb

penguin140369 said:


> I'd like to put the lid on the LKS temporarily in order to keep animals away from my handiwork (and the 240v AC, which I doubt is good for their fur). However, I am a little concerned that the jump lead providing the regulated voltage to the Vin pin may work loose.
> 
> If it does come free, then I assume the DAC will let me know by going silent as soon as it detects no input on PIN 24. Is this correct?


 
 The jump lead carrying power should be secured, it can do a lot of damage if the lead touches anything else on the motherboard.


----------



## b0bb

tomus4 said:


> Thank you very much for response b0bb.
> What do you thing about Burson v4 ? Did you checked it in RCA and I/V section?


 

 I do not have the V4 and would probably used something like this in the RCA section only.


----------



## penguin69

b0bb said:


> The jump lead carrying power should be secured, it can do a lot of damage if the lead touches anything else on the motherboard.


 

 Okay, noted b0bb - I'll find a small adapter which secures it. It's tensioned to spring upward at the moment, so I've kept the lid off.
  
 Thanks again for all the help. It would never have occurred to me to swap out the stock XO to improve the sound. Really, the LKS was brittle and thin to listen when I first got it - I couldn't stand it. Now it's smooth and detailed.
  
 The Ticha's are due any day for the I/V section. Looking forward to those.
  
 Out of curiosity, can the ES9018 operate without a master clock? Probably a stupid question, but if the chip is receiving, say, an S/PDIF signal then it does at least have a (probably jittery) clock source even if it doesn't have a master reference.
  
 The reason I ask is I would like to test how 'bad' the LKS can sound, compared to how good. My thinkinh was I could put a temporary switch on the voltage supply to the XO in order to test this. I did try this manually about a week ago (I simply unsoldered the supply) but I lost all sound. And whilst I understand how S/PDIF works, I unfortunately have little idea how the Amanero board feeds a signal to the Sabre DACs.


----------



## b0bb

penguin140369 said:


> Out of curiosity, can the ES9018 operate without a master clock?


 
  
 The 9018 requires the use of a master clock.


----------



## Coolzo

ufokillerz said:


> Out of curiosity, has anyone compared this to something like the gustard x20u?
> I have a x20u, but am considering this unit.




I am also curious about this. Seriously considering either one or the other.


----------



## justbenice

Hi B0bb, 
 Are there anyway to reduce the supply voltage for the opamps in the output stage ? I tried 2 blue trimpot but it doesn't work.


----------



## b0bb

justbenice said:


> Hi B0bb,
> Are there anyway to reduce the supply voltage for the opamps in the output stage ? I tried 2 blue trimpot but it doesn't work.


 

 There 4 trimpots, 2 by the regulators and 2 near the dac, which ones did you try?


----------



## penguin69

LKS mod update:
  
 XO upgraded: *Crystek 950*
 Output op amps upgraded: *Burson* *double-sided discretes*
 I/V op amps upgraded: *Ticha* *994's*
  
 All sounding very good now. Far better than when I first acquired the LKS and listened to it for the first time (that was a very disappointing day).
  
 Wondering what to focus on next in the upgrade path?


----------



## b0bb

penguin140369 said:


> LKS mod update:
> 
> XO upgraded: *Crystek 950*
> Output op amps upgraded: *Burson* *double-sided discretes*
> ...


 

 There are a couple of options.
  
 1)Replace the I/V resistors with Vishay TX-2575 Z-Foil  Metal foil resistors, 4 pcs needed.
 Texas Components make these to order for about 10-15 USD each. I am using 0.005% tolerance, the gain of the I/V stage is purely detemined by the I/V resistor, the closer the match the lower is the distortion from the I/V conversion.
 The temp coefficient is ±1 ppm/°C, the MELF metal film that is stock is ±100 ppm/°C

  

  
 2) Replace the bypass cap for Vcom. The existing electrolytic cap's leakage current is quite large, replace this with a low leakage cap like the yellow Tantalum bead cap shown in the above picture.
  
 The stock 100uF Panasonic FM aluminum electrolytic cap has a leakage of 10μA, the Tantalum bead is 0.5μA
 Th total current in the Vcom reference is 100μA, so there is a 10% error from cap leakage with the stock cap.
  
 Leakage current from electrolytic caps can vary wildly with temperature and the applied voltage, less so with Tantalum caps.
  
 3)Replace the Vcom trimpot with a Vishay Accutrim metal foil trimmer, these have very low temperature drift ±10ppm/°C, the stock Bourns has a temp coefficient of ±100ppm/°C.
  
 Vcom is the voltage reference for the D/A conversion, so a lot of things depend on this being  as stable and as low noise as possible.
  
 4)The stock rectifiers can be replaced with low noise Schotttky types.


----------



## dacusb

Hi B0bb,
  
 Can you help by giving me the link where to get the Tantalum bead 0.5μA?
 Thanking you.


----------



## penguin69

b0bb said:


> There are a couple of options.
> ...




Thanks b0bb. These were the areas I was considering based on a re-read of the whole thread.

I'm actually pretty happy with the sound now. But that is no reason to stop.


----------



## b0bb

dacusb said:


> Hi B0bb,
> 
> Can you help by giving me the link where to get the Tantalum bead 0.5μA?
> Thanking you.


 
 http://www.mouser.com/ProductDetail/Vishay-Sprague/199D107X9020F6V1E3/?qs=sGAEpiMZZMtZ1n0r9vR22R37xUugJl7tUjm7LYm%2fbeA%3d
  
 100uF 20V tantalum bead.
 7μA with 20V across the cap, this drops 10-15x (0.70-0.45μA) with 1V across the cap


----------



## dacusb

Hi B0bb,
  
 Thank you for your reply. I will continue to upgrade my LKS accordingly.
 I have the following problems using Singxer SU-1 and connect it to the LKS MH DA 003.
 I connect the Singxer SU-1 to my LKS MH DA003 using HDMI/I2S ports. The setting on SU-1 is: Pin 2 and Pin 6-7 set to ‘on’. This works fine with PCM modes but become surprisingly unpleasant when I upsample music files (FLAC/WAV) to DSD modes using JRiver: the music from the left channel is switched to the right channel and vice versa (recently it seems that the sound becomes monophonic) There is also a loud “pop’ at the beginning/end of the song when I stop and re-start the music. How can I fix those problems?
 I am very disappointed when Shenzhen Audio explained that is because of the LKS and not the Singxer and even suggested that I should replace the LKS using the Gustard X20 or PS audio dac instead which is ridiculous.


----------



## b0bb

dacusb said:


> Hi B0bb,
> 
> Thank you for your reply. I will continue to upgrade my LKS accordingly.
> I have the following problems using Singxer SU-1 and connect it to the LKS MH DA 003.
> ...


 
 Your SU-1 is configured to connected to the Gustard X20.
 In DSD mode the Gustard expects the I2S channel mapping of the left and right channels to be reversed  as you have noted.
 This might be why the vendor is taking advantage of the situation to sell you the X20
  
  
 The bank of DIP switches can change the behavior of the SU-1 to make it compatible with the LKS, contact Singxer directly for the info on how to set it up .
 LKS I2S channel mapping mode is the same in PCM and DSD.
  
 http://www.singxer.com/contact.jsp
  
 Ask Singxer about the pop at the beginning and end of the song, one reason is the I2S clock being started and stopped, keeping it on all the time might fix things.
 Singxer might be able to give you more info.


----------



## dacusb

Thank you B0bb for your guidance. I will contact Singxer directly and will keep you posted about the progress.


----------



## justbenice

b0bb said:


> There 4 trimpots, 2 by the regulators and 2 near the dac, which ones did you try?


 
 Hi friend !
 I tried 2 trimpots near the Ticha opamps.


----------



## b0bb

justbenice said:


> Hi friend !
> I tried 2 trimpots near the Ticha opamps.


 

 These trimpots adjust the DC offset/reference and not the supply voltage, you will need to reset the DC offset on the DAC
 Recheck the DC offset by measuring the voltage on pins 1 and 2 on the XLR connector and adjust the trimpot to as close to 0 Volts DC as possible.
 Turn the DAC off after doing that to finish the reset.
  
 The trimpots near the regulator are the ones that adjust the output voltage.


----------



## justbenice

b0bb said:


> These trimpots adjust the DC offset/reference and not the supply voltage, you will need to reset the DC offset on the DAC
> Recheck the DC offset by measuring the voltage on pins 1 and 2 on the XLR connector and adjust the trimpot to as close to 0 Volts DC as possible.
> Turn the DAC off after doing that to finish the reset.
> 
> The trimpots near the regulator are the ones that adjust the output voltage.


 
  
 You are alway very helpfull  Thank you !


----------



## kazcou

A mini version of this DAC (LKS MH-003 MINI)


----------



## dacusb

Dear B0bb,
  
 I went to mouser website and tried to find the correct Wima film capacitors MKP2, but the mouser page said there are 4 or 5 different ones and I have to select the right ones.
  
 http://www.mouser.vn/WIMA/Passive-Components/Capacitors/Film-Capacitors/_/N-9x371?P=1z0wq52Z1yvq1jiZ1z0zldhZ1z0yl9vZ1z0yl9t&FS=True
  
 Can you specify which ones is correct and how many of them i would need.
 It seems not easy to mount them on the 4-layer board. Can you be more specific?
 Thank you for your guidance.


----------



## b0bb

dacusb said:


> Dear B0bb,
> 
> I went to mouser website and tried to find the correct Wima film capacitors MKP2, but the mouser page said there are 4 or 5 different ones and I have to select the right ones.
> 
> ...


 

 8pcs of the following. The 63V ones are smaller but Mouser does not have those in stock.
 http://www.mouser.vn/ProductDetail/WIMA/MKP2D031501H00KC00/?qs=sGAEpiMZZMv1cc3ydrPrF2Av7JKdyW4DCABnugoea9E%3d
  
 NOTE:The existing 0.1uF MKS caps need to be removed, these are next to the Black Panasonic FM caps. On mine the place is re-used by a 100pF Corning CGW glass cap, the square black box.

  
  
 You will need a desoldering iron for removal of the stock caps , solder braid is not recommended due to the large risk of damaging the board.
  
 I mount mine under the board


----------



## dacusb

Hi B0bb,
  
 Thank you for your help and guidance so far.
 As per your recommendations, can I mod by:
 1)Replacing the I/V resistors with Vishay TX-2575 Z-Foil  Metal foil resistors, and leaving the existing Wima caps as they are, unchanged?
  
 2) Replacing the bypass cap by using the  Tantalum bead cap as shown in the picture ?
  
 3)Replacing the Vcom trimpot with a Vishay Accutrim metal foil trimmer?
  
 dacusb


----------



## b0bb

dacusb said:


> Hi B0bb,
> 
> Thank you for your help and guidance so far.
> As per your recommendations, can I mod by:
> ...


 

 These can come after the simpler mods
 1) 100MHz Crystek CCHD-950X XO
 2) Sonic Imagery Ticha 994 discrete opamp for the I/V
 3) Self powered enhanced USB interface with the Crystek CCHD-957 XOs from LKS/Volent


----------



## dacusb

Dear B0bb,
  
 Actually I have been following-up quietly all your posts since the beginning of 2016 and I have done many mods accordingly incl. 100MHz Crystek CCHD-950X XO, replacing the existing IV opamp to Ticha 994, swapping the unbalance opamp to Muses01 etc...
 As I use the Singxer SU-1 USB interface to connect to the LKS using both AES and HDMI/I2S ports, hence I do not touch to the USB part of the LKS.
 It is time to think of some further mods, but to tell the truth I am very reluctant to replace the Wima caps. Will it be OK if I bypass the Wima caps while only replacing the I/V resistors with Vishay TX-2575 Z-Foil Metal foil resistors?
 Thank you for your prompt feedback.


----------



## b0bb

dacusb said:


> It is time to think of some further mods, but to tell the truth I am very reluctant to replace the Wima caps. Will it be OK if I bypass the Wima caps while only replacing the I/V resistors with Vishay TX-2575 Z-Foil Metal foil resistors?


 
 The Vishay Z-foils are relatively easy to add, to go beyond this other components on the board will need replacing


----------



## dacusb

b0bb said:


> 8pcs of the following. The 63V ones are smaller but Mouser does not have those in stock.
> http://www.mouser.vn/ProductDetail/WIMA/MKP2D031501H00KC00/?qs=sGAEpiMZZMv1cc3ydrPrF2Av7JKdyW4DCABnugoea9E%3d
> 
> NOTE:The existing 0.1uF MKS caps need to be removed, these are next to the Black Panasonic FM caps. On mine the place is re-used by a 100pF Corning CGW glass cap, the square black box.
> ...


 
 Hi B0bb,
  
 I have noticed that you have mentioned that the place used for 0.1uF MKS caps is re-used by a 100pF Corning CGW glass cap, the square black box. Can you indicate whether it is necessary to install the 100pF Corning CGW glass cap at this place? If it is, where acn I get the Corning CGW glass cap?
 Many thanks B0bb.


----------



## b0bb

> Originally Posted by *dacusb* /img/forum/go_quote.gif
> where acn I get the Corning CGW glass cap?


 
 Ebay http://www.ebay.com/itm/262657134111.
  
 Normally these are 30-60USD each, the 120pF is close enough.


----------



## Dionis

Hello, I'm from Ukraine.
 B0bb, I admire the work done by you work to improve the LKS Audio MH-DA003 DAC.
 I read the whole thread of this forum, and I have a question that I have not found an answer. I use return only unbalanced output, I set OPA301b amplifiers. To improve the sound to me necessarily to replace operational amplifiers in balanced outputs on Model 994Enh-Ticha Dual Discrete Op Amp.
 For me it is large enough costs $ 200, and whether it will be worth this investment. Or maybe leave standard OPA1612, in the balanced output.


----------



## Dionis

B0bb, and the second question to you, generally correspond to OPA301b their characteristics for signal amplification in class A in unbalanced outputs. Here are the detailed characteristics of the op amp http://www.ebay.com/itm/1X-OPA301-MK2-DUAL-AUDIOFEEL-DISCRETE-OP-AMP-Board-Low-Impedance-/282005506216
 Thank you in advance!


----------



## b0bb

dionis said:


> I read the whole thread of this forum, and I have a question that I have not found an answer. I use return only unbalanced output, I set OPA301b amplifiers. To improve the sound to me necessarily to replace operational amplifiers in balanced outputs on Model 994Enh-Ticha Dual Discrete Op Amp.
> For me it is large enough costs $ 200, and whether it will be worth this investment. Or maybe leave standard OPA1612, in the balanced output.


 
 The 994 is used in the current-voltage converter and is common to both the balanced and unbalanced stage.


----------



## b0bb

dionis said:


> B0bb, and the second question to you, generally correspond to OPA301b their characteristics for signal amplification in class A in unbalanced outputs. Here are the detailed characteristics of the op amp http://www.ebay.com/itm/1X-OPA301-MK2-DUAL-AUDIOFEEL-DISCRETE-OP-AMP-Board-Low-Impedance-/282005506216
> Thank you in advance!


 

 Looks OK for use in the unbalanced stage.


----------



## Dionis

> message from *b0bb* /img/forum/go_quote.gif
> Looks OK for use in the unbalanced stage.


 
 B0bb, I can not properly asked. If I only use the unbalanced output, whether the effect will be on the replacement of the operational amplifiers in a balanced stage (I / V). Or for unbalanced output has an effect on the sound quality is only the operating uilitel.


----------



## b0bb

dionis said:


> B0bb, I can not properly asked. If I only use the unbalanced output, whether the effect will be on the replacement of the operational amplifiers in a balanced stage (I / V). Or for unbalanced output has an effect on the sound quality is only the operating uilitel.


 
 LKS converts the balanced output (U2/U3) to unbalanced to provide the unbalanced output.
 Below is the reference analog stage for the 9018, the unbalanced converter section (U1) is slightly different on the LKS.

  
 The Ticha 994 is used for U2 and U3.


----------



## penguin69

Hi b0bb
  
 I am currently running the LKS in balanced mode, on the rationale that removing a set of op amps from the signal path means one less potential distortion source. The sound is very good indeed. It also helps a little in that my passive preamp seems to have been designed for lower outputs than that provided by the unbalanced output.
  
 I have one question: does the LKS analogue stage architecture expect current draw from the output stage op amps? I have removed these, on the perhaps simplistic presumption that they are not needed.
  
 Thanks in advance.
  
 (ps - my LKS mods will continue shortly, I've just been held up recently with work and a vacation.)


----------



## b0bb

penguin140369 said:


> I have one question: does the LKS analogue stage architecture expect current draw from the output stage op amps? I have removed these, on the perhaps simplistic presumption that they are not needed.


 
  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.


----------



## fjc36

LKS Audio MH-DA003 has model mkII now, that use DAC ES 9028 Pro, any idea of its sonic performance would be? The main clock is still to be the Crystek 82 fs, (575? )that was first thing replaced by 950 here. It is on the market now and the price is rising to RMB 8000. Seems no alteration of the front appearance.


----------



## penguin69

b0bb said:


> 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

abartels said:


> 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

b0bb said:


> abartels said:
> 
> 
> > 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
> ...


 
 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

fjc36 said:


> 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

abartels said:


> 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
> 
> ...


 

 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

penguin140369 said:


> 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

b0bb said:


> abartels said:
> 
> 
> > Hi B0bb,
> ...


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


----------



## b0bb

abartels said:


> 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.


----------



## penguin69

b0bb
  
 Any thoughts on XO's from bliley?
  
 http://www.bliley.com/​
  
 Needless to say, I don't have the skills to understand whether their kit is good or not, however I do like the enthusiasm and educational material they provide on XO's.


----------



## b0bb

penguin140369 said:


> b0bb
> 
> Any thoughts on XO's from bliley?
> 
> ...


 

 Looked at their product range when I compiled my list of XOs , did not see anything for the LKS that I found interesting.


----------



## fjc36

Dear Bobb,
  
 It is not fair, but I still like to ask a stupid question. It seems to me, LKS release the next version of MH-DA003, the MKII, preserve main XO, the I/ V OP, diodes, and many other items. They or their R & D engineers must read this forum and made some test. What would you think the sound may vastly improved just because use a ESS 9028pro ? If not so, I must say, the east and the west do have different ear structure or ideal for a good Hi-Fi sound. Your comment ?
 My idea is it should still sound harsh if nothing except switch the DSC chip to a higher level, because there is no magic solution. So sturboon, this time? Or they disagree everything in the very beginning. Your comment.


----------



## b0bb

fjc36 said:


> Dear Bobb,
> 
> It is not fair, but I still like to ask a stupid question. It seems to me, LKS release the next version of MH-DA003, the MKII, preserve main XO, the I/ V OP, diodes, and many other items. They or their R & D engineers must read this forum and made some test. What would you think the sound may vastly improved just because use a ESS 9028pro ? If not so, I must say, the east and the west do have different ear structure or ideal for a good Hi-Fi sound. Your comment ?
> My idea is it should still sound harsh if nothing except switch the DSC chip to a higher level, because there is no magic solution. So sturboon, this time? Or they disagree everything in the very beginning. Your comment.


 

 9028Pro is designed to drop in to boards made for the existing 9018S, how well that will work is an open question.


----------



## fjc36

There is one Canada exasound  ES9028pro  USB DAC on the market, cost around US$ 2500-3000., more expansive than the $1300 on LKS MH-DA003 I think. Sound quality?
 see 
  http://www.exasound.com/StartHere/exaSoundDACs-Features.aspx
 It has no internal power section, something good or inconvenient?


----------



## -Felix-

fjc36 said:


> 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.


 
  
 Interesting! Unfortunately, the link is not working for me. But I found these links:
 http://www.shenzhenaudio.com/l-k-s-audio-mh-da003-mk2-es9028pro-dac-usb-dsd-femto-clock-110v-to-250v.html
 http://www.shenzhenaudio.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/_/-/_-14_3_1.jpg
 https://translate.google.de/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%2Fwww.hiendy.com%2F%3Fp%3D8226
 http://www.hiendy.com/hififorum/data/attachment/forum/201611/02/145052hd4oa74klfanglad.jpg
  
 What I can guess from the low-res images is that the pcb itself is completely unchanged, the power sections look unchanged (components could be replaced by others with similar appearance), the right digital section seems unchanged too (option for the new USB module), however, there are minor changes regarding the caps on the left side next to the ES9028pros, two caps missing in the I/V sections (?!) and also four red WIMA caps replaced by green (WIMA?) caps in the next opamp sections.
  
 Inspired by b0bb's modifications?


----------



## Ric Schultz

Here are some of my thoughts on the output stage:
  
 Usually less is better.  If the schematic is similar to the one B0bb showed then I think the sound is being compromised.  The filter parts and the summing op amp are compromising the sound of the balanced outs.  If you are using the balanced outs then remove the summing op amps and all the resistors and caps to ground in its circuit.  Then I would remove most of the output filters from the balanced outs.  You can simply use a 100 ohm resistor directly from the IV converter to the output jack pins.....nothing else.  You create a single pole filter by placing an appropriate sized cap across the feedback resistor in the IV circuit.  The IV stage can drive a cable directly without problem.  I have been doing this for years and years.  The output current that the IV converter would be using to drive a cable is practically nothing.  2 volts rms divided by say a 10K load is two tenths of a milliamp.....The IV converter has no problem with this.
  
 If you are using unbalanced out then just use the positive phase output from the IV converter and don't use the negative phase.  Summing circuits all wreck the sound.  This is my direct experience for years. Probably no one will try any of this and that is fine.  Just letting you know my experience.  I may get one of the new 9028 ones in here and if I do and do these mods then I will let you know what I experience.  Have fun.


----------



## fjc36

Dear Ric, 
 Happy to see and anxious to read your findings at the LKS da003 with the ES 9028pro on it.


----------



## fjc36

Flix, What a good observation, I have corresponded to the sales. Yes, there is no change on the circuitry. Few minor changes on the caps. Hidden firmware is rewrited for operation. No change on the power supply. They may have a 9038pro edition next year. For buying now, because at  the Nov 11 event (1111 meaning for singles fair in Tao Bao sells), they may have a small discount,(up to 10%) now.


----------



## penguin69

ric schultz said:


> Here are some of my thoughts on the output stage:
> 
> Usually less is better.  If the schematic is similar to the one B0bb showed then I think the sound is being compromised.  The filter parts and the summing op amp are compromising the sound of the balanced outs.  If you are using the balanced outs then remove the summing op amps and all the resistors and caps to ground in its circuit.  Then I would remove most of the output filters from the balanced outs.  You can simply use a 100 ohm resistor directly from the IV converter to the output jack pins.....nothing else.  You create a single pole filter by placing an appropriate sized cap across the feedback resistor in the IV circuit.  The IV stage can drive a cable directly without problem.  I have been doing this for years and years.  The output current that the IV converter would be using to drive a cable is practically nothing.  2 volts rms divided by say a 10K load is two tenths of a milliamp.....The IV converter has no problem with this.


 

 I am currently running my MH-DA003 with the stock output stage op amps removed, and Ticha 994 I/V's feeding the balanced out. I doubt I will change this approach as the balanced sound is so good.
  
 It has also saves me a few quid (dollars) insofar as I don't need to purchase an extra pair of discrete op amps.
  
 I am impressed at how (with expert and extremely generous guidance from b0bb) I have been able to change the sound of this unit from average at best to extremely good.
  
 I wll be working to make more changes shortly. My technical knowledge of these areas is improving slowly, but I'm still not at a stage where I can make autonomous decisions. (I wish I had studied EE rather than computing at college all those years ago.   )


----------



## Ric Schultz

To make this more clear for balanced users:  What I am saying is that the balanced outs would sound better if you got rid of the summing op amp and ALL its filter parts AND you remove all excess filters from the output of the balanced outs and just use a 50-100 ohm resistor directly to the output jacks from the IV converter.  I understand that most people would not have the ability to do this as it is not just a parts swap.  Anyone can remove the summing op amps, if not in use.  However, there are still parts to ground affecting the sound in its circuit that should be removed for best sound.


----------



## 0t73r

I've found instruction to change the usb module seem you can use unused output from LKS transformer. Instruction http://pan.baidu.com/s/1pJ7izLT . Is there a disadvantage if I just use this without using separate transformer?
  
 EDITED: Apologize, read through earlier thread and found my answer.


----------



## gaddabout

dacusb said:


> Hi B0bb,
> 
> Thank you for your reply. I will continue to upgrade my LKS accordingly.
> I have the following problems using Singxer SU-1 and connect it to the LKS MH DA 003.
> ...


 
  
 That's what i experience too...and i'm glad to read that i'm not alone: i use the gustard U12 with the LKS HDMI/I2S port...native DSD mode gives me mono output  and a blop at the beginning. i use luckit drivers for the gustard u12...


----------



## 0t73r

From the product page https://m.shenzhenaudio.com/headphone-amplifier/singxer-su-1-usb-digital-interface-with-xmos-xu208-cpld-dsd256-dop.html it seem u need to fiddle with the dip switch not sure what is the correct setting though for LKS.


----------



## penguin69

https://www.shenzhenaudio.com/l-k-s-audio-mh-da003-mk2-es9028pro-dac-usb-dsd-femto-clock-110v-to-250v.html​
  
 I may well order this after Xmas and work in parallel on my existing 003 and this 9028 upgrade. (Make up for lost time over the last 2-3 months, when I've been working away from home and not been able to tinker.)
  
 Does anyone know of initial reactions/reviews of the new ESS chip - irrespective of container DAC?


----------



## Stefday2

the last release (and official from LKS) of the MH-DA003 MK2 with the ESS9028pro will be here in few days
 the biggest news is not only ES9028pro because it will include a full discrete IV (balanced) and output stage (single ended)
  
  
 https://world.taobao.com/item/540405847037.htm?fromSite=main
  
 LKS told me the official web site should be updated this week


----------



## 0t73r

Quite the difference no more opamp rolling. Not sure if they perfected it or cutting corner?


----------



## -Felix-

-felix- said:


> Interesting! Unfortunately, the link is not working for me. But I found these links:
> http://www.shenzhenaudio.com/l-k-s-audio-mh-da003-mk2-es9028pro-dac-usb-dsd-femto-clock-110v-to-250v.html
> http://www.shenzhenaudio.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/_/-/_-14_3_1.jpg
> https://translate.google.de/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%2Fwww.hiendy.com%2F%3Fp%3D8226
> ...


 
  
 Here is the update to the official LKS website for the MKII.
 http://mu-sound.com/ProductView.Asp?id=22
 http://www.mu-sound.com/UploadFiles/20171293019273.jpg
  
 The pictures show a completely different design around the two ES9028pro chips compared to the links I posted before. I would be very interested in a good analysis of the new design.


----------



## Stefday2

it seems almost the same design except instead of opamp now you have a discrete (and class A annunciated) stage for I/V and single ended output.
  
 it could be nice only if the stages are really better than the opamp, because it's almost not possible to change or update it where it's very easy to roll the opamps. you could find as well kind of opamp based on discrete component like the Ticha994. so the choice is not easy...


----------



## b0bb

MKII looks like a mixed bag to me.
  
The Good:
 1)Use of the TI TPS7A4700RGW Low noise regulator for the XO and the 1.2V supplies
 2)Nichicon KG SuperThrough Caps for the Analog powersupply, this is the best KG grade
 3)LKS finally got rid of the Vcom trimmer, it was poorly bypassed by a leaky electrolytic, this wreaked sound quality havoc on the MKI
 4)Use  of the Nichicon R7 polymer caps in some of the supplies
 5)LKS kept the Amanero Combo384 USB interface, I find it superior to the XMOS stuff including the latest XU208
 6)Big output transistors on the discrete opamps should have no problems handling the 32mA fullscale DAC output current
 7)LKS kept the DIL-14 pads around the XO, this leaves open the option of tossing out the CCHD575 for a better XO.
  
The Bad:
 1)The XO, the CCHD575 of one of the main culprits of the harshess and thin presentation of the stock MKI. I found that the 575 looked good on paper but was the poorest sounding XO in the range I experimented on the MKI
 2)LKS appears to be still using the older LT regulators on the 3.3V lines
 3)Use of audio grade electrolytics to filter/bypass the digital supplies, I found the Nichicon R7 to be much better all around for the digital lines.
 4)LKS used thinner and narrower profile caps in the filter section compared to the MKI, this may limit the modification options like using film+foil plastic caps, these are rather bulky so may not fit, we are left with having to use poorer sounding metallized caps.
  
The maybes:
 1)The discrete parts looks like an opamp implemented in discrete logic, I would have liked it better if LKS implemented a discrete I/V converter instead of rehashing the opamp virtual earth I/V that the MKI used.
  
 2)LKS does not appear to have used any dual transistor packages, the SMT transistors that I can see on the board all have 3 output terminals, this means single transistors. Better close up shots of the discrete opamp is needed.
  
 2 transistors on the same silicon gives substantially improved thermal tracking  and 2 on-die transistors matched at the silicon foundry can be superior to doing it at assembly time.
 Examples where the transistors perform best when they are on the same die

Differential input pair
2 or 4 transistor current mirror active load for the voltage amplification stage
The 2 transistor current source use to load the input diff pair
  
 3)The 9028's output is 2 signals opposed in polarity, both sides of the signal have to be very tightly matched to give the best distortion performance, a discrete opamp can be a step backwards especially if the parts are not tightly matched.
 This means the feedback loop has to do extra work to fix the linearity problems caused by differences in mismatched transistor gain and which is highly temperature dependent.
  
 4)LKS appear to be using silvered mica caps in the I/V section, this has the effect of making the sound brighter. I found this when modding the MKI, this makes the harsh sound of the MKI even harsher, something to keep an eye on on the MKII
  
 5)LKS used Panasonic tantalum POSCaps in some places on the MKI, on the MKII they started using the cheaper Nichicon R7, looks like a cut corner to save cost.


----------



## 0t73r

I think my lks audio left and right is not in balance. I am using xlr connector is there a way to match it?


----------



## b0bb

0t73r said:


> I think my lks audio left and right is not in balance. I am using xlr connector is there a way to match it?


 

 Measure the XLR voltage output with a mono audio signal playing
 Try this 100Hz wav file http://www.mediacollege.com/audio/tone/files/100Hz_44100Hz_16bit_05sec.wav
  
 Use the AC Volts range of a multimeter and measure between XLR pins 2 and 3, both channels should measure the same  if it is working correctly.
 Also check the DC voltage between pins 1 and 2, it should be less than 6mV DC.


----------



## 0t73r

b0bb said:


> Measure the XLR voltage output with a mono audio signal playing
> Try this 100Hz wav file http://www.mediacollege.com/audio/tone/files/100Hz_44100Hz_16bit_05sec.wav
> 
> Use the AC Volts range of a multimeter and measure between XLR pins 2 and 3, both channels should measure the same  if it is working correctly.
> Also check the DC voltage between pins 1 and 2, it should be less than 6mV DC.


 

 Thanks very much b0bb,
  
 It was first apparent after changing the i/v opamps, now it settling down somewhat (after burning in 12hrs+) but the stereo image sometimes a bit more to the right when I am listening at high SPL especially the centre image.
  
 Assuming looking at the back of DAC. XLR Pin 1 3 2 where 3 is the bottom middle pin and 1 is left pin. With DAC VOL-FIXED (I have always use this as I have analog preamp), below are my readings.
  
 I have measured my voltage using stereo lossless 100hz sine wave amplitude of 0.99 created by audacity as the DAC not accepting mono files. My XLR readout for pin 2 and 3; Left = 4.6Vac Right =  4.7Vac .  While other combination readout pin 1,3 or 1,2 shown 2.2Vac for left and right.
  
 Ok so for 0.9 amplitude of 100hz, my readouts Left = 4.2Vac Right =  4.2Vac. So it seems only affected higher amplitude wave, like dynamically compressed music.  
  
 Measured during Idle and playback pin 1 and 2 is below 6mV for left and right, 2-3mV give or take.
  
 The opamp I am using now is from LKS design https://world.taobao.com/item/541577701038.htm?fromSite=main&spm=a312a.7700824.w9789869-11612113831.2.tBIJsx . There are a pot on the opamp although I did not touch any of it as I am not sure where to measure. Moreover I change back to original op amp and the readout are still the same Left = 4.6Vac Right =  4.7Vac .
  
 b0bb need your guidance on this and thanks for your time, is there any suggestion?


----------



## b0bb

0t73r said:


> Thanks very much b0bb,
> 
> It was first apparent after changing the i/v opamps, now it settling down somewhat (after burning in 12hrs+) but the stereo image sometimes a bit more to the right when I am listening at high SPL especially the centre image.
> 
> ...



 


The numbers look ok, if you put the stock opamps back and the problems go away, the source of the issues is likely the new I/V opamps.

Dynamic compression is one step before the opamp goes into clipping, so it is struggling at this point.


----------



## 0t73r

> Ok so for 0.9 amplitude of 100hz, my readouts Left = 4.2Vac Right =  4.2Vac. So it seems only affected higher amplitude wave, like dynamically compressed music.


 
 I could have written wrong value there as the left value was dancing around 4.1-4.2Vac on my digital multimeter, maybe 4.15-4.19Vac I couldn't get better decimal fraction as my multimeter only produce the tenth on the AC scale thus rounding it.
  
 b0bb it is similar voltage output using the original opamp. Reason I am detecting it now I believe the new opamp produce better separation front and back, i.e you can find the bass, drum behind and the vocal is in front of them, so they are not clashing together in the centre stereo image, thus it is more focus. I can easily pinpoint where the singer is and the instrument placement.
  
 Below is my readouts using original opamp using .99 amplitude.
               Left Vac             Right Vac
 10Khz       3.2                  3.3
 9Khz         3.4                  3.5
 8Khz         3.5                  3.6
 7Khz         3.7                  3.8
 6Khz         3.8                  3.9
 5Khz         4.0                  4.1
 4Khz         4.1                  4.2
 3Khz         4.2                  4.3
 2Khz         4.3                  4.4
 1Khz         4.4                  4.5
 800hz       4.5                  4.6
 100hz       4.6                  4.7
 60hz         4.6                  4.7
 30hz         4.6                  4.7
  
 As can be seen left channel have 0.1Vac less consistently on the frequency spectrum.
  
 Additionally if the singer have a high pitch tone (more energy on higher frequency) like women then she will be singing off centre, a bit to the right (maybe 5-10%). However if the singer have deeper voice tone then he/she will be correctly at the centre. I think higher note frequency is very directional and low note frequency not so much. Problem I am having also affect the decay, I will always heard it moving a bit to the right.
  
 For now, I will try positioning my left loudspeaker toe in more towards the centre, hopefully this will make a difference but I will be buying headphone soon for the late night listening session.
  
 So it is safe to say it is not opamp issue. Should I replace few components but I don't know where to start.
 Please help, what more can I do?


----------



## b0bb

0t73r said:


> I could have written wrong value there as the left value was dancing around 4.1-4.2Vac on my digital multimeter, maybe 4.15-4.19Vac I couldn't get better decimal fraction as my multimeter only produce the tenth on the AC scale thus rounding it.
> 
> b0bb it is similar voltage output using the original opamp. Reason I am detecting it now I believe the new opamp produce better separation front and back, i.e you can find the bass, drum behind and the vocal is in front of them, so they are not clashing together in the centre stereo image, thus it is more focus. I can easily pinpoint where the singer is and the instrument placement.
> 
> ...



 


The results you posted show an average of 2-3% difference, this is within the tolerance of the AC voltmeters in common use.

This means, statistically, output level between the left and right channels of the DAC at the measured frequency ranges are the same.

Suggest you look elsewhere for the source of the problem or try on a set of headphones. Modifying the LKS is not recommended for this problem.


----------



## penguin69

b0bb said:


> MKII looks like a mixed bag to me.
> 
> The Good:
> 1)Use of the TI TPS7A4700RGW Low noise regulator for the XO and the 1.2V supplies
> ...


 

 Thanks for the review, b0bb. Will you be looking to acquire the new Mk II to modify, or will you just stick with the Mk I ?


----------



## b0bb

penguin140369 said:


> Thanks for the review, b0bb. Will you be looking to acquire the new Mk II to modify, or will you just stick with the Mk I ?



 


I am in the wait and see mode. The 9028 is a wildcard, on the horizon is the 9038, this is the chip I have on my list.
The MKII seems like rushed job, given LKS's product history there is likely a followup to the MKII.


----------



## b0bb

The discrete opamp on the MKII is similar to the standalone opamp LKS is selling.


 Red outline above is the input differential pair, yellow outline is the DC offset trimmer, blue outline shows the single discrete transistors in use.
  

  
 Red outline shows the input pair in close proximity to the DC offset trimmer.
  
 LKS appears to be using opamps on the MKII as they did in the MKI except it is made of discrete parts.
  
 LKS's discrete opamp does not appear to make use of dual transistors except on the input pair.
  
 Both Sparkos  on the SS3602 and Sonic Imagery on the Ticha 992/994 make extensive use of thermally coupled dual transistors as highlighted below
  


 Sparkos SS3602
  

  
 Sonic Imagery Ticha 992
  
  
 Notice that neither Sparkos nor Sonic Imagery have DC trimmers on their opamps, this suggests better matching of the parts  and no trimmer means one less part to fail.
  
 The LKS part looks crudely built in comparison, I had initially thought it was a $20 USD part.
  
 Most surprising is the asking price for the LKS dual opamp
  
 Taobao $85 USD
 Ebay $140 USD, this makes LKS more expensive than the Dual Ticha 994 and about 2X the price of the Sparkos.
  
 Not a lot of info on the part.
 It operates in ClassA up to 40mA of load current so it should be able to handle the 9028/9018's full output current (32mA)


----------



## penguin69

LKS discrete opamp looks a bit like the Dexa NewClassD op amp I used in my Eastern Electric DAC's. That also had a built in trimmer.


----------



## penguin69

Vishay resistors (texascomponents) and a few other bits and pieces (mouser) just ordered. After a work-enforced hiatus of quite a few weeks, I am now in a position to start round two of mods on my MH-DA003.


----------



## 0t73r

Cool keep us posted. I am thingking of modding this DAC.


----------



## b0bb

penguin140369 said:


> LKS discrete opamp looks a bit like the Dexa NewClassD op amp I used in my Eastern Electric DAC's. That also had a built in trimmer.


 

 It does, the dual DEXA is about $40 USD
  
 http://www.partsconnexion.com/opamp_dexa.html


----------



## b0bb

penguin140369 said:


> Vishay resistors (texascomponents) and a few other bits and pieces (mouser) just ordered. After a work-enforced hiatus of quite a few weeks, I am now in a position to start round two of mods on my MH-DA003.


 
  
 Nice.
 Suggest you add one set of mods at a time starting with the I/V resistors followed by the Schottky diodes, these have the longest settling time, typically 4-7 days burn in.


----------



## penguin69

Yes, for sure. I'm still on a steep learning curve so I'll be doing things procedurally and very slowly.


----------



## b0bb

Latest addition, this is the NewClassD DEXA Special Edition
 http://www.newclassd.com/index.php?page=123&hv=1
  
 This is a high bias (20mA) Class A opamp

  
 This has replaced the Burson V5, I was using previously in the balanced to single-ended converter
  
 The soundstage got considerably wider and the transients (snare drum, kickdrum, hihat, bells, triangles)  were clearer.
  
 Bass output extended down by almost 1/2 octave, the double bass rendition was deep and tight, electric bass guitar sounds very much like a very big stringed instrument compared to the indistinct blubbery sound that was the previous norm.
  
 With the DEXA the difference between the unbalanced and balanced outputs was non existent.
  
 In terms of the opamps I have used in this role, the pecking order in terms of decreasing performance
  
 Dexa SE, Burson V5, Sparkos SS3602, NJR Muses 01, Stock Opamp.
  
 The DEXA was about the equivalent of the Ticha 994 in this role.
  
 Further closeup

  
 The 3 LEDs are quite pretty, picture without flash.

  
  
 The last 2 pictures show the DEXA in the I/V role.
  
 Performance was mediocre at best, despite the high Class A like bias.
  
 Compared to the Ticha 994 the soundstage underwent a dramatic collapse with a great loss in transparency and the absence of the fast transients.
  
 The flip side was a much warmer presentation with emphasis on the midrange, particularly in the vocal ranges.
  
 Does not look like the DEXA can replace the Ticha 994.


----------



## b0bb

0t73r said:


> So it is safe to say it is not opamp issue. Should I replace few components but I don't know where to start.
> Please help, what more can I do?


 
  
 The opamp is not suitable for the LKS despite the fact it comes from the same manufacturer.
  
 Initially I had not realized the extreme cost of the LKS offering, if you want to save the purchase take a look at the recommendation below, it requires patience and persistence and the results are not guaranteed, but a case of 2 steps forward and one back.
  
Background explanation
 The ES9018 is very sensitive to output loading in current output mode, the output is a series of fast current pulses up to 32mA coming out of the chip in the frequency range of 1-30MHz, the opamp has to track these changes and the resulting difference in the steps is the actual audio output.
  
 Any mismatch in the output impedance of the DAC and the input impedance of the I/V converter can cause some of the current to be reflected back into the DAC, this distorts the output considerably.
 LKS added a matching network to even out the difference.
  
 The existing LKS design used bipolar input opamps and the input capacitance is about 6pF, the Ticha 994 which I used the capacitance is between 3-5pF.
 The LKS opamp you used has JFET input, this type of transistor has much higher input capacitance typically between 30-50pF.
  
 This existing matching network is on the motherboard needs to be altered to correct the the mismatch
  
 This partially explains the high frequency artifacts you are hearing.
  
  
Potential fix

  
 The highlighted squares are part of the compensation network mentioned above, the default value is 220pF.
  
 Start by decreasing the value in 5pF steps.
  
 Specific issues
 1)Caps in the same colored rectangles must be matched to better than 1%, the audio signal is the difference in the output between the 2 halves of the I/V converter, so the distortion (THD) can be up to 1% with the specified tolerance.
  
 2)Ideally a fast scope of 300MHz or more should be used to see the pulse shape coming out of the DAC, these are quite costly, you may have to resort to trial and error and listen carefully between each change.
  
 3)Once you do this, you be stuck with using JFET input opamps unless you undo the change.
  
 4)There will be a point where the cap value becomes too low and the opamp will start to oscillate, it will get hot quickly and the high frequency sound will start to sound brittle, stop the work as this will contain enough high frequency noise to damage the tweeters of your speakers.
  
 Your best bet for precision caps is silvered mica caps as they are available in 1% tolerance, not as good as the polyproplylene film foil caps that comes with the DAC


----------



## 0t73r

Thank you very much b0bb for the comment. For the moment I have to find a good listening position adjusting my head to get the good spot. It is fix somewhat for me, vocal is at centre now. I will try to look in to this mod, need to invest some knowlege and test equipment first.

During first listening of the opamp I thought the gain is a bit high, I dont know how to explain, I play guitar so the sound is like when you increase the gain on a guitar amp. But now, the gainy sound is lost maybe my ears get used to it or maybe after burned in.

So far I am pretty happy with the sound signature, I can listen to music at very long session. Sibilance somewhat reduce, that might be also because I mod my speaker by adjusting the wadding. I love how jazz brush drum sound with this dac, sounded well define at high frequency. All together I think the music sound sweet to me .

Although I have not tried this with headphone yet.


----------



## Tomus4

b0bb said:


> 0t73r said:
> 
> 
> > Thanks very much b0bb,
> ...


 
 I had two times opamp Burson V5 failure which I have in the RCA outputs.   Opamps was damaged only in the left channel.
  
 I checked supply voltage and it is ok - 29,7V in both channels.
 But in the RCA output is 1,5mV DC in the left channel. In the right channel is 0mV
  
 I changed opamps to original one 1612 and output voltage is almost the same 1,4mV in the left channel and 0mV in the right. I changed opamps places (right to left and left to right) and still in the left channel voltage is about 1,5mV.
  
 In the XLR outputs voltage is:
 - Right channel. 
               0,1mV between pins 1 and 3 
               0,1mV between pins 2 and 3 
 - Left channel
                0,1mV between pins 1 and 3 
               4,1mV between pins 2 and 3 

 I set up voltage blue trimpot and value above are minimal what is possibile to set up. When I try to set around 0mV between pins 2 and 3 (Left channel) voltage between pins 1 and 3 rise to 90mV
  
 Do you have any idea what to do? And if higher DC voltage is cause damage Burson opamps in the left channel?
 Should I set 4,6mV between pins 2 and 3?
 How I can reduced dc voltage to 0mV in the left channel RCA output?


----------



## penguin69

b0bb said:


> Latest addition, this is the NewClassD DEXA Special Edition
> http://www.newclassd.com/index.php?page=123&hv=1
> 
> The 3 LEDs are quite pretty, picture without flash.


 
  
 Yes, the lights are nice.
  
 I'm running just with the Ticha's currently so don't have that nice night-time glow from my (slightly older version) Dexa's anymore. 
  
 Schottky rectifier diodes now installed on the digital side of my unit:
  


 Unit being tested as I write, all seems well. I won't fully judge the SQ until the modifications have bedded/burned in. Things do seem a little sweeter and the 'attack' of notes quicker if anything with the new diodes, but that could be my imagination or expectation bias.
  
 It was a struggle to remove the original diodes. Even after clearing the solder, the diodes remained beligerently in place and could not be shifted either with tweezers or through leverage using a small screwdriver. I eventually cleared them by breaking them away, which was sub-optimal to say the least and made the task of soldering in the new diodes harder than it should otherwise have been.
  
 Time is tight these days so it may be a couple of weeks or so before I can add some of the other mouser or texas components that have recently arrived. Will post again when I have done something new.


----------



## Tomus4

-felix- said:


>


 
 Hi b0bb,
 I'am looking for Corning low-K CGW Glass Cap for around I/V opa change. I've found https://www.surplussales.com/capacitors/RF-Vitramon.html page.
 They have only 100pF Corning but a lot of Vitramon Glass Capacitors. What do you think about:
 (CFM) VY13C201F    200 pF    500v    Radial Gold    1%    
 (CFM) VY82C241F    240 pF    2kv    Axial    1%    
 (CFM) CY12C301F    300 pF    300v DC    Radial Corning    1%


----------



## b0bb

tomus4 said:


> I had two times opamp Burson V5 failure which I have in the RCA outputs.   Opamps was damaged only in the left channel.
> 
> I checked supply voltage and it is ok - 29,7V in both channels.
> But in the RCA output is 1,5mV DC in the left channel. In the right channel is 0mV
> ...


 
  
 The DC supply voltage is below 30V, this within acceptable limits for the Burson, contact them about the failures to get replacements.
  
 The blue trimpot on the left channel may be faulty, given the sudden jump in output you are seeing, however 1.5mV is not going to cause any DC problems down stream.
 I do not expect that you will be able to reduce the offset any further on the left channel without component replacement.


----------



## b0bb

tomus4 said:


> Hi b0bb,
> I'am looking for Corning low-K CGW Glass Cap for around I/V opa change. I've found https://www.surplussales.com/capacitors/RF-Vitramon.html page.
> They have only 100pF Corning but a lot of Vitramon Glass Capacitors. What do you think about:
> (CFM) VY13C201F    200 pF    500v    Radial Gold    1%
> ...


 
  
 The Vitramon caps will worsen the sound, I bought a few from Surplus Sales to try.


----------



## b0bb

penguin140369 said:


> Schottky rectifier diodes now installed on the digital side of my unit:
> 
> 
> 
> ...


 
  
 The process can be made easier if the diodes and the board are pre-heated with hot air, this halves the removal time. Large metal bits in the stock diodes absorb a lot of heat.
  
 This makes desoldering difficult if preheating is not done.
  
 The net result of this mod is a much sweeter presentation and as you note it does make an improvement to the transient attack.


----------



## penguin69

Thanks b0bb.
  
 The hot air gun on my solder station decided not to work this weekend, otherwise I would have taken that approach. Any recommendations for a good quality replacement unit?


----------



## b0bb

This is what I use, but I replaced all of the crappy caps in there with 105C 10Khour caps from Nichicon and Chemicon, otherwise quality parts, uses a genuine Samsung PID controller.
  
 Very versatile device that can desolder large jobs down to fine things like soldering SMD XOs and doing heat shink and reworking hot melt glue jobs.

  
 http://yihua-soldering.com/product-3-3-4-hot-air-rework-station.html/158746


----------



## Tomus4

b0bb said:


> The Vitramon caps will worsen the sound, I bought a few from Surplus Sales to try.


 
 So Silvered Mica you mentioned above response to -Felix- is better than Vitramon? Or maybe is better to stay with WIMA?


----------



## Tomus4

b0bb said:


> The DC supply voltage is below 30V, this within acceptable limits for the Burson, contact them about the failures to get replacements.
> 
> The blue trimpot on the left channel may be faulty, given the sudden jump in output you are seeing, however 1.5mV is not going to cause any DC problems down stream.
> I do not expect that you will be able to reduce the offset any further on the left channel without component replacement.


 
 So replacement blue trimpot should solve the problem? That's OK because I plan to do this and insert Vishay 10K foil trimmer.
 Thank you very much.


----------



## Tomus4

tomus4 said:


> So replacement blue trimpot should solve the problem? That's OK because I plan to do this and insert Vishay 10K foil trimmer.
> Thank you very much.


 
 trimpot of course


----------



## Mareli

b0bb I see now you use the Pulsar clock. Compared with Crystek CCHD-950 is there a significant improvement in sound quality to justify the difference in price? Is it worthed ?
 Thanks


----------



## b0bb

tomus4 said:


> So Silvered Mica you mentioned above response to -Felix- is better than Vitramon? Or maybe is better to stay with WIMA?


 

 Stay with the Wima caps for bypass if you cannot find the CGWs, they appear every now and then on Ebay.


----------



## b0bb

tomus4 said:


> So replacement blue trimpot should solve the problem? That's OK because I plan to do this and insert Vishay 10K foil trimmer.
> Thank you very much.


 

 That is the most obvious culprit, they may be secondary causes but this should be eliminated first


----------



## b0bb

mareli said:


> b0bb I see now you use the Pulsar clock. Compared with Crystek CCHD-950 is there a significant improvement in sound quality to justify the difference in price? Is it worthed ?
> Thanks


 

 Yes.
  
 This should only be done after all the other mods are completed, with said mods and the 950X (not the 950) the DAC is about the same performance as the Schiit Yggdrasil R2R DAC.
 I keep this DAC in stock form as a reference.
  
 With the Pulsar, the LKS is taken to another level in terms of imaging and positioning and increased resolution, I started to hear details from tracks I have had for a long time, without compromising any other areas.
  
 I find my expenditure justified for the benefits it added to my dac.


----------



## Mareli

I currently have the Singxer F-1 USB module in my LKS dac. And I like it much better then the original amanero board.
 Do you think the upgraded LKS amanero board you are using is better?


----------



## b0bb

I bought the F-1 specifically to see if could replace the upgraded Amanero, it could not.
  
 The F-1  improved the clarity of the presentation compared to the stock Amanero but emphasized the less desirable characteristics of this DAC namely sibilance and thinning of the vocal ranges.
 The upgraded Amanero brought the clarity without the above mentioned compromises.


----------



## Mareli

Thanks for your input. I will upgrade my DAC with the mods you did but for the output stage I recommend to use 2 Lundahl LL1684 transformers. I tried different Opamps including the ultra low distortion low noise fully differential OPA1632, but with transformers the sound is just sweet. I removed completely the original output stage, no I/V resistors no capacitors no Op amps to worry about just pure high quality transformers. They are expensive thou. And the best part is I could remove the input capacitor from the front end of my amplifier and now there is no crappy capacitor in the audio signal path whch I found them very harmfull.
 More info can be found here http://www.audiodesignguide.com/DAC32/index2.html


----------



## Mareli

F-1 has the CCHD-575 crystals and your Amanero board has CCHD-957 which much better.
 So comparing both of them is not quite fair. A a better match will be the SU-1 which has CCHD-957.
 Have you tried SU-1?


----------



## b0bb

mareli said:


> F-1 has the CCHD-575 crystals and your Amanero board has CCHD-957 which much better.
> So comparing both of them is not quite fair.


 
  
 I think the above answers your original question


> Originally Posted by *Mareli* /img/forum/go_quote.gif
> 
> 
> Do you think the upgraded LKS amanero board you are using is better?


----------



## penguin69

Was planning to starting today on modifying the USB board in my MH-DA003, having bought some new caps for it, only to realize that the parts I bought are for the uprated board - and I have the old one. Duh.
  
 Will look back through the thread to see where I can get it ordered from.
  
 On a separate note, my Texas Components order still hasn't arrived (bits for the output stage), I'm starting to think it has got lost.


----------



## Tomus4

I have found *Corning Glass Capacitors: ​*(CFM) CY06C101F    100 pF    300v DC    Radial, gold leads    1%  on the http://www.surplussales.com/Capacitors/RF-Vitramon.html
 If I parallel it to achive 200pf will be ok?
  
 This Corning are CY yours TY. Is it a big difference?


----------



## b0bb

tomus4 said:


> I have found *Corning Glass Capacitors: ​*(CFM) CY06C101F    100 pF    300v DC    Radial, gold leads    1%  on the http://www.surplussales.com/Capacitors/RF-Vitramon.html
> If I parallel it to achive 200pf will be ok?
> 
> This Corning are CY yours TY. Is it a big difference?


 
 CY06C101F looks OK.
  
 I have used both the CY and TY type caps, the only difference appears to be different US Govt procurement reference numbers.


----------



## b0bb

penguin140369 said:


> Was planning to starting today on modifying the USB board in my MH-DA003, having bought some new caps for it, only to realize that the parts I bought are for the uprated board - and I have the old one. Duh.
> 
> Will look back through the thread to see where I can get it ordered from.
> 
> On a separate note, my Texas Components order still hasn't arrived (bits for the output stage), I'm starting to think it has got lost.


 

 Followup with Texas Components to see if it has shipped, it takes them 10-14 working days to make the resistors.


----------



## Tomus4

b0bb said:


> CY06C101F looks OK.
> 
> I have used both the CY and TY type caps, the only difference appears to be different US Govt procurement reference numbers.


 
 So it is nessesary to buy all togever 8 x 200pF caps - 2 for each opa, isn't it?
 Has it  to be parallel with 150nF MKP2 WIMA or can I leave factory 100nF WIMA? Why you change 100nF to 150nF?


----------



## b0bb

tomus4 said:


> So it is nessesary to buy all togever 8 x 200pF caps - 2 for each opa, isn't it?
> Has it  to be parallel with 150nF MKP2 WIMA or can I leave factory 100nF WIMA? Why you change 100nF to 150nF?


 

 Yes all 8 positions need the bypass caps.
  
 The original 100nF caps were MKS or MKS2, this is mylar film, I changed to MKP2 which is polypropylene film, 150nF is the nearest value I had available.
  
 I measured a lower loss factor on the MKP2 at high (>100kHz) frequencies which is useful for bypass applications, it also sounded a lot better with the MKP2 in place.


----------



## Tomus4

b0bb said:


> Yes all 8 positions need the bypass caps.
> 
> The original 100nF caps were MKS or MKS2, this is mylar film, I changed to MKP2 which is polypropylene film, 150nF is the nearest value I had available.
> 
> I measured a lower loss factor on the MKP2 at high (>100kHz) frequencies which is useful for bypass applications, it also sounded a lot better with the MKP2 in place.


 
 Thank you for replay
 And last questions about caps around the opa is about what you change to polystyrene cap.
 What is the capacity in yours LKS? Or what capacity will be suitable?
 What do you think about removing this one are parallel to TX2575? In the new model manufacturer done this.


----------



## penguin69

b0bb said:


> Followup with Texas Components to see if it has shipped, it takes them 10-14 working days to make the resistors.


 

 Yes, I did over the weekend. Looks like the order is lost, as it was dispatched by Texas Components back in January, just waiting to hear back for sure. 
  
 In the UK, if an order is lost then the supplier will resend - not sure how it works when goods are shipped from the USA to UK. I hope I don't end up out of pocket.


----------



## b0bb

tomus4 said:


> Thank you for replay
> And last questions about caps around the opa is about what you change to polystyrene cap.
> What is the capacity in yours LKS? Or what capacity will be suitable?
> What do you think about removing this one are parallel to TX2575? In the new model manufacturer done this.


 

  
  
 These caps should be left alone, this is used to match the 9018 output impedance to the I/V input impedance and is specific to this DAC model, the newer model has a different DAC chip, the 9028 and different opamp
  
 Polystyrene caps in this position removes the hard high frequency edge from the 9018's sonic signature, same value as stock 220pF.
  
 Post #426 is an example of what can happen if impedance is mismatched.
 http://www.head-fi.org/t/745032/lks-audio-mh-da003/420#post_13146429


----------



## b0bb

penguin140369 said:


> Yes, I did over the weekend. Looks like the order is lost, as it was dispatched by Texas Components back in January, just waiting to hear back for sure.
> 
> In the UK, if an order is lost then the supplier will resend - not sure how it works when goods are shipped from the USA to UK. I hope I don't end up out of pocket.


 
  
 Hope things work out.


----------



## Tomus4

b0bb said:


> Yes.
> 
> This should only be done after all the other mods are completed, with said mods and the 950X (not the 950) the DAC is about the same performance as the Schiit Yggdrasil R2R DAC.
> I keep this DAC in stock form as a reference.
> ...


 
 I have colleted almost all stuff for doing mod you describe in this thread. Now I'm thinking about clock - buy 950X or make all change around and on the end buy the Pulsar even I have to wait 1..2 months to find money for it. If I understand well better will be wait. - not to buy 950X = have 10% money for Pulsar


----------



## Jerry-S

Hi everyone, first post. Very interesting conversation and super informative. 
  
 Question:
 1. Am I correct in assuming this unit can be used as a pre-amp since it has a Volume control?
 2. If so, is anyone currently using it for this role in their system and how would you rate it?
 3. Would it be better to buy a dedicated Pre-amp instead of using this?
  
 Thanks


----------



## b0bb

jerry-s said:


> Hi everyone, first post. Very interesting conversation and super informative.
> 
> Question:
> 1. Am I correct in assuming this unit can be used as a pre-amp since it has a Volume control?
> ...


 
  
 1. Only for digital sources, the variable volume output sounds worse than fixed volume, it messes up the sound stage and imaging.
 3. An external preamp is recommended if sound quality is more important.


----------



## Jerry-S

By fixed volume you mean volume pot at Max? or is this an internal setting?


----------



## b0bb

jerry-s said:


> By fixed volume you mean volume pot at Max? or is this an internal setting?


 
 Fixed  volume is  special mode accessible from the remote control


----------



## Tomus4

Hi b0bb,
  
 What do you thing about voltage regulators:
 - http://www.newclassd.com/index.php?page=130&hv=1
 - http://sparkoslabs.com/discrete-voltage-regulators/ 
 compare to http://tekdevice.com/chapter2/index.php?route=product/product&path=25&product_id=87


----------



## fjc36

Dear bobb,
  
 " the 950X (not the 950),"
  what is the difference btw them? spec.? or performance?  
 I am confused, can't tell the difference of them in the spec.  
 thanks


----------



## Lambertyip

Hi Bobb,
  
 I have followed this thread for a long time. I modded my DA003 by replacing the Opamp and crystal. I am going to do the 2nd mod by replacing the resistors and capacitors. 
  
 You mentioned to replace the  8x100nF MKS capacitors around the Opamp by 150nF MKP2 with Corning glass capacitors bypass. I have a question about the values of the glass capacitors that needs your confirmation.
  
 1. You mentioned to use  220pF CGW for the bypass in  IV conversion, i.e. around Ticha994.  I could not find the smaller CY06 and I bought CY15C221J from ebay. It is  a bit bigger and axial. Is it fine to use still? http://www.ebay.com/itm/322056185369   Total 4 pieces.
  
 2. Regarding the balance to unbalance conversion, i.e. around the Burson V5 near RCA sockets, is it correct to use  M23269J 120pF glass capacitor that  you mentioned in post #381.  Or shall I keep using 220pF CGW CY15?  Total 4 pieces.
  
 I have got other components already and I shall do the 2nd mod soon. Please help. Thanks.
  
 -lambertyip


----------



## b0bb

fjc36 said:


> Dear bobb,
> 
> " the 950X (not the 950),"
> what is the difference btw them? spec.? or performance?
> ...




950X has a wider temp operating range. This is one way to get a better quality crystal.

I have both the 950 and 950X and the 950X sounds superior.


----------



## b0bb

tomus4 said:


> Hi b0bb,
> 
> What do you thing about voltage regulators:
> - http://www.newclassd.com/index.php?page=130&hv=1
> ...




The tekdevice board contains the TI TPS7A47 regulator, this is a very low noise regulator designed for high speed digital circuits, the other two are conventional regulators, best used for the analog parts of the DAC, when used on the digital side, I do not expect them to perform any better than the stock LT317.

There is no need for the other two as the LKS already has a very good discrete regulator for the analog side.

The Belleson SPL regulator is similar to the other two regulators and I use these type of regulators in the analog side of the DAC.
The same tekdevice regulator is used for the digital part of the DAC below.
Below is an example on another DAC.


----------



## b0bb

lambertyip said:


> 1. You mentioned to use  220pF CGW for the bypass in  IV conversion, i.e. around Ticha994.  I could not find the smaller CY06 and I bought CY15C221J from ebay. It is  a bit bigger and axial. Is it fine to use still? http://www.ebay.com/itm/322056185369   Total 4 pieces.
> 
> 2. Regarding the balance to unbalance conversion, i.e. around the Burson V5 near RCA sockets, is it correct to use  M23269J 120pF glass capacitor that  you mentioned in post #381.  Or shall I keep using 220pF CGW CY15?  Total 4 pieces.
> 
> ...


 
  
 1. Those are fine, try to keep the lead as short as possible.
  
 2. Either one will work


----------



## Tomus4

b0bb said:


> 1. Those are fine, try to keep the lead as short as possible.
> 
> 2. Either one will work


 
 If I understand 
 1) for bypass supply of I/V is needed 200pF or more
 2) for bypass supply of unbalance conversion is needed 100pF or more
 I have 100pF CGW so I want be sure if I should parallel it in only 1) circuit or both


----------



## Tomus4

b0bb said:


> The tekdevice board contains the TI TPS7A47 regulator, this is a very low noise regulator designed for high speed digital circuits, the other two are conventional regulators, best used for the analog parts of the DAC, when used on the digital side, I do not expect them to perform any better than the stock LT317.
> 
> There is no need for the other two as the LKS already has a very good discrete regulator for the analog side.
> 
> ...


 
 Understand. So there is sense to replace only those 3 regulators:

 to TI TPS7A4700 5V regulator from TekDevice


----------



## HolyDiver

Quote:


b0bb said:


> Spoiler: click to show
> 
> 
> 
> ...


 
  
 I did my research and found out that there are 3 versions of LKS DACs - MH-DA003 (original model with ES9018), MH-DA003 MK2 (intermediate model with ES9028Pro), both with rolling op amps and MH-DA003 MK2 (final model with ES9028Pro) with discrete op amps. Based on the pictures I found online (please, correct me if I'm wrong) the original LKS has OPA1612A op amps and intermediate model has boards with dual L49990MA on them. Does anybody have an experience or information on MH-DA003 MK2 intermediate and final models with ES9028Pro?
 I'm trying to understand the difference between those two and whether one is better than another? Also, would be safe to assume that both of them might be exchanged for 994Enh-Ticha Dual in I/V circuit and would there be an improvement in the sound if 994Enh-Ticha Dual is used in both cases? Thank you.


----------



## b0bb

tomus4 said:


> Understand. So there is sense to replace only those 3 regulators:
> 
> to TI TPS7A4700 5V regulator from TekDevice


 
  
 A couple of comments
 1)The left one goes to the DAC, the other two are optional.
  
 2)The heatsinks have to be removed to properly mount the new regulator and to check for short circuits.
  
 3)Get the LM317 version not the 78XX version. The LM317 version did not exist when I did my mod, so there is no need to add the wires like I did
 http://tekdevice.com/chapter2/index.php?route=product/product&path=25_54&product_id=142
  
 4)The voltage adjustment resistors and bypass cap have to be removed from the motherboard. Bypass cap terminals shorted

  
  
 5)The Tekdevice board needs a 10uF tantalum capacitor soldered between  the IN pin on the regulator and ground, a suitable point is the bypass cap location, the one with the soldered jumper.
 I mounted the the 10uF cap on the other side of the board.
  
*NOTE: +ve electrode to the IN terminal and -ve to ground, do not connect the tantalum cap in reverse*
  
 Here is a suitable cap
 http://www.mouser.com/ProductDetail/AVX/TAP106K020SCS/?qs=sGAEpiMZZMtZ1n0r9vR22d%252b8XmbM9QM8iVuE3tFomWE%3d
  
 6)Add heat sink paste between the regulator and the heatsink. Do not use the stuff  containing metal, like like Arctic silver.
 I use Dow 340
 http://www.ebay.com/itm/DOW-CORNING-340-DC340-Silicone-Heat-Sink-Compound-350-F-/280620305862
  
 7)The layout of the current Tekdevice boards are different, the mounting hole is further up, you may need to drill a new hole in the heat sink

  
 8)This is a newer design that might be better from a mounting consideration but there is additional work to be done

 http://www.ebay.com/itm/TPS7A4700-Ultralow-noise-4-VRMS-low-dropout-linear-regulators-3-5PIN-1-4V-20-5V-/252348749037?hash=item3ac12854ed:g:rRMAAOSwJkJWjBAt


----------



## b0bb

tomus4 said:


> If I understand
> 1) for bypass supply of I/V is needed 200pF or more
> 2) for bypass supply of unbalance conversion is needed 100pF or more
> I have 100pF CGW so I want be sure if I should parallel it in only 1) circuit or both


 
  
 Use the 220pf/200pF values where possible, the 100pF values are a compromise as the CGW caps are not commonly available.


----------



## HolyDiver

Reply on Posts # 441-442 (My post wasn't posted due to my "new" status and pictures in the post.)
  
 I did my research and found out that there are 3 versions of LKS DACs - MH-DA003 (original model with ES9018), MH-DA003 MK2 (intermediate model with ES9028Pro), both with rolling op amps and MH-DA003 MK2 (final model with ES9028Pro) with discrete op amps. Based on the pictures I found online (please, correct me if I'm wrong) the original LKS has OPA1612A op amps and intermediate model has boards with dual L49990MA on them.
 Does anybody have an experience or information on MH-DA003 MK2 intermediate and final models with ES9028Pro?
 I'm trying to understand the difference between those two and whether one is better than another? Also, would be safe to assume that both of them might be exchanged for 994Enh-Ticha Dual in I/V circuit and would there be an improvement in the sound if 994Enh-Ticha Dual is used in both cases?
 Thank you.


----------



## HolyDiver

Reply on Posts # 441-442 (My previous post wasn't posted due to my "new" status and pictures or outside links in it.)
  
 I did my research and found out that there are 3 versions of LKS - MH-DA003 (original model with ES9018), MH-DA003 MK2 (intermediate model with ES9028Pro), both with rolling op amps and MH-DA003 MK2 (final model with ES9028Pro) with discrete op amps. Based on the pictures I found online (please, correct me if I'm wrong) the original LKS has OPA1612A op amps and intermediate model has boards with dual L49990MA on them.
 Does anybody have an experience or information on MH-DA003 MK2 intermediate and final models with ES9028Pro?
 I'm trying to understand the differences between those two (besides having rolling and discrete op amps) and whether one is better than another? Also, would be safe to assume that both of them, OPA1612A in original model with ES9018 and dual L49990MA in intermediate model with ES9028Pro, might be exchanged for 994Enh-Ticha Dual in I/V circuit and would there be an improvement in the sound if 994Enh-Ticha Dual is used in both cases?
 Thank you.


----------



## Tomus4

b0bb said:


> Use the 220pf/200pF values where possible, the 100pF values are a compromise as the CGW caps are not commonly available.


 
 Do you think parallel connection two 100pF CGW to achive 200pF is good solution or better will be solder in only one 100pF cap?


----------



## Tomus4

b0bb said:


> A couple of comments
> 1)The left one goes to the DAC, the other two are optional.
> 
> 2)The heatsinks have to be removed to properly mount the new regulator and to check for short circuits.
> ...


 
 Thank you very much for so detailed answer
  
 I have another question. Let me know if I'm wrong, but here are LT1763 regulators:

 This part is powered via regulator what you suggest to replace. Correct?
 Is it any sens to change regulator to 4uV noise before regulators LT1763 which has 20uV noise . Maybe it also should be changed?


----------



## b0bb

tomus4 said:


> Thank you very much for so detailed answer
> 
> I have another question. Let me know if I'm wrong, but here are LT1763 regulators:
> 
> ...


 
  
 Leave the LT1763 alone, the low noise specs are only guaranteed if the layout , especially the ground plane is done to the manufacturer's specs, there is not enough space on the board to put in another  chip without compromising this requirement.
  
 Layout, not datasheet specs determines final performance, please keep this in mind when reading the datasheets.
  
 A hacked in regulator is about the worst thing you can do to the DAC, it compromises the noise performance. In the example below the 3/4 inch piece of the lead on the transistor is enough to act as a radio antenna, this injects noise into the regulator. In an area with good FM/AM radio reception this is 300uV or more (This is how simple germanium diode AM radio receivers can function).
  
 More importantly it adds unwanted distance between the regulator and the load, this degrades the load transient recovery performance of the regulator.
 Transient recovery is the ability of the regulator to quickly recover to the set voltage in the presence of a sudden increase or decrease in load current, which happens when digital logic changes state.


----------



## Mareli

I got 3x LM317 version of the regulators but I need to configure them for 3.3v and 5V. Could you please point which of the 3 regulators from the motherboard are 3.3V and which are 5V?
 It's hard to measure because of the big caps in front of the existing regulators.
 Thanks.


----------



## Tomus4

b0bb said:


> Leave the LT1763 alone, the low noise specs are only guaranteed if the layout , especially the ground plane is done to the manufacturer's specs, there is not enough space on the board to put in another  chip without compromising this requirement.
> 
> Layout, not datasheet specs determines final performance, please keep this in mind when reading the datasheets.
> 
> ...


 
 What do you thing about creating supply for clock and D/A converters based on this http://www.ti.com/lit/ds/symlink/tps7a87.pdf?  I'm thinking about removing all LT1763 and stuff around and creating small supply boards which will be connected just before clock and converters.


----------



## fjc36

Bobb thinks it is bad to have long legs of the regulator for good reason. In most of the electronic circuits, the regulators, filter diodes, specially  power transistors are stand tall on the board. Should they be shortened to avoid antenna? I do not think it is possible for shortening all of them, specially for the power transistorsl. What is a solution? shielding?  Or, in low freq. domain, analogy circuitry, it doesn't count.
  
 How was the sonic effect of the LKS MH-DA003 mk II (use CSS 9028pro chip) ? One of the reader has purchased it, Please let us know.
  
 One thing new, LKS might have the Dual 9038pro  debut before the end of 2017. I am very curious about it. Certainly, some of the implement  of 9038pro DAC already comes out, i.e. OPPO and others, but I believe they are not dual.


----------



## b0bb

fjc36 said:


> Bobb thinks it is bad to have long legs of the regulator for good reason. In most of the electronic circuits, the regulators, filter diodes, specially  power transistors are stand tall on the board. Should they be shortened to avoid antenna? I do not think it is possible for shortening all of them, specially for the power transistorsl. What is a solution? shielding?  Or, in low freq. domain, analogy circuitry, it doesn't count.


 
  
 LKS has solved all of these issues, so when you mod the DAC please be careful not to destroy the work they have already done.
  
 The LT1763 regulators connected to the DAC with very large copper areas for the ground, this is the ground plane and this is the shield you mention above. (The area is 20-50x the size of the protected area)
  
 This stops the majority of the RF/Radio pickup and suppresses the noise from ground return current coming from the 9018 chip itself.
 Unfortunately to get to the low noise numbers (20uV) the ground plane is customized for the specific layout and chip, this makes the changing out the regulators very complicated and you mentioned some of them (stand tall etc).
  
 An external board mounted 90 degrees to the ground plane reduces its shielding effectiveness to zero.
  
 Power transistors are not needed on the digital side as the max current is 300mA per rail, the LT1763 supplies up to 500mA, the eliminates power transistors from consideration.
  
 You are correct about the analog regulators, the considerations discussed here do not apply.
  
 One large ground continuous plane provides a very low impedance path back to the power supply at high/RF (>1MHz) frequencies.
  
 This is very important for the LKS as they connected both the digital and analog 3.3V supplies together and supplied this from one regulator.
  
 This works as long as the ground plane sinks/absorbs this current and prevent the noisy ground return current on the digital side from going into the analog side.
  
 When you replace the LT1763 with an external board, the ground plane is no longer continuous but 2 ground planes, original on DAC motherboard and new ground plane on regulator  connected by wire.
  
 RF noise current can flow back and forth between these 2 grounds much like an audio hum loop resulting from multiple grounds, in the RF case much worse as it has alternate paths like coupling thru the air.
  
 This is quite nasty.
  
 The noisy digital ground return current will also start getting into the analog side of the DAC affecting the sonic performance.


----------



## abartels

As always, great and useful explanation b0bb!


----------



## penguin69

Well,
  
 Good news and bad news from my latest round of upgrading.
  
 The good news is that my replacement Vishay metal foil resistors arrived today from Texas Components. (The first batch had got lost.)
  
 Also, I was able to get my rework station working again, meaning a cleaner removal of parts today.
  
 The new 0.005% tolerance resistors are installed. See pic below.
  


 On restoring the circuit board, I found that the MH-DA003 unit would not play music.
  
 I noticed that the Vdd wire to the Crystek 950 had come away, so I resoldered that, thinking that this would solve the issue. But it did not.
  
 My first thought was to revisit my resistor handiwork, perhaps by restoring one or two of the old resistors. However, before trying this I would like to hear a view on the following items that make me suspect that something may not quite be right now with the Amanero board.

 a) My Mac Mini is the transport for the DAC, running Audirvana+. When I start A+ up, the Mac OS now _deselects_ the Amanero 384 interface for output and selects Internal Speakers instead. I have never seen this behaviour before. (FWIW, the MH-DA003 now permanently shows 44K on the display with USB selected.)
  
 b) My optical input seems to remain in UNLOCK mode. I have not thoroughly tested it, I just tried a source which previously has worked.
  
 As an aside, all the usual motherboard lights come on when the unit is powered up 
  
  
 So the questions I have are as follows:
  
 1) Do the symptoms described indeed suggest a problem with the USB interface. The Mac Mini recognises the interface for what is (Amanero 384) so it can't all be bad.
  
 2) If this is a USB interface problem, what are the best diagnostic to run?
  
 3) If this is not a USB interface problem, where should I start?
  
  
 Thanks in advance for any help provided. (And thanks again to b0bb for the sage advice to only make one mod at a time. I was going to do more today, but I am glad that I did not as it would have made my problems harder to decode.)


----------



## b0bb

penguin140369 said:


> Well,
> 
> Good news and bad news from my latest round of upgrading.
> 
> ...


 
  
 Check to see the soldering on the XO is still good, did you use a socket for the XO ?
 Post close up photos of the XO, adapter etc to show the condition of the XO.
  
 The blue LEDs closest to the DAC *turn off* when there is signal lock.
  
 The original I/V resistors on the other side of the board have to be removed before adding the Vishays.
  
 Measure the voltage output of the primary regulators for the digital logic

  
 Output voltage appears on  the metal tabs in the picture above
  
 The Amanero might be faulty, remove it from the DAC and plug it into the Mac and see if the behavior changes.
  
 The stock Amanero USB board is powered by the USB bus.
  
 Not too expensive to replace.


----------



## penguin69

Thanks, b0bb.
  
 Yes, I removed the original I/V resistors using the rework tool.
  
 The crystek 950 sits on a rhea board, which in its turn sits on a socket allowing interchange of xo's. The awkward part of this is that my DAC already had a regulator 'mod' which meant I had to disable one of the pins on the DIP socket so that I could get the voltage feed from the regulator mod. But since the xo only uses three pins, I would be surprised if I have messed up anything here. I will double-check nonetheless. This is an older pic prior to a few mods, including the addition of the DIP board. The MH-DA003 I acquired had the 575 xo sat out of picture, on the extra regulator board which can just be seen in the bottom right corner. I could always remove this extra board and just take the original voltage source from close to the xo socket, but it seems to have worked ok prior to yesterday.
  

  
 Anyway, I will do some testing later today and tomorrow.
  
 If the USB board is the issue, I'm not too fussed as I was going to buy the new version anyway.
  
 Thanks as ever b0bb. I'm amazed I've even got this far, and without the mods you have suggested I would have sold the DAC on long ago due to the average stock SQ (IMO).


----------



## dacusb

Hi b0bb,
  
 I've been trying to contact Volent HK via email to enquire about the Amanero USB power supply, but have not received any feedback from them at all. I am wondering whether the said PS has been discontinued.
 Can you suggest any other boards as good replacements for Volent USB PS and what would be the mods needed?
 Thanking you


----------



## penguin69

Update on my side.
  
 One of the aftermarket regulators had come loose. (b0bb's tip about the blue LED's and locking made me notice that one was not on). The soldering had broken away. After some awkward resoldering, I managed to restore power.
  
 However, the orignal problem of no lock (and thus no sound) remains. I resoldered the Crystek 950X in case that was the problem. No joy. 
  
 It's almost certainly not the USB board, as I couldn't get any success with the digital coax input either.
  
 I'm close to ordering another unit.
  
 I will maybe first order another Crystek XO and see how I get on.
  
 Frustrating, after getting so far with all previous modifications.


----------



## Tomus4

b0bb said:


> The DC supply voltage is below 30V, this within acceptable limits for the Burson, contact them about the failures to get replacements.
> 
> The blue trimpot on the left channel may be faulty, given the sudden jump in output you are seeing, however 1.5mV is not going to cause any DC problems down stream.
> I do not expect that you will be able to reduce the offset any further on the left channel without component replacement.


 
 Alex from Burson wrote:
I am not sure about that. But this particular DAC chip is outputting excessive DC.
 
Cheers,
 
Alex 
   




 On 24 Feb 2017, at 4:21 AM, wrote:
  



> Hi,
> Do you think that problem is with this specific item oraz LKS Audio MH-DA003 generaly?
> 
> Best regards
> ...


----------



## b0bb

tomus4 said:


> Alex from Burson wrote:
> I am not sure about that. But this particular DAC chip is outputting excessive DC.
> 
> Cheers,
> ...


 
  
 ES9018 DC level with no signal is 1.65V
  
 As this voltage is present on both opamp input terminals this is known as the common mode voltage.
  
 This parameter is documented for the Ticha 994 and the stock OPA1612
  
Ticha994: Handles up to 12V
 http://www.sonicimagerylabs.com/products/product_images_docs/994Enh_Discrete_HD_OpAmp/994Enh_DiscreteOpAmp_Datasheet.pdf

  
OPA1612: Handles up to 13V (15V-2)
 http://www.ti.com/lit/ds/symlink/opa1612.pdf

  
 I think you should discontinue the use of the V5D as it is not able to handle a common mode voltage of 0.004V
 Burson did not supply this info on the V5 datasheet.


----------



## b0bb

dacusb said:


> Hi b0bb,
> 
> I've been trying to contact Volent HK via email to enquire about the Amanero USB power supply, but have not received any feedback from them at all. I am wondering whether the said PS has been discontinued.
> Can you suggest any other boards as good replacements for Volent USB PS and what would be the mods needed?
> Thanking you


 
  
 Other vendors are selling it on Ebay.
  
 This one is from Shenzen Audio
 http://www.ebay.com/itm/112189661866


----------



## b0bb

penguin140369 said:


> However, the orignal problem of no lock (and thus no sound) remains. I resoldered the Crystek 950X in case that was the problem. No joy.


 
  

  
 The pins on the XO socket are not coming out on the other side, if they are too short you may not have full contact on every layer of the PCB.
 You may have a hidden dry solder joint in there.
  
 Notice the pins for the opamp socket is clearly visible
  
 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.


----------



## dacusb

Hi b0bb,
  
 Thank you very much for your help.
 I will immediately place order for the PS board, the Antek transformer and all the parts to be swapped.


----------



## penguin69

b0bb said:


> The pins on the XO socket are not coming out on the other side, if they are too short you may not have full contact on every layer of the PCB.
> You may have a hidden dry solder joint in there.
> 
> Notice the pins for the opamp socket is clearly visible
> ...


 
  
 Thanks b0bb, excellent tip.
  
 The DIP socket I am using will not pass through one of the holes due to some kind of blockage. I don't know if this is down to the original modder leaving something there when moving the 575 xo to the discrete regulator board (discussed earlier in this thread) or whether it is debris from some of my earlier efforts. Anyway, I made some alterations to get around this and I am still not getting a lock.
  
 Further to this, one of the regulator boards from the original mod performed by a 3rd party has worked its way loose and so I no longer have power to one channel of the output stage. This is idential to the problem I corrected yesterday. It's a very fiddly correction, as two of the pins span a tiny resistor and the third goes to a fairly small contact where presumably the output of something like an LT1763 should be. These discrete regulator boards will likely come loose again as I continue to make alterations.
  
 Since correction of these issues is eating up all of my spare time, and with no guarantee of a positive outcome, I have put in an order for a replacement MH-DA003. That might sound a bit extreme, but I will at least have a much cleaner platform to work with, and the benefit of hindsight + experience.


----------



## b0bb

dacusb said:


> Hi b0bb,
> 
> Thank you very much for your help.
> I will immediately place order for the PS board, the Antek transformer and all the parts to be swapped.Some


 
 Some of the other cheaper Ebay listings do not have the Crystek clocks, you will have to spend another 75USD if you have to put them in after purchase.


----------



## Tomus4

b0bb said:


> I think you should discontinue the use of the V5D as it is not able to handle a common mode voltage of 0.004V
> Burson did not supply this info on the V5 datasheet.


 
 So are you suggest to change output opa to NewClassD DEXA Special Edition?
 What will be optimal DC value beetween 1-3 and 2-3 RCA pins?
  
 I have problem with remove PCB from the chassis. This small lamina in the AES/EBU socket make it impossible.
 I have tried to remove this lamina form the AES/EBU socket with no effect.

 How to deal with it?


----------



## b0bb

tomus4 said:


> So are you suggest to change output opa to NewClassD DEXA Special Edition?
> What will be optimal DC value beetween 1-3 and 2-3 RCA pins?
> 
> I have problem with remove PCB from the chassis. This small lamina in the AES/EBU socket make it impossible.
> ...


 
  
 I have no solid recommendation for the OPA going to the RCA sockets. The DC offset adjustment range did not change with the DEXA in the unbalanced converter position going to the RCA sockets.
  
 I have only used the DEXA for a few weeks, like the Burson, the documentation is missing many OPA parameters. Burson started failing after 4 months, the Burson in my later photos are the replacement set.
  
 In that position I have also tried the NJR MUSES01, Sparkos SS3602 and the Ticha994. The Ticha is the best but an expensive option, the DEXA is the second best.
  
 I paid 40USD on a sale, I will not pay the normal asking price.
  
 The back panel can remain attached to the PCB, I rework the board with the back panel still attached, it separates from the chassis cleanly once you remove the power socket and power switch.


----------



## dacusb

Hi b0bb,
  
 Can you reconfirm that all the parts as listed in the Bill of Materials for Amanero board powersupply mod in your post # 114 are still good to mod with the Amanero USB PS from Shenzhen Audio and sold on Ebay as indicated in your post # 507?
 Thank you


----------



## b0bb

dacusb said:


> Hi b0bb,
> 
> Can you reconfirm that all the parts as listed in the Bill of Materials for Amanero board powersupply mod in your post # 114 are still good to mod with the Amanero USB PS from Shenzhen Audio and sold on Ebay as indicated in your post # 507?
> Thank you


 

 Post a few pictures after you receive the card, the Ebay vendors sometimes change the board layout.
  
 Do not mod until the card is verified as working in the DAC.


----------



## dacusb

Hi b0bb,
  
 I will pur


b0bb said:


> Post a few pictures after you receive the card, the Ebay vendors sometimes change the board layout.
> 
> Do not mod until the card is verified as working in the DAC.


 

 Hi b0bb,
  
 I will post the pictures upon receipt of the card as per your recommendation.
 Thank you for your valuable hep.


----------



## dacusb

b0bb said:


> A couple of comments
> 1)The left one goes to the DAC, the other two are optional.
> 
> 2)The heatsinks have to be removed to properly mount the new regulator and to check for short circuits.
> ...


 
 Hi b0bb,
  
 After the installation of Tekdevice board is completed, one needs to reinstall the output filter cap. Am I right?
 Thanking you


----------



## dacusb

b0bb said:


> Latest addition, this is the NewClassD DEXA Special Edition
> http://www.newclassd.com/index.php?page=123&hv=1
> 
> This is a high bias (20mA) Class A opamp
> ...


 
 Hi b0bb,
  
 Is the latest version of Dexa opamp better in terms of sonic performance compared to the former version as offered by partsconnexion? the price is double thus is it worth to get the latest version?
 Thanking you for your kind explanation.


----------



## b0bb

dacusb said:


> Hi b0bb,
> 
> Is the latest version of Dexa opamp better in terms of sonic performance compared to the former version as offered by partsconnexion? the price is double thus is it worth to get the latest version?
> Thanking you for your kind explanation.


 

 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.


----------



## bballas

​somebody trial this LKS stuff ???


----------



## bballas

lt3042,tps7a4700 on Taobao,42,35 Rmb


----------



## abartels

bballas said:


> lt3042,tps7a4700 on Taobao,42,35 Rmb


 
  
 Very nice find!
  
  
 Can you please provide a link of those?
  
 Cheers 
	

	
	
		
		

		
			




  
 Alex


----------



## penguin69

b0bb said:


> The pins on the XO socket are not coming out on the other side, if they are too short you may not have full contact on every layer of the PCB.
> You may have a hidden dry solder joint in there.
> 
> Notice the pins for the opamp socket is clearly visible
> ...


 

 Hi b0bb, 
  
 I think I may have solved the original problem relating to the XO. I have an old analogue 'scope, I will use this to test. But first I must solve another problem.
  
 As mentioned in an earlier post, the aftermarket regulators that came with my unit have both broken away from the board and caused some damage. 
  

  
  
 These regulators replaced the 1763 IC. I say 'replaced', but from the pristine condition of the solder where the IC should be, it looks like my DAC never had the 1763 in this position in the first place. 
  
 As you can see I have temporarily removed the caps with my rework tool in order to facilitate resoldering of the regulator. There are, however, a couple of problems.
  
 1) In coming away from the board, the aftermarket regulator has taken with it - and broken - the very small resistor(?) just to the right of the leftmost removed capacitor (near what I think would be Pin 8 of the missing IC).
  
 2) The copper trace leading to the +ve of the rightmost removed cap has peeled away (not an insurmountable problem)
  
 For information purposes, this is a picture of one of the aftermarket regulators.
  


 If I remember correctly, you wrote earlier that there could be RF hum issues associated with such a design.
  
 I'm chancing my arm here, but maybe you could answer some or all of the following questions:
  
 1) Should I try to restore these aftermarket regulators or, instead, buy a couple of LT1763's? If the latter, then I think it could be right on the limit of my soldering skills.
  
 2) How can I replace the missing 'resistor'? I'm assuming it is a resistor, part of an RC combo, but it was actually so small that I couldn't tell what it was.
  
 3) The copper trace is slightly damaged at one end of this little resistor, so it would be helpful to know to what it connects, just in case I cannot repair the trace.
  
  
 I will admit that I have been very close to jettisoning this now damaged DAC and buying a new 'clean' DAC, but the masochist in me keeps bringing me back ...
  
 Thanks as always b0bb.


----------



## b0bb

penguin140369 said:


> I'm chancing my arm here, but maybe you could answer some or all of the following questions:
> 
> 1) Should I try to restore these aftermarket regulators or, instead, buy a couple of LT1763's? If the latter, then I think it could be right on the limit of my soldering skills.
> 
> ...


 

  
 A couple of comments
 1)The melted cap must be replaced, there is a substantial danger it will fail in the future and short out the power supply rail.
 2)The missing 0.01uF ceramic cap has to go back in to achieve the 20uV noise performance, it looks like 0805 or 1206 package (US measurement), measure the dimensions and find something suitable on Mouser, X7R or better dielectric.
 3)Torn trace can be replaced by a short segment of fine copper wire.
 4)Original I/V resistors are still in place, these have to be removed when using the Vishay resistors. Looks like you removed the I/V integrating cap, that needs to go back in.
  
 Here is the picture on mine, the integrating cap is the translucent white polystrene cap is on the left

  
 The LT1763 must be soldered in using solder paste and hot air, using a soldering iron is not recommended given the extent of the damage to the board.


----------



## penguin69

Many thanks as always, b0bb.
  
 1) I'll get the damaged cap replaced, great spot. 
  
 2) Thanks for identifying the 0.01uF cap, I will source a suitable replacement. In the picture, the northernmost terminal of this (missing) cap appears to connect to Pin 8 of the regulator. Are you able to determine what the _southernmost_ terminal connects to? I ask as I think the copper trace may be damaged here, and it may no longer be a suitable soldering point for terminating the 0.01uF cap.
  
 3) I've used the fine copper wire trick elsewhere on the board where the trace is damaged, I will do this again as instructed.
  
 4) Yes, I eased out the I/V cap with my rework tool, however this was only as a temporary measure in order to facilitate some awkward soldering around where the aftermarket regulator was located.
  
  
 I'll get hold of some soldering paste asap for the 1763 regulator insert. I didn't realise such material existed.
  
 As an aside, I think I'll turn down the temperature of both my soldering iron and the rework tool as my hand isn't the steadiest and I seem to be causing collateral damage as I try to 'improve' things.
  
  
 As already stated, if I can't recover the damage to this board, then I may acquire a new MH-DA003. If you had the choice, b0bb, would you try out the MkII version (the one with the ES9028 chips) or stick with the older model? Both are still available, it seems.


----------



## b0bb

penguin140369 said:


> 2) Thanks for identifying the 0.01uF cap, I will source a suitable replacement. In the picture, the northernmost terminal of this (missing) cap appears to connect to Pin 8 of the regulator. Are you able to determine what the _southernmost_ terminal connects to? I ask as I think the copper trace may be damaged here, and it may no longer be a suitable soldering point for terminating the 0.01uF cap.


 
 Not sure what you are getting at, post a photo with a markup of the area you are talking about
  
  


> If you had the choice, b0bb, would you try out the MkII version (the one with the ES9028 chips) or stick with the older model? Both are still available, it seems.


 
  
 The mods I have described are for the 9018. The 9028 is an unknown quantity.


----------



## penguin69

Hi b0bb
  
 Sorry for not being clear.
  
 I have marked up the image below.
  


 The green square shows the location point of one of the solder points for the missing 0.01uF cap. I cannot tell from the trace what it connects to. I would like to know this, because the solder point is quite damaged.
  
 Thanks.


----------



## penguin69

Hi b0bb, ignore the above request - after some clean-up the copper trace is still usable as a soldering point.


----------



## fjc36

Dear b0bb,
  
 LKS already announced in recent days of a debut MH-DA004, the 9038pro dual model, the price goes up to 9800 RMB. I wonder what the DIY enhancement works or not for not harsh sound. Specially major issue is on the XO model, 570 or 950? May be I should ask for a socket to ease the swap work of the LKS build and Head-Fi recommended. What is your suggestion? I guess it is a difficult question to answer. Your idea is appreciated any way.
  
  
 fjc36


----------



## b0bb

fjc36 said:


> Dear b0bb,
> 
> LKS already announced in recent days of a debut MH-DA004, the 9038pro dual model, the price goes up to 9800 RMB. I wonder what the DIY enhancement works or not for not harsh sound. Specially major issue is on the XO model, 570 or 950? May be I should ask for a socket to ease the swap work of the LKS build and Head-Fi recommended. What is your suggestion? I guess it is a difficult question to answer. Your idea is appreciated any way.
> 
> ...


 
 Post a link with the information.
  
 The MH-DA004 has not been officially announced.
  
 The best info I can find is the site below:
 http://nxtmarket.info/item/546362464272
  
 At a cost of  9900 RMB, this makes it about 1800-2000 USD after distribution overhead costs are added.
  
 The DAC itself looks like a variant of the MH-DA003MkII Discrete.
 DAC chips have heat sinks attached which is consistent with the 9038 having higher output current up to 128mA vs 32mA for the 9018
  
 The Digital part of the power supply is different (upper right on the photo)

  
 XO is the Crystek CCHD-575-50, the 50ppm version is the cheapest model in the 575 family.
 LKS should have spent the extra cash to get the 20 or 25ppm variant as they seem quite attached to this XO.
  
 The 575-50 made the MH-DA003 sound way too harsh, this made this dac marginally better than the Gustard X20 in unmodified stock form.
  
 I think LKS lost a lot of potential customers this way given the Gustard is 2/3rds the cost.
  
 The 4pin to 14pin  DIL socket footprint for a bigger XO is still there so replacing the 575 should not be a big issue should it become necessary.


----------



## fjc36

Dear 0b00,
 Thanks for the reply. LKS shows the new model of new DAC; 9038pro dual on the Tao Po net, so, it should be official. Your interpretation is correct. They do mention few points like upgrade the USB board than the original Amanero, that  add up the cost of RMB 600, 9400 to 9900.  They do mention about the current  increase from 30 mA to 100 mA according to the DAC 9018/9028 and 9038. So in MH-DA004, discrete I/V is supplied not as a option. OP is gone. The newest DAC and the discrete OP must increased the cost to 2000 RMB.
 LKS mentions redesign and upgrade the power supply. They insist on use CCHD-575, (They should have read this forum).  I like to ask to put a XO socket before delivery, and switch all WIMA to be MKP or KP grade. if this is the final debut, it is indeed more costly. Wish it is worthy. I could translate the Chinese here at vital part, if needed. Or you have a translation machine already.  What is the crystek XO you recommend? Why not let me  ask them to supply an extra XO during the purchase. The extra service and cost can be negotiated (two XO).


----------



## b0bb

fjc36 said:


> What is the crystek XO you recommend? Why not let me  ask them to supply an extra XO during the purchase. The extra service and cost can be negotiated (two XO).


 
  
 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.


----------



## penguin69

Thanks for the review, b0bb. Your comments, plus the very high output current of the new Sabre chips, have put me off upgrading to the 004 version.


----------



## b0bb

penguin140369 said:


> Thanks for the review, b0bb. Your comments, plus the very high output current of the new Sabre chips, have put me off upgrading to the 004 version.


 

 It is very early days yet for the 004, LKS official mu-sound site does not list this dac and its availability is currently limited to China only as far as I can tell.
  
 The output transistors would be running with a  bias current of between 50mA-70mA if it were to operate in Pure Class A over the entire output range, these transistors would be very warm to touch.
  
 I would be watching to see how this dac does in customers hands in terms of DC stability.
 The dac is assumed to be directly coupled from the 9038 to the output so it is quite important that the outputs remain as close to 0Volts as possible.
 (This was the case with with the 9018)
  
 The output transistors of the discrete opamp should have been mounted onto a common heatsink/heatspreader, this evens out the temp differences between the PNP and NPN transistors improving the DC offset.
 It also improves thermal coupling between the 2 sides of the differential output.
  
 This would have helped quite a lot in keeping thermal induced DC drift effects under control.


----------



## fjc36

So, I will hold my breath, and wait for whats going on. bobb explained well about the officials, restrict sells in China only not world wide, something odd.


----------



## b0bb

Below is a markup of the area around one opamp's output transistors.

  
 The transistors are very close to the electrolytic caps, lets hope these caps are rated to 105degC.
  
 The 2 transistors should ideally be on a common heatsink/heatspeader to reduce DC drift.
  
 Assuming a voltage of 15V across each transistor and a bias current of 70mA (0.07A),
 each transistor will be dissipating just over 1W,
 this gives a total dissipation of 4W for each channel, 8W for the whole dac.
  
 (The specs claim Class-A operation, I am wondering if the opamp truly operates in full Class-A over the entire range,
 because of the potential thermal issues here. I hope LKS did the right thing and reduced the supply voltage to the opamp.
 15V is the voltage used on the 9018)
  
 This will be an area to keep an eye on the temperature rise, the caps may be cooked by the heat over long term.
 Electrolytic caps have water in them, this will accelerate loss thru evaporation.
  
 The layout of the output stage is quite odd.
 Transistor package is TO-126/SOT-32 which has an exposed metal heat spreader on the transistor.
 On this LKS layout it is facing towards the caps, this directs the heat towards the caps and this seems counterproductive to me.
  
 Below is a picture of the TO-126 package


----------



## dacusb

b0bb said:


> Post a few pictures after you receive the card, the Ebay vendors sometimes change the board layout.
> 
> Do not mod until the card is verified as working in the DAC.


 

  

 Hi b0bb,
  
 Here are pictures of the card.
 Which parts do I need to mod, then?
 Thanking you for your help and assistance, so far.


----------



## Tomus4

b0bb said:


> ES9018 DC level with no signal is 1.65V
> 
> As this voltage is present on both opamp input terminals this is known as the common mode voltage.
> 
> ...


 
 I have info from Burson:
Hi Tomasz,
 
Our engineer reported that our V5 can have an input common voltage of up to 5V.
 
Best regards,
 
Alex
    *Burson Audio*| www.BursonAudio.com | info@bursonaudio.com 
*Supreme Sound Audio*| www.SSAudio.com.au | opamp@bursonaudio.com
 Follow Burson on Facebook and Twitter!


----------



## b0bb

tomus4 said:


> I have info from Burson:
> Hi Tomasz,
> 
> Our engineer reported that our V5 can have an input common voltage of up to 5V.
> ...


 
  
 That confirms the low DC tolerance of the V5D.
  
 Burson's is correct in not recommending the V5D for use in the LKS.
  


tomus4 said:


> 2017-02-23 1:21 GMT+01:00 Burson Sales <info@bursonaudio.com>:
> 
> 
> 
> ...


----------



## b0bb

dacusb said:


> Hi b0bb,
> 
> Here are pictures of the card.
> Which parts do I need to mod, then?
> Thanking you for your help and assistance, so far.


 

 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.


----------



## dacusb

b0bb said:


> 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

b0bb said:


> 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

kazcou said:


> 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
> ...


 

 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

tomus4 said:


> 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

penguin140369 said:


> 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

b0bb said:


> 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.


 

  


b0bb said:


> 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

b0bb said:


> 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.
> 
> ...




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

b0bb said:


> 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

penguin140369 said:


> Hi b0bb
> 
> Just revisiting this advice from you. I dug out my existing oscilloscope recently and found that it offers a measly 20MHz bandwidth.
> 
> ...


 
  
 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

b0bb said:


> 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.


----------



## b0bb

penguin140369 said:


> 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.


 
  
 Out of the box preformance sounds good.
  
 Do the vents extend up to the I/V output stage ?
  
 I am curious to see if the DC  offset remains stable,  this is the DC voltage between pins 2 and 3 on the XLR connector.
 It would be good if you can measure this every couple of weeks as the dac settles in.


----------



## penguin69

Hi b0bb
  
 No, the vents do not extend too far - see attached pic.
  

  
  
 As soon as my 'scope arrives I will start measuring the DC offset.


----------



## Whitigir

You should post over here too ! Welcome to the newest 9038Pro 

http://www.head-fi.org/t/840938/l-k-s-audio-mh-da004-dual-es9038pro-dac-van-dammes-double-impact/15#post_13385318


----------



## penguin69

After further extended listening today, I'm thinking that there is definitely something inherently 'right' about this DAC. It seems to have good DNA. The 003 in my opinion needed a lot of fixing.
  
 The question is whether the 004 is close to its potential, or whether extended modding will take it to the next level. 
  
 Interesting too is that it's not even burned in.
  
 I bet if b0bb were to sprinkle his magic dust on the 004, the result would be one of the best DAC's there is, irrespective of price tag.


----------



## Whitigir

penguin140369 said:


> After further extended listening today, I'm thinking that there is definitely something inherently 'right' about this DAC. It seems to have good DNA. The 003 in my opinion needed a lot of fixing.
> 
> The question is whether the 004 is close to its potential, or whether extended modding will take it to the next level.
> 
> ...




It uses many good components fit discrete class A . The modifications possibly can be done by using discrete regulators all around ? Lol but that would be hell lot of work and expensive. I already replaced stock Fuse to black label one  anything that helps or possibly be


----------



## penguin69

I changed all the voltage rectifiers out on the analogue side for higher quality  in the 003, that wasn't a difficult mod at all (and I'm not the most skilled). I haven't opened the lid of the 004 yet, but I'm sure there are a few things that can be done. I have some custom regulators which could improve on the stock ones. Maybe it's marginal gains, but it's good to have a hobby, and I've learned alot just from this thread! (38 pages now, nearly all about mods.)
  
 I'll take a peek tomorrow morning and post some pictures for the curious.


----------



## fjc36

Dear Englishman,
  
 I am interesting to witness the jansen capacitor that replace the X capacitor (YKWIM).  By the way, no offense for the title, I went to Sheffield to gain a PHD deg. from the Engineering Materials dept. (actually metallurgy dept. long ago). The master degs were obtained in USA. They are Physics, Materials Science, no electronics I am afraid.


----------



## b0bb

fjc36 said:


> Dear Englishman,
> 
> I am interesting to witness the jansen capacitor that replace the X capacitor (YKWIM).  By the way, no offense for the title, I went to Sheffield to gain a PHD deg. from the Engineering Materials dept. (actually metallurgy dept. long ago). The master degs were obtained in USA. They are Physics, Materials Science, no electronics I am afraid.


 
  
 +1
  
*penguin140369,*
  
 A few photos of the area around the XO and associated regulator would be appreciated.
  
 The Jensen caps I can see from the initial photos were used as the main powersupply reservoir caps.


----------



## penguin69

Hello both
  
 Definitely not an Englishman, I carry an Irish passport. 
  
 I took some photos today, but they are not high res due to a file transfer issue. If you need better quality from any of the pics, just shout and I will address.
  
 Again, I'm not sure whether I should post here or in the 004 thread. Maybe it's better here as this is predominantly a modding thread and there is some continuity in terms of product heritage.
  
*Caps and rectifiers - Analogue section*
  

  
 Even easier to mod this section than with the 003, due to a bit more spacing. 
  
  
*Digital side*
  

  
  
*Amanero board*
  

  
  
*Crystek 575 with the 9038's either side*
  

  
 As with the 003, there are holes for a 14 DIP board. 
  
  
*Regulator + Caps for the ES9038Pro*
  

  
*Another view of the same:*
  

  
  
*Output stage (balanced output in centre)*
  

  
  
*9038's and discrete I/V stage*
  

  
  
 Hope this is useful. Some of the components are obvious from the pictures for those who have worked with the 003. However, if you need me to further identify any of them then just shout.
  
 penguin140369 (a.k.a. 'Pat')


----------



## Whitigir

Damn! All of these sexy components make me drool


----------



## Roen

penguin140369 said:


> Hello both
> 
> Definitely not an Englishman, I carry an Irish passport.
> 
> ...


Is there anyway to verify that they are 38's under the heatsinks?


----------



## Whitigir

roen said:


> Is there anyway to verify that they are 38's under the heatsinks?




I knew someone would ask for this . Yeah, totally, remove the heatsink and look LoL


----------



## penguin69

roen said:


> Is there anyway to verify that they are 38's under the heatsinks?


 
  
 The manual says they are. Is there a good reason why they might not be?


----------



## Whitigir

penguin140369 said:


> The manual says they are. Is there a good reason why they might not be?




Because they are expensive, hard to implement correctly, and majority of other manufacturers had only been implementing 1x Single ES9038pro so far. LOL....anyways, those were just guesses. When it sound good to me, then it is good.


----------



## drez

Those heatsinks are probably held on with thermal epoxy.


----------



## b0bb

penguin140369 said:


> I took some photos today, but they are not high res due to a file transfer issue. If you need better quality from any of the pics, just shout and I will address.
> 
> Again, I'm not sure whether I should post here or in the 004 thread. Maybe it's better here as this is predominantly a modding thread and there is some continuity in terms of product heritage.


 
  
 Thanks that was useful.
  
 Most of the discussions here are about internal modification to the DAC so this is a good place to talk about the various internal components and what we can do to try and improve things.


----------



## b0bb

penguin140369 said:


> *Output stage (balanced output in centre)*
> 
> 
> 
> ...


 
 The caps directly behind the transistors in the I/V section are Nichicon Fine Gold
 http://www.nichicon.co.jp/english/products/pdfs/e-fg.pdf
  

  
 85 degC caps, so might need to keep an eye and/or put in something that has  a wider temperature range.
  
 Closeups of the Fine Gold.


----------



## b0bb

penguin140369 said:


> *Caps and rectifiers - Analogue section*
> 
> 
> 
> ...


 
  
 The filter and bypass caps for the XO regulator is the Nichicon MUSE probably type KZ.
  
 The MUSE series has a distinctive black and gold jacket.
 https://products.nichicon.co.jp/en/pdf/XJA043/e-kz.pdf
  
 Closeup:


----------



## b0bb

penguin140369 said:


> *Digital side*


 
  
 LKS added an additionally regulator, on the 003 there were 3 regulators on the Digital side, they are now 4 on the 004.
  
 I hope that is to split out the 3.3V digital and analog supplies to the 9038


----------



## b0bb

roen said:


> Is there anyway to verify that they are 38's under the heatsinks?


 
  
 Measure the DAC current output while being driven by a full scale sinewave signal.
  
 The peak values should be between 100-128mA, (70mA rms - 91mA rms)
  
 9018/9028 peak output current values are around 30mA.


----------



## b0bb

penguin140369 said:


> The manual says they are. Is there a good reason why they might not be?


 
  
 I would give LKS the benefit of the doubt, they delivered the 003 and 004, both of outstanding quality and I did not find any fake parts on the 003.
  
 Unfortunately, the part of the world where LKS is located is notorious for counterfeit semiconductors, some of these fakes are so convincing that the only way to be sure is to measure the device parameters.
  
 In the case of the 9038, the fullscale output current is a good indication of whether the part is genuine.


----------



## Whitigir

Nice! High quality Capacitors everywhere . So in a sense, to make sure of the DAC, we measure current from the output to see if it swing 100mA up to 128mA in operation ?

What are those transistors next to the fine-gold ? The DAC does not run that hot. Probably 40C Max, so I assume it could only reach up to 50C internally


----------



## penguin69

I personally do not see why LKS Audio would irrepairably damage their reputation by supplying fake parts.
  
 From what I can tell, the 9038 chip in implementation terms doesn't look such a huge a departure from the 9018, other than the management of the much higher current output, which is addressed through the total redesign of the I/V / Output stage using discrete parts. Those familiar with the internals of the 003 can see immediately that the 004 hasn't just been thrown together overnight. It's not an 003 with the new chips dropped in. It is a noticeable re-design in a number of areas.
  
 The 004 implements the ES9038Pro filter presets. These are not avaiable on the 9018. So when you select the 'FILT' button on the 004 remote, it would have to be a lie that you are scrolling through the various filters available. Similarly, the digital phase locked loop implementation on the 004 is more granular than that of the 003/9018 - that would also have to be a fake implementation.
  
 LKS have been designing for dual mono Sabre DAC's since the LKS Audio MH-DA002 (so 4-5 years, at least?), and have produced design revisions even within the 002 and 003 models (e.g. USB board), so it really shouldn't be seen as a huge challenge for them to implement the ES9038Pro. They are not starting from scratch.
  
 And as Whitigir has written, there is the sound. I'm not sure he has an 003 to compare to, but I can assure you that there is quite a significant difference in sound between the stock 003 and stock 004.


----------



## Whitigir

Penguin, Do you have stalling issues ? When I first turned on the unit for 10 minutes or so and feeding it using Flac or DSD and it would stall for a second here and there randomly ? During this time, the unit will display Source input as "unlocked" ? Possibly problem with the Amernero module ?


----------



## penguin69

whitigir said:


> Penguin, Do you have stalling issues ? When I first turned on the unit for 10 minutes or so and feeding it using Flac or DSD and it would stall for a second here and there randomly ? During this time, the unit will display Source input as "unlocked" ? Possibly problem with the Amernero module ?


 
  
 I've not experienced any stalling issues myself using the 004.
  
 You could start first with setting the DPLL bandwidth to its highest (most tolerant) setting - BW15 - to see if it is a locking issue on the PLL. If that cures it then great, but there is a theoretical reduction in SQ for using a higher setting. Personally speaking, my ears have never heard the difference.
  
 Another possibility could be that digital buffering somewhere in the chain cannot keep up with replay. I always used cabled Ethernet to limit network latency/buffering issues. But even with cabled Ethernet I've had buffering issues with DSD. Never with PCM, though. 95% of the music I play is Tidal lossless, and I can't remember the last time I got a drop out. For the record, my broadband speed is a moderate 30MBps. No wifi is used, as already mentioned.
  
 The Amanero 384 board in the 004 is good quality (better than the version I had in my 003) so I would be surprised if that is the culprit here.
  
 I'm sure b0bb could provide a better and more accurate diagnosis, I'm something of a Luddite here.


----------



## b0bb

whitigir said:


> So in a sense, to make sure of the DAC, we measure current from the output to see if it swing 100mA up to 128mA in operation ?


 
  
 If you playback an uncompressed audio file (flac/wav/alac) containing a sinewave at full scale, the voltage across the I/V resistor divided by the resistance is the RMS current, multiply that by 1.414 to get the peak output current.
  
 If it sinewave is below 100Hz any ordinary multimeter on the AC range can be used.
  
  


whitigir said:


> What are those transistors next to the fine-gold ?


 
  
 Post a closeup of the transistors where the part numbers are legible and I may be able to tell you more.
  
  


whitigir said:


> The DAC does not run that hot. Probably 40C Max, so I assume it could only reach up to 50C internally


 
  
 The lifespan of the cap is dependent on temperature and can be predicted with reasonable accuracy.
  
 Cornell Dubilier/Malllory had a good reference on this. Coverage of capacitor lifetimes begins on page 14
 http://www.cde.com/resources/catalogs/AEappGUIDE.pdf
  

  
 For the purposes of this discussion Mv=1 Ta=50
  
  
*Nichicon FG/Fine Gold (http://www.nichicon.co.jp/english/products/pdfs/e-fg.pdf)*
  
 85degC/1000h (Tm=85 Lb=1000)
 Operating Lifetime Lop = 11314h, approx 15 months.
  
  
*Panasonic FM (http://www.mouser.com/ds/2/315/ABA0000C1018-947496.pdf)*
  
 105degC/5000h (Tm=105 Lb=5000)
 Operating Lifetime Lop = 226274h, approx 309 months.
  
  
 Panasonic FM is a commonly used cap in audio applications. LKS is using them in the 004.
  
 There is a 20X difference in lifetime, the Fine Golds are a candidate for replacement for something better.


----------



## b0bb

penguin140369 said:


> I've not experienced any stalling issues myself using the 004.
> 
> You could start first with setting the DPLL bandwidth to its highest (most tolerant) setting - BW15 - to see if it is a locking issue on the PLL. If that cures it then great, but there is a theoretical reduction in SQ for using a higher setting. Personally speaking, my ears have never heard the difference.
> 
> ...


 

 If the 004 has an AUTO DPLL setting, that should be used to see if it solves the problem.
  
 There are 2 Amanero options available when ordering the 004, the standard version is bus powered, if the host cannot supply  enough power or is marginal,  dropouts can happen.
  
 To exclude the Amanero as the problem source, try the SPDIF inputs.


----------



## penguin69

b0bb said:


> If the 004 has an AUTO DPLL setting, that should be used to see if it solves the problem.
> 
> There are 2 Amanero options available when ordering the 004, the standard version is bus powered, if the host cannot supply  enough power or is marginal,  dropouts can happen.
> 
> To exclude the Amanero as the problem source, try the SPDIF inputs.


 

 b0bb, unfortunately there is no AUTO setting on the 004. (There is, however, a NOBW setting, alongside the BW01 - BW15 settings. The manual doesn't explain what this setting does.)


----------



## b0bb

penguin140369 said:


> b0bb, unfortunately there is no AUTO setting on the 004. (There is, however, a NOBW setting, alongside the BW01 - BW15 settings. The manual doesn't explain what this setting does.)


 
  
 BW15 DPLL bandwidth appears to be the most jitter tolerant for the 004.
  
 On the 003, dropouts on low DPLL bandwidth appear at high sampling rates, on 44.1k material I can use any setting, on 384k DXD it has to be on AUTO or HBW on the 003.
  
 I suspected the Amanero may be running out of CPU cycles at the higher sampling rates, so the jitter performance worsens at high sampling rates requiring a higher timing tolerance aka higher DPLL BW.
  
 I bought the Singxer F-1 which has the XMOS XU-208 to try this out.
 The XU-208 has a much faster CPU and most of the dropout problems with DXD went away, on low DPLL bandwidths however the SQ was so much poorer that I went back to using the Amanero.
  
 The F-1 has an Amanero compatible I2S header interface.
  
 I might revisit this on less complicated XU-208 cards from Singxer like the Q-1 or C-1 (Just the XU208 minus the isolator and reclocker bits)


----------



## Whitigir

Mine was ordered with upgraded Amanero card. This stalling issues only appears in the first 10-15 minutes when the unit was still cold. There are definitely a lot of nichicon fine gold Capacitors inside. Shall we replace them all with Jansen or black gate for better longevity and performances ?


----------



## b0bb

whitigir said:


> Mine was ordered with upgraded Amanero card. This stalling issues only appears in the first 10-15 minutes when the unit was still cold. There are definitely a lot of nichicon fine gold Capacitors inside. Shall we replace them all with Jansen or black gate for better longevity and performances ?


 

 If the SPDIF input does not suffer the same problem it is narrows it down to the Amanero. The module detaches from the DAC and see if you can get a warranty replacement.
 Similarly, verify your playback source is in good order.
  
 Once you start to pull out the caps, warranty is void.
  
 I did not see Jensen making anything small enough to replace the Nichicon FGs. ( I assume you mean this Jensen http://www.jensencapacitors.com)
 Post a link if you see ones of the right size.
  
 Blackgates stopped production 10 years ago, I would avoid old stock as the electrolyte in the caps would have degraded by a substantial margin.
  
 Just about every manufacturer in audio including LKS is using Panasonic FMs for general powersupply  decoupling duty.
 It works and does not color the sound, I see no reason to change.
  
 Nichicon recently started making the audio grade KA series (http://www.mouser.com/pdfdocs/NichiconKAaudiocapsdatasheet.pdf)
 Mouser sells them and I use it as an alternative for a slightly more lush presentation.
 Operating lifetime is about 40% that of the FM, about 120 months@50degC, that is 10 years.


----------



## Whitigir

Thanks b0bb. My source is all good as I am using Walkman wm1Z with a docking cradle and upgraded USB which I have never had this problem on the Sony TA-ZH1ES with it. It definitely only happen in the first 10 minutes or so when the unit was not warm enough, and randomly, when it happens the unit display "Unlocked" for the sources display, like it was trying to re-clock or doing some short to the digital signals or it could have been running out of power like you said previously. I had emailed support to see if they could help.

this stalls is similar to when I swap Bandwidth from 01 to 15 or so, once the BW is swapped, the unit stalls for 0.5 second or so. I tried to ramp it up to BW05-07 and it still does the same thing when it is cold randomly


----------



## penguin69

As b0bb says, an S/PDIF test might be a quick way to isolate the problem. I have a couple of USB to S/PDIF converters at home which I have often used to get around USB issues (dating from the time that I used a Raspberry Pi as my main source). Cheap converters can be had off ebay for $5-10 and can sit inline, serving as a useful test tool if there is no S/PDIF available from your source.
  
 I have a spare Amanero board which you are more than welcome to have, however since you are under warranty you should clearly be entitled to a replacement if this is indeed the source of your problem.
  
 FWIW, my 003 had a slight fault whereby it would occasionally provide a signal for just one channel upon startup. It was usally remedied with a reboot of the music player and the 003. Not ideal, but I could live with it, and since the 003 I had acquired had already been slightly modified by a 3rd party, I had no recourse to warranty.


----------



## penguin69

FYI Whitigir - I've been testing the 004 for an hour or so with the BW01 setting (least tolerant). Zero drop-outs. This is streaming Tidal lossless via Audirvana+ over USB, not as tough a workout as DSD would give.
  
 I'll keep this setting on (no reason not to, it theoretically provides the best SQ) and monitor.


----------



## penguin69

And I have to add that the unit to my ears is just sounding better and better as it burns in. It delivers the additional 'grip' that a dual mono architecture should provide over a single chip.


----------



## Tomus4

b0bb said:


> The DC supply voltage is below 30V, this within acceptable limits for the Burson, contact them about the failures to get replacements.
> 
> The blue trimpot on the left channel may be faulty, given the sudden jump in output you are seeing, however 1.5mV is not going to cause any DC problems down stream.
> I do not expect that you will be able to reduce the offset any further on the left channel without component replacement.


 
  
 Hi b0bb,
  
 I replaced trimpots by Vishay recomeded by you. I replaced caps near them by Tantalum yellow as well. And I have still offset like before. I have done some other measurements between ground and points on the pictures below:

 With ticha the offset is around 3,8mV - left channel
 What to do to reduce left channel offset?
 Do you have schema of I/V and output stage of LKS?


----------



## b0bb

tomus4 said:


> Hi b0bb,
> 
> I replaced trimpots by Vishay recomeded by you. I replaced caps near them by Tantalum yellow as well. And I have still offset like before. I have done some other measurements between ground and points on the pictures below:
> 
> ...


 
  
 You have eliminated the trimmer and the cap as culprits, this means your are at the limit of adjustability.
  
 LKS did not publish a schematic, below is the reference version, the I/V is almost the same the unbalanced output is different on the LKS.


----------



## Tomus4

b0bb said:


> You have eliminated the trimmer and the cap as culprits, this means your are at the limit of adjustability.
> 
> LKS did not publish a schematic, below is the reference version, the I/V is almost the same the unbalanced output is different on the LKS.


 
 I marked items from schema in the picture. Please let me know if am I correct:

 There are no R3 and R15 in the LKS. Where is in the schema cap "?" ?
 What is root cause of the limit of adjustability? Why in the right channel it is possible to set 0mV DC on the output of both opa (U2, U3) but in the left channel no?
 What value of offset you have in your DAC? 
 I have TX2575 249R00 0.05% and poliester 1% 220nF (brand MIAL) cups to replaced C2, C7 and ?. Cups I measured and have some pair 220, 222, 223 and 224 nF. Do you think replacement can help to move limit of adjustability of the offset?


----------



## b0bb

tomus4 said:


> There are no R3 and R15 in the LKS. Where is in the schema cap "?" ?


 
  
 "?" cap is not on the schema, it is specific to the LKS and is used to match the output impedance of the 9018 to the input impedance of the I/V opamp.
  
  


tomus4 said:


> What is root cause of the limit of adjustability? Why in the right channel it is possible to set 0mV DC on the output of both opa (U2, U3) but in the left channel no?
> What value of offset you have in your DAC?


 
  
 The trimmer alters Vref which is part of the output current sensing system on the 9018, this is just the chip to chip differences between the two 9018 chips.
 My DAC varies between 1.5-2.5mV.
 If you want a more specific answer contact ESS.
  
  


tomus4 said:


> I have TX2575 249R00 0.05% and poliester 1% 220nF (brand MIAL) cups to replaced C2, C7 and ?. Cups I measured and have some pair 220, 222, 223 and 224 nF. Do you think replacement can help to move limit of adjustability of the offset?


 
  
 Replacing the caps will not help. The stock caps are Film+foil WIMA KP polypropylene, you would be going backwards in using polyester which has worse dielectric properties.
 If you are looking for something better then stock use film+foil polystyrene like I did on mine


----------



## Tomus4

b0bb said:


> "?" cap is not on the schema, it is specific to the LKS and is used to match the output impedance of the 9018 to the input impedance of the I/V opamp.
> 
> *I drew C? on the schema and wrote value of caps and TX2575 . Is it correct? *
> 
> ...


----------



## b0bb

*Output stage*
 The I/V output is passively filtered for balanced and goes into differential to single-ended converter + filter stage to provide the unbalanced output.
 There is no output stage I can see beyond this.
  
*Using the V5D*
 Burson has made it clear about not using this in the LKS 003, you should discuss this with Burson to get a final answer.
  
*Polystyrene caps.*
 The picture shows the correct polystyrene caps


----------



## Whitigir

Just to clarify , these 003-004 is running bandwidth 13 as default ? I got the message from LsK saying that to stop the stalls on cold start, I should set the BW to more than 10


----------



## Tomus4

Hi b0bb,
  
 My intention is to create schema of I/V and RCA stage. Base on your information from this forum I drew I/V stage - please let me know if it is correct:

 I have a request for you to drew RCA stage. Could you?


----------



## b0bb

tomus4 said:


> Hi b0bb,
> 
> My intention is to create schema of I/V and RCA stage. Base on your information from this forum I drew I/V stage - please let me know if it is correct:
> 
> I have a request for you to drew RCA stage. Could you?


 

 I did not fully trace the rca side.
  
 The cap values  are in picofarads not nanofarads.
 The 4 resistors around the balanced output need to back in to make the filter functional.
  
 "C?" is 100pf from memory, double check this.


----------



## Tomus4

b0bb said:


> I did not fully trace the rca side.
> 
> The cap values  are in picofarads not nanofarads.
> The 4 resistors around the balanced output need to back in to make the filter functional.
> ...


 
 You are right - 4  resistors 1,05k back.

  
 C? changed to C1 - has 100pF:

  
 I have not 100pF polystyrene caps.
 I have 100pF CY06C101F Corning Glass Works CGW. Do you thing it is good place for it? Or I should look for 100pF polystyrene caps? What is your experience with Glass caps in this place?


----------



## b0bb

tomus4 said:


> I have not 100pF polystyrene caps.
> I have 100pF CY06C101F Corning Glass Works CGW. Do you thing it is good place for it? Or I should look for 100pF polystyrene caps? What is your experience with Glass caps in this place?


 
  
 Corning glass caps sound much worse, very bright etched sound in this position.
  
 The 100pF cap is damaged with white inner plastic material showing, it should be replaced.


----------



## fjc36

*Ｄｅａｒ　Ｉｒｉｓｈｍａｎ： *
*When will ｙｏｕ start ｉｍｐｌａｎｔ 950　ＸＯ？Ｈｏｗ　ｌｏｎｇ　ｗｉｌｌ　ｙｏｕ　ｄｅｃｉｄｅ　ｔｏ　ｔｅｓｔ　ｔｈｅ　ｓｏｎｉｃ　ｅｆｆｅｃｔ？*


----------



## penguin69

b0bb said:


> Out of the box preformance sounds good.
> 
> Do the vents extend up to the I/V output stage ?
> 
> ...


 

 Hi b0bb
  
 My Hewlett Packard Oscilloscope arrived from the US finally. I plugged it in (using a 230v-110v converter) and connected the probes to pins 2 and 3 on the XLR connector of the DAC, as requested.
  
 Now the downside. The 'scope arrived with alll the programming material in a binder, but not the standard user pages.
  
 I assumed it would be common sense to work everything out, having quickly found how to adjust the time on the x-axis. But I was not able to find away to refine the voltage reading on the 'y' Axis.​
  


 The above reading was achieved using the 'auto-scale' button. 
  
 It's a nice thing, but I guess it will take me a bit of trial and error to get it working. Maybe I can source a manual from somewhere else. But I think it's a pretty old machine. For the record, it's a HP 54503A 500Mhz unit.


----------



## penguin69

Update: I found a Front Panel manual on ebay for $25. I may order it, but am pretty bummed at having to pay the extra when my machine was sold as 'with manual'.
  
 I also just found a free 'quick start' pdf online for the lower spec 54501 scope. It seems to cover the 54503 also - promising.


----------



## b0bb

penguin140369 said:


> Update: I found a Front Panel manual on ebay for $25. I may order it, but am pretty bummed at having to pay the extra when my machine was sold as 'with manual'.
> 
> I also just found a free 'quick start' pdf online for the lower spec 54501 scope. It seems to cover the 54503 also - promising.


 
  
 Front panel manual below
 http://bama.edebris.com/manuals/hp/54503a/
  
 According to the document above this is a sampling scope of 20Msamples/s, the true bandwidth is 10Mhz for sine waves, 4Mhz for square waves. The repetitive sampling feature is not useful for general electronics debugging work.
  
 BTW The DC offset measurement can be done with an ordinary multimeter. The sinewave on the screen looks pretty distorted.


----------



## penguin69

T​hanks b0bb.
  
 It's pretty frustrating that the 'scope isn't going to be fit for purpose. I probably should have done more research on the spec before buying it. I blindly assumed that the 500Mhz (which is even part of the unit name) was the sample rate. Oh well, you live and learn.
  
 I'll get a multimeter on the balanced out.


----------



## penguin69

fjc36 said:


> *Ｄｅａｒ　Ｉｒｉｓｈｍａｎ： *
> *When will ｙｏｕ start ｉｍｐｌａｎｔ 950　ＸＯ？Ｈｏｗ　ｌｏｎｇ　ｗｉｌｌ　ｙｏｕ　ｄｅｃｉｄｅ　ｔｏ　ｔｅｓｔ　ｔｈｅ　ｓｏｎｉｃ　ｅｆｆｅｃｔ？*


 

 Ha ha!
  
 It will be at least 3-4 weeks ... I'm letting the unit burn in first. Also, I am only home about 5-6 days a month at the moment.


----------



## penguin69

whitigir said:


> this stalls is similar to when I swap Bandwidth from 01 to 15 or so, once the BW is swapped, the unit stalls for 0.5 second or so. I tried to ramp it up to BW05-07 and it still does the same thing when it is cold randomly


 
  
 FYI - I had my first drop-outs like yours today.
  
 This was after setting the bandwidth to BW01 from startup. I moved it to BW10 and it stopped.
  
 After a minute or so, I returned it to BW01 and all was well.
  
 Just a punt, but maybe a component is still coming up to optimal working temp on startup? The XO?


----------



## Whitigir

penguin140369 said:


> FYI - I had my first drop-outs like yours today.
> 
> This was after setting the bandwidth to BW01 from startup. I moved it to BW10 and it stopped.
> 
> ...




The way it works, I think there are 2 possibilities 

1/ it automatically adjust the buffing speed

2/ Only when it is cold, the buffing speed will be automatically adjust (stalled)

Idk....either way, I turn it on for 5-10 minutes, and then play music lol


----------



## penguin69

The 003 had an 'auto-adjust' bandwidth setting (which I used to use), but the 004 doesn't have that.
  
 I'll set mine to BW15 for start-up and then crank it up to BW01 after a few minutes. I personally don't hear much if any difference.


----------



## Whitigir

i think I will just leave mine at 10 and stop being bothered by it. Thought it reminds me of tube amps  which I will have to get once more


----------



## fjc36

It is perfectly all right for a month to wait. Cheers.


----------



## Tomus4

b0bb said:


> Corning glass caps sound much worse, very bright etched sound in this position.
> 
> The 100pF cap is damaged with white inner plastic material showing, it should be replaced.


 
 100pF is ok - It was rosin. But I will relace it - waiting for  polystyrene caps.
 I have good news. I replaced most components and it solved problem with offset in left channel. I have max 0,1...0,3 mV in both channel now. I will check it after warming up.
 I measured resoldered components: resistors 249, 249, 249, 248 ohm, caps: 223, 225, 226, 227 pf.
 I have 249,1 ohm restsors and 224pf  polystyrene caps now.
 This is my dac now:


  
 Thank you very much b0bb for support!!!.You have a big beer from me. Give me your address and I will send you my favorite from my country.


----------



## b0bb

tomus4 said:


> Thank you very much b0bb for support!!!.


 
  
 You are welcome, changing the 575-50 XO will give you much better midrange and take the edge off the high frequency response, less sibilance.
  
 The TX2575s increases the transparency at the cost of making the presentation quite dry and etched if the 575-50 is left in place.


----------



## Tomus4

b0bb said:


> You are welcome, changing the 575-50 XO will give you much better midrange and take the edge off the high frequency response, less sibilance.
> 
> The TX2575s increases the transparency at the cost of making the presentation quite dry and etched if the 575-50 is left in place.


 
 That is right - I hear now more hight frequency and hiss. I read somwere dry and etched of TX2575 is reduced after warm up. Is that true?
 Now I will order:
 http://tekdevice.com/chapter2/index.php?route=product/product&path=25_54&product_id=139 (BTW what do you think about http://www.pulsarclock.com/Power.html)
 and Pulsar Clock.
  
 After 2 days unfortunately offset rise up. I try to set up a few times, but always it achieve about 1,5..2.2mV in left channel and 0,5 ... 0,6 mV in right. What is better - difference between XLR pin 2 and 3 is about 0,3 ...0,4mV. Before replacement was around 4mV


----------



## b0bb

tomus4 said:


> That is right - I hear now more hight frequency and hiss. I read somwere dry and etched of TX2575 is reduced after warm up. Is that true?
> Now I will order:
> http://tekdevice.com/chapter2/index.php?route=product/product&path=25_54&product_id=139 (BTW what do you think about http://www.pulsarclock.com/Power.html)
> and Pulsar Clock.
> ...


 

 TX2575 take 7-10 days to settle in and the sound will smooth out by a small degree, it is not sensitive to temperature, one of the main reasons I chose it to avoid temp drift effects from the resistor self heating. The 9018 runs a fairly large current, so  effects of resistive heating needs some attention.
  
 The Tekdevice in the link has the screw mounting holes too high up, you will need to drill a new hole in the heatsink, it must be attached to a heatsink if you use if to replace the 317s
  
 Pulsar is expensive at 400 Euros and is not available for sale in every country, contact Pulsar to verify.


----------



## Tomus4

b0bb said:


> TX2575 take 7-10 days to settle in and the sound will smooth out by a small degree, it is not sensitive to temperature, one of the main reasons I chose it to avoid temp drift effects from the resistor self heating. The 9018 runs a fairly large current, so  effects of resistive heating needs some attention.
> 
> The Tekdevice in the link has the screw mounting holes too high up, you will need to drill a new hole in the heatsink, it must be attached to a heatsink if you use if to replace the 317s
> 
> Pulsar is expensive at 400 Euros and is not available for sale in every country, contact Pulsar to verify.


 
 Tekdevice should be 5V, right? It supply clock's and 9018's LT1763, isn't it?


----------



## justbenice

b0bb said:


> *Output stage*
> The I/V output is passively filtered for balanced and goes into differential to single-ended converter + filter stage to provide the unbalanced output.
> There is no output stage I can see beyond this.
> 
> ...


 
 Dear Boob,
 I guess the main reason that we could not use V5D in this LKS DAC because the board have 17 near 18volt input the opamps, but the V5D only work at 15volt max. So are there anyway to fix this? Can we mod the board so it will supply only 13volt to the opamps?


----------



## Tomus4

Hi b0bb,
  
 A few posts ago someone showed on ebay this regulator http://www.ldovr.com/product-p/tps7a4700-lm31x.htm as alternative for Tekdevice .
 I will take this - it looks not worse than Tekdevice .
 This manufacturer sells http://www.ldovr.com/product-p/lt3045-s.htm (0,8 uV noise!!) as well. What do you think about using this regulator for oscilator's and 9018's power supply? 
  
 justbenice,
 b0bb is offline so I would like to inform you that problem with V5 is because offset of LKS. You can mesure it on the XLR socket pins.
 In the left chanel, before mod, I had 4mV and V5 damaged twice. In the right channel I had and have now 0..0,5mV and V5 damaged never. Now I have offset around 1,5 in left channel and waitiing for info from Burson if I can use it now. Supply volatge for opamps in the LKS is 14,9V so this is no problem


----------



## justbenice

tomus4 said:


> justbenice,
> b0bb is offline so I would like to inform you that problem with V5 is because offset of LKS. You can mesure it on the XLR socket pins.
> In the left chanel, before mod, I had 4mV and V5 damaged twice. In the right channel I had and have now 0..0,5mV and V5 damaged never. Now I have offset around 1,5 in left channel and waitiing for info from Burson if I can use it now. Supply volatge for opamps in the LKS is 14,9V so this is no problem


 
  
 Hi Tomus4,
  
 why you can have 14.9 volt in the board supply volt ? Mine is 16.8 or 17volt  
 Yes my V5D has damge 1 time in the left channel too. I am using V5i now and it work well. But the V5D better than the V5i alot so i do really want to use V5D.


----------



## Tomus4

justbenice said:


> Hi Tomus4,
> 
> why you can have 14.9 volt in the board supply volt ? Mine is 16.8 or 17volt
> Yes my V5D has damge 1 time in the left channel too. I am using V5i now and it work well. But the V5D better than the V5i alot so i do really want to use V5D.


 
 Maybe you measure it in wrong place. I measure it on the opa.
  
 Let's try DEXA opa - b0bb wrote about this some pages before.


----------



## justbenice

tomus4 said:


> Maybe you measure it in wrong place. I measure it on the opa.
> 
> Let's try DEXA opa - b0bb wrote about this some pages before.


 
 Hi,
  
 I  take out the opa and measure between the pin 4(-)  and pin 7 (+) in the board opa socket ,it show 16.8volt. is it right ?
  
 Thank you!


----------



## Tomus4

8+ 4- - between these two should be 29,8
 please provide DC between 1-2, 1-3 and 2-3 XLR pins


----------



## justbenice

tomus4 said:


> 8+ 4- - between these two should be 29,8
> please provide DC between 1-2, 1-3 and 2-3 XLR pins


 
  
 Thank you.
 8+ and 4- of mine show 31 volt. i
 XLR 1-2 1-3 and 2-3  show arround 225-226mv (left and right same)
  
 Do you think there are normal?


----------



## Tomus4

justbenice said:


> Thank you.
> 8+ and 4- of mine show 31 volt. i
> XLR 1-2 1-3 and 2-3  show arround 225-226mv (left and right same)
> 
> Do you think there are normal?


 
 8+ and 4- of mine show 31 volt. i - should be below 30. what is between 8 and ground and 4 and ground?
  
 XLR 1-2 1-3 and 2-3  show around 225-226mv - should be less then 4mV
 Please try set up it using blue trimpot (or black if you change it)


----------



## b0bb

justbenice said:


> Thank you.
> 8+ and 4- of mine show 31 volt. i
> XLR 1-2 1-3 and 2-3  show arround 225-226mv (left and right same)
> 
> Do you think there are normal?


 

 31V is slightly on the high side, mine is 14.8V and -14.9V.
  
 Burson has asked that the V5D not be used on the LKS 003, you might not be able to get warranty replacement if breaks again.
  
 You can turn down the voltage, the adjustment pot is next to the heatsinks on the powersupply
  
 226mV DC offset is quite high, this should be turned down, pots are near the DAC chips.


----------



## b0bb

tomus4 said:


> Tekdevice should be 5V, right? It supply clock's and 9018's LT1763, isn't it?


 

  Correct on both questions.


----------



## b0bb

tomus4 said:


> Hi b0bb,
> 
> A few posts ago someone showed on ebay this regulator http://www.ldovr.com/product-p/tps7a4700-lm31x.htm as alternative for Tekdevice .
> I will take this - it looks not worse than Tekdevice .
> This manufacturer sells http://www.ldovr.com/product-p/lt3045-s.htm (0,8 uV noise!!) as well. What do you think about using this regulator for oscilator's and 9018's power supply?


 
 LT3045 supplies up to 500mA, this is borderline for the DAC, the Tekdevice supplies 2X the current.


----------



## Tomus4

b0bb said:


> LT3045 supplies up to 500mA, this is borderline for the DAC, the Tekdevice supplies 2X the current.


 
 I am thinking about replacing based on LT1763 onboard regulators for oscillator only or oscillator and 9018 (5 items)


----------



## justbenice

b0bb said:


> 31V is slightly on the high side, mine is 14.8V and -14.9V.
> 
> Burson has asked that the V5D not be used on the LKS 003, you might not be able to get warranty replacement if breaks again.
> 
> ...


 
  


tomus4 said:


> 8+ and 4- of mine show 31 volt. i - should be below 30. what is between 8 and ground and 4 and ground?
> 
> XLR 1-2 1-3 and 2-3  show around 225-226mv - should be less then 4mV
> Please try set up it using blue trimpot (or black if you change it)


 
  
  
 Thank you Tomus4 and mr Great b0bb ,
  
 With your help, i managed to trim down the XLR 1-2, 1-3, 2-3 to 0.9mV 
 About the volt between pin 4-8 of opamps, i turn all the way of 2 trimpot near the heatsink untill i hear "click" in the trimpot but it only can turn the volt to 25volt, could not make it to below 25v  is it ok?


----------



## Tomus4

justbenice said:


> Thank you Tomus4 and mr Great b0bb ,
> 
> With your help, i managed to trim down the XLR 1-2, 1-3, 2-3 to 0.9mV
> About the volt between pin 4-8 of opamps, i turn all the way of 2 trimpot near the heatsink untill i hear "click" in the trimpot but it only can turn the volt to 25volt, could not make it to below 25v  is it ok?


 
 You should measure between 4 and GND to set -14,9 and 8 and GND to set 14,9. One trimpot is for - and another for + .


----------



## b0bb

justbenice said:


> About the volt between pin 4-8 of opamps, i turn all the way of 2 trimpot near the heatsink untill i hear "click" in the trimpot but it only can turn the volt to 25volt, could not make it to below 25v  is it ok?


 
 Make sure pin4 and ground is -12.5V , pin 8 and ground is +12.5V.
  
 The large metal body of the rca socket is a suitable ground point.
  
 Reducing the opamp power supply will reduce the performance of the Ticha994, so I consider this exercise to be a really poor choice.


----------



## justbenice

b0bb said:


> Make sure pin4 and ground is -12.5V , pin 8 and ground is +12.5V.
> 
> The large metal body of the rca socket is a suitable ground point.
> 
> Reducing the opamp power supply will reduce the performance of the Ticha994, so I consider this exercise to be a really poor choice.


 
 So how many volt should be good for the Ticha?


----------



## Tomus4

b0bb said:


> Make sure pin4 and ground is -12.5V , pin 8 and ground is +12.5V.
> 
> The large metal body of the rca socket is a suitable ground point.
> 
> Reducing the opamp power supply will reduce the performance of the Ticha994, so I consider this exercise to be a really poor choice.


 
 b0bb
 dexa has Voltage Range: +/- 5V to +/- 25V, 994Enh-Ticha - +10V to +24V
 Are you try to set up power supply over 15V to check how its work?


----------



## b0bb

justbenice said:


> So how many volt should be good for the Ticha?


 

 Keep it at ±15V or higher. Above ±18V you will need to keep an eye on the temperature, the optional heatsinks may be needed.


----------



## b0bb

tomus4 said:


> b0bb
> dexa has Voltage Range: +/- 5V to +/- 25V, 994Enh-Ticha - +10V to +24V
> Are you try to set up power supply over 15V to check how its work?


 

 The Dexa + Ticha will consume around 100mA, this borderline for power, if the voltage is increased too much you will hit the power limit on the discrete regulator.
  
 I would keep the voltage at the stock ±15V, the discrete regulator runs about 5-8˚C cooler with the Dexa, this means most of the power is going into the load. In order to maintain proper Class-A operation on the regulator it should be dissipating about half the maximum load power at idle.
  
 This is one of the downsides of using the Dexa.


----------



## Tomus4

b0bb said:


> The Dexa + Ticha will consume around 100mA, this borderline for power, if the voltage is increased too much you will hit the power limit on the discrete regulator.
> 
> I would keep the voltage at the stock ±15V, the discrete regulator runs about 5-8˚C cooler with the Dexa, this means most of the power is going into the load. In order to maintain proper Class-A operation on the regulator it should be dissipating about half the maximum load power at idle.
> 
> This is one of the downsides of using the Dexa.


 
 dexa - Supply current (Special Edition): typ. 20 mA per amplifier
 Ticha - max 38mA (Vcc=24V)
 So 120mA max when Vcc=24V When you set e.g. 20V will be less
  
 Are you sure the power limit on the discrete regulator is only 100mA? It has MJE15032 and MJE15033 transitors :
 Collector Current − Continuous IC 8.0 Adc
 Collector Current − Peak ICM 16 Adc
  
 I heard from my country Burson distributor which prefers V4 over V5 that V4 sounds better especialy when power supply is set 20V. And there is no problems with it. So mayby set Dexa + Ticha will play better with higher voltage.


----------



## justbenice

b0bb said:


> Keep it at ±15V or higher. Above ±18V you will need to keep an eye on the temperature, the optional heatsinks may be needed.


 
 Do you mean that the volt between pin 4-8 of the Ticha should be 15V ? But i trim all the bluepot near the heatsink it still show 25v


----------



## b0bb

justbenice said:


> Do you mean that the volt between pin 4-8 of the Ticha should be 15V ? But i trim all the bluepot near the heatsink it still show 25v


 

 Between pins 4 and 8 it would need to be 30V, 25V is too low to get good performance for the Ticha.


----------



## b0bb

tomus4 said:


> Are you sure the power limit on the discrete regulator is only 100mA? It has MJE15032 and MJE15033 transitors :
> Collector Current − Continuous IC 8.0 Adc
> Collector Current − Peak ICM 16 Adc


 
  
 100mA is per channel, total current consumption is 200mA
 The regulator is a Series-shunt type.
  
 For each rail:
 On the Shunt element dissipating half load current 15Vx0.1A = 1.5W dissipation
 On the Series element  assuming class A operation and near perfect transformer regulation (20V-15V)x0.2 = 1.0W
  
  
 The type of heatsink used by LKS has a thermal resistance of 10˚C/W with no airflow
 MJE15032 junction to ambient thermal resistance 62.5 ˚C/W and a case to ambient of 2.5˚C/W
 MJE15032 Max junction temp 150˚C
 In the worst case scenario of a 40˚C ambient, max power dissipated (150-40)/(62.5+2.5+10) = *1.47W*
  
 http://www.ti.com/lit/an/slva462/slva462.pdf
 https://www.onsemi.com/pub/Collateral/MJE15032-D.PDF
  
 I think you need to pay closer attention to the thermal limits of the device beyond just reading the max current capabilities from the datasheet.


----------



## justbenice

b0bb said:


> Between pins 4 and 8 it would need to be 30V, 25V is too low to get good performance for the Ticha.


 

  
 Thank you Bobb, It 30volt now. I trim up the 2 pot near heatsink, each pot up 2.5V to add up from 25v to 30v. Is it right?
  
 The volt between XLR 1-2 , 1-3, 2-3 now arround 1mv, is it ok ?
  
 I'v bouht a new dexa opamps and it will delivery in arround 2weeks, how do you compare the dexa opamps with the V5D (red one) ?
  
 Thank you !


----------



## Tomus4

b0bb said:


> 100mA is per channel, total current consumption is 200mA
> The regulator is a Series-shunt type.
> 
> For each rail:
> ...


 
 It means 2 times big heatsink will work?
 I have to study your explanation - it is not obvious to me


----------



## b0bb

tomus4 said:


> It means 2 times big heatsink will work?
> I have to study your explanation - it is not obvious to me


 

 Maybe, you need to look at the thermal resistance and the de-rate that number for use in a closed case with little or no air circulation.
  
 I used conservative figures in the first example which used the no heatsink thermal resistance numbers but in ambient air to approximate a closed case.
  
 Another way to look at this is to take it from the power dissipation perspective.
  
 Using the same formula in the TI document, for a 1.5W dissipation, the junction temp difference for a 10˚C/W heatsink in ambient air is (10+2.5) x 1.5 = 18.75˚C
  
 On a 40˚C ambient environment the junction temp in the transistor will be 40+18.75 = 58.75˚C
  
 Ambient thermal resistance figures quoted in datasheets assume convection air flow rate of 57linear ft/min blowing across the heatsink, the last page in the TI document has airflow tables from which an estimate in still air can be calculated, the multiplier is 1.25
  
 With the case closed the the junction temp would be 40 + (1.25x18.75) = 63.4˚C
  
 If you double the load current to 200mA, PD = 3W, the transistor junction would be at 37.5 + 40  = 77.5˚C with the case open, with the case closed it would be 86.9˚C
 This is getting quite high, running at the max junction temp of 150˚C, the max load current is about 470mA or 7W dissipation with the case closed.
  
 This is at best, still an estimate, estimating temperature rise in a closed or semi-enclosed box is complicated, below is an example
 http://www.heatsinkcalculator.com/blog/how-to-calculate-the-temperature-rise-in-a-sealed-enclosure/


----------



## Tomus4

b0bb said:


> Maybe, you need to look at the thermal resistance and the de-rate that number for use in a closed case with little or no air circulation.
> 
> I used conservative figures in the first example which used the no heatsink thermal resistance numbers but in ambient air to approximate a closed case.
> 
> ...


 
 Thank you very much for so detailed explanation. I left the electronics 20 years ago and have to refresh my knowledge.
 In the Internet are calculators like http://www.heatsinkcalculator.com/ what is nice this time. It is lot easier then 30 years ago to do memory refresh 
  
 I have info from Burson:
Hi Tomasz,
 
DC adjustment should not be needed regularly. 
 
In our own production and QC, we always tune DC towards zero when our amplifier or opamp is fresh off the production line.  Then after 100 to 200 hours of burn in depending on which product it is, we have to test and tune again. Once that is done, the product should last its lifetime without DC issues.
 
We have had customers using our V5 in their LSK DAC with great success.
 
Best regards,
 
Alex
 
 
 
    *Burson Audio*| www.BursonAudio.com | info@bursonaudio.com 
*Supreme Sound Audio*| www.SSAudio.com.au | opamp@bursonaudio.com
 Follow Burson on Facebook and Twitter!


 




       



 On Wed, Apr 19, 2017 at 4:14 PM,  





> Hi Alex.
> So now should be ok. A measured this voltage several times during last week and almost everytime I have DC below 10mV when music playing.
> Problem was with to big components tolerance. And this DAC's DC should be set up after every opa change. There is trimpot to do this. Probably I didn't care enough this previously and DC was to high.
> 
> ...


----------



## b0bb

justbenice said:


> Thank you Bobb, It 30volt now. I trim up the 2 pot near heatsink, each pot up 2.5V to add up from 25v to 30v. Is it right?
> 
> The volt between XLR 1-2 , 1-3, 2-3 now arround 1mv, is it ok ?
> 
> ...


 

 Keep both halves of the supply as close to +15V/-15V as possible, 1mV offset on the XLR is pretty good.
  
 DEXAs are little bit clearer than the V5Ds on the midrange, not much difference otherwise.


----------



## justbenice

tomus4 said:


> ....


 
  
  So did you manage to use the V5D ? Please let me know if it safe to use now. My XLR pin 1-2, 1-3, 2-3 now are arround 1mV only.


----------



## Tomus4

justbenice said:


> So did you manage to use the V5D ? Please let me know if it safe to use now. My XLR pin 1-2, 1-3, 2-3 now are arround 1mV only.


 
 It looks - yes. Please check this voltage when music playing and, how b0bb suggest, check power supply voltage between opa pin 4 and ground and 8 and ground. Shoud be less then 15V.


----------



## justbenice

tomus4 said:


> It looks - yes. Please check this voltage when music playing and, how b0bb suggest, check power supply voltage between opa pin 4 and ground and 8 and ground. Shoud be less then 15V.


 
 Thank you. I check those volt when music player it all around 1mV . But i tried all the way and could not trim the volt between pin 2-3  in left channel to 1mV, it is now 2.5mV . is it ok ?
 I also check the pin 4- GRD and 8-GRD, it all around 14.9V . 
  
 BTW, did you put your V5D to the DAC now ? How long it have been use ?


----------



## Tomus4

justbenice said:


> Thank you. I check those volt when music player it all around 1mV . But i tried all the way and could not trim the volt between pin 2-3  in left channel to 1mV, it is now 2.5mV . is it ok ?
> I also check the pin 4- GRD and 8-GRD, it all around 14.9V .
> 
> BTW, did you put your V5D to the DAC now ? How long it have been use ?


 
 left channel to 1mV, it is now 2.5mV . is it ok ? - it is because components (I/V resistors and caps) tolerance  - I had the same before components repacement - see previous posts
  
 Check please voltage on the RCA output. Before repacement I had 1,5mV in left channel- now I have 0,1mV.
  
 Power supply is optimal for V5
  
 Yes I put V5D today.


----------



## justbenice

tomus4 said:


> left channel to 1mV, it is now 2.5mV . is it ok ? - it is because components (I/V resistors and caps) tolerance  - I had the same before components repacement - see previous posts
> 
> Check please voltage on the RCA output. Before repacement I had 1,5mV in left channel- now I have 0,1mV.
> 
> ...


 
  My left RCA is 0.4mV , right RCA is 1.5mV. So is it safe to put the V5D in ? I already burned the V5D  one time so i don't want to burn it again   It may not get warranty this time !


----------



## Tomus4

justbenice said:


> My left RCA is 0.4mV , right RCA is 1.5mV. So is it safe to put the V5D in ? I already burned the V5D  one time so i don't want to burn it again   It may not get warranty this time !


 
 Ask Burson 
 I have 0,1 mV with default opa and 1,5mV with V5D. I ask Burson it is correct.


----------



## justbenice

tomus4 said:


> Ask Burson
> I have 0,1 mV with default opa and 1,5mV with V5D. I ask Burson it is correct.


 
 I am using the V5i, okay, i will email bruson


----------



## Tomus4

b0bb said:


> TX2575 take 7-10 days to settle in and the sound will smooth out by a small degree, it is not sensitive to temperature, one of the main reasons I chose it to avoid temp drift effects from the resistor self heating. The 9018 runs a fairly large current, so  effects of resistive heating needs some attention.
> 
> Pulsar is expensive at 400 Euros and is not available for sale in every country, contact Pulsar to verify.


 
 TX2575 take 7-10 days to settle in - 7-10 days 24h a day playing?
  
 Pulsar is expensive but worth the price, isn't it?


----------



## b0bb

tomus4 said:


> TX2575 take 7-10 days to settle in - 7-10 days 24h a day playing?
> 
> Pulsar is expensive but worth the price, isn't it?


 

 I just leave it powered on 24x7 10days in a row
  
 The Pulsar is worth it to me, you might want to try a less costly alternative first before getting the Pulsar.


----------



## Tomus4

Hi b0bb,
  
 The Pulsar has sent to me today. But I have a problem power supply for clock. I measued it today and I have 4,88V, so 1763 doesn't work. I don't know when it happend. Maybe Sanyo Oscon is damaged - I have to check it.
  
 I measured caps today:
 Sanyo OSCON  ESR- 0,09 VLOSS-2% over 54uF - new one - I have bought 2 extra.
 Nichicon              ESR- 0,34 VLOSS-1,1% over 47uF - desoldered from DAC
 Is it OK?
  
 Fortunately I orderd  http://www.ldovr.com/product-p/lt3045-s.htm together with http://www.ldovr.com/product-p/tps7a4700-lm31x.htm just to check it as power supply for oscilator. 
 Now it will replaced 1763. I would like to solder LT3045-S to caps leg  on the other side of the board.  Do you thing it is good idea?


----------



## Tomus4

b0bb said:


> 5)The Tekdevice board needs a 10uF tantalum capacitor soldered between  the IN pin on the regulator and ground, a suitable point is the bypass cap location, the one with the soldered jumper.
> I mounted the the 10uF cap on the other side of the board.
> 
> *NOTE: +ve electrode to the IN terminal and -ve to ground, do not connect the tantalum cap in reverse*
> ...


 
 I have http://pl.mouser.com/ProductDetail/KEMET/T350J156K035AT/?qs=sGAEpiMZZMtZ1n0r9vR22ZBQR9LXYg3mOZWE6B8GMKo%3d
 Will it be suitable ?
  
 As I understand mod around regulator http://www.ldovr.com/product-p/tps7a4700-lm31x.htm will be the same like Tekdevice


----------



## b0bb

tomus4 said:


> Hi b0bb,
> 
> The Pulsar has sent to me today. But I have a problem power supply for clock. I measued it today and I have 4,88V, so 1763 doesn't work. I don't know when it happend. Maybe Sanyo Oscon is damaged - I have to check it.


 
 You may have damaged a trace on the board while extracting the original caps, the OSCONS do not appear to be causing a problem.
 Check the ground and connections to R1 and R2 are intact.

  
  


tomus4 said:


> I would like to solder LT3045-S to caps leg  on the other side of the board.  Do you thing it is good idea?


 
 If the LT1763 regulator is broken, replace it with a new LT1763.
  
 The external regulator board is going to end up acting as a FM radio antenna. 100MHz is in the FM radio band.
 A FM radio signal is 100MHz±20kHz with the latter being the audio signal.
  
 In the XO world this frequency variation is called phase noise.
 Here is what happens to the Pulsar jitter performance when a 20uV FM radio signal with modulated 10Hz-10kHz audio white noise source is added in 100MHz±10kHz band
  

 Phase noise  (dB)Phase noise + 20uV FM modulated white noise (dB)10Hz-105-93.08100Hz-130-95.421kHz-140-95.5110kHz-148-95.54Jitter (fs)35.115 fs3769.48 fs
  
 This is one way to completely ruin the Pulsar's performance.
  
 I think this is a foolish waste of a 400€ OCXO.


----------



## b0bb

tomus4 said:


> I have http://pl.mouser.com/ProductDetail/KEMET/T350J156K035AT/?qs=sGAEpiMZZMtZ1n0r9vR22ZBQR9LXYg3mOZWE6B8GMKo%3d
> Will it be suitable ?


 
 Looks OK.


----------



## Tomus4

b0bb said:


> You may have damaged a trace on the board while extracting the original caps, the OSCONS do not appear to be causing a problem.
> Check the ground and connections to R1 and R2 are intact.
> 
> 
> .


 
 Regulator problem solved. There was no connection (cold solder) beetween R2 and board - Vout side. It looks like factory fault. 
 Thank you.
  
 I have question about Sony OSCON caps. Now I and you have 47uF and his legs are little bit under board - is it any problem for FM antenna effect?

 What about using bigger one e.x 150uF - legs should hide in the board.
  
  
 I will back with external regulator. I have an idea how to connect it to board to avoid antenna effect.


----------



## b0bb

A couple extra pictures of my 004.
  
*Front*

  
 The powersupply for the enhanced USB is new and quite different, more on that later.
 This one has the Jensen caps.
  
 The primary regulator for the DAC and XO is the LT1963

  
*Back of board:*

 Board is very clean, LKS did a great job of the post-assembly cleanup
  
*Closeup of I/V resistor*

  
 Looks like a high quality 0.5% tolerance resistor, this looks at least 0.75-1W to handle the large current.
 003 I/V resistor (249ohm) is 3.6x higher.


----------



## b0bb

Initial impressions out of the box is positive.
 Sound quality wise, it is better than the 003+CCHD950X in every aspect, it about ties with the Schiit Yggdrasil for imaging, instrument separation, sound staging and presentation.
 It has more bass slam and impact than the Yggy.
  
 Compared to the 003+Pulsar the 004 is a bit cold and flat especially on the midrange and the soundstage is somewhat smaller.
 The 004 falls apart on complex highly compressed tracks, instrument separation and imaging collapses which does not happen on the 003+Pulsar.
 The 004 beats the Pulsar combo on bass slam and weight of the low notes, very tight and very deep, not heard that from a DS DAC before, to me, flabby ill defined bass is the hallmark of almost all the DS DACS I have listened to.
  
 My unit has been burning in for about 2weeks.
  
  
 Sound underwent a lot of changes.
 On Day 1 almost all highly compressed pop and rock recordings sounded like the Chipmunks were doing the songs, thankfully this started to subside in the following days.


----------



## b0bb

A few more pictures on the new USB board power supply

  
 Opamp based discrete regulator

  
 Extra filtering on the output LC-Pi Network formed by the pair of 330uF Panasonic FMs and inductor.
 Previous only has a Pi filter on the  DC input side, new one adds the output filter in addition.


----------



## b0bb

LKS 004 runs very warm, below are temps in 2 critical areas, measurement done using a thermocouple with the case closed
  
 Center of DAC chip. 72.3 degC

  
 Output transistor on discrete I/V. 58.5 degC


----------



## b0bb

Mod to add heat shield tape to the Nichicon FGs.
 At nearly 60ºC, the FGs will cook in a matter of months, this buys some time for the DAC to settle in and I will replace these with something more robust.
 (Cap lifetime calculation estimates this at 7 months @59ºC)
  
 Poor layout of the parts  by LKS, the caps are boxed in leaving no space for airflow. I am going to move the blue caps to the underside to free up more space for the air channel.
 Heatspreader on the transistors pointed directly at the caps makes the problem worse.
  

  
 Shield on the FGs  from various angles.


----------



## b0bb

The USB input is galvanically isolated from the DAC, unfortunately the metal parts of the USB socket touched the metal front panel, this bypasses the isolator.
  
 This mod corrects it by adding several layers of Kapton insulating tape on the USB connector.
  

  
 Kapton insulaton around USB connector.


----------



## b0bb

Simple mod that twists the AC wiring pairs to reduce the EM field.


----------



## Tomus4

b0bb said:


> Initial impressions out of the box is positive.
> Sound quality wise, it is better than the 003+CCHD950X in every aspect, it about ties with the Schiit Yggdrasil for imaging, instrument separation, sound staging and presentation.
> It has more bass slam and impact than the Yggy.
> 
> ...


 
 003+CCHD950X -does it mean fully modded 003+ CCHD950X ?


----------



## b0bb

tomus4 said:


> 003+CCHD950X -does it mean fully modded 003+ CCHD950X ?


 

 Yes.


----------



## b0bb

Below is a more specific lifetime estimate of the Fine Gold caps.
  
 The calculator is from Nichicon. http://www.nichicon.co.jp/english/products/lifetime/dc.html?sr=UFG
  
 This apply to the caps directly next to the 004's output transistors running at 59ºC


  

  
  
  
The caps are expected to last *7months* if the LKS 004 is left powered on 24x7


----------



## Tomus4

b0bb said:


> Yes.


 
 When 004 + Pulsar test?


----------



## b0bb

tomus4 said:


> When 004 + Pulsar test?


 

 In my list of TODOs but only after the DAC settles in and the numerous thermal and related issues with this DAC are understood and addressed.


----------



## justbenice (Apr 27, 2017)

In the last few weeks i heared alot of good things about R2R DAC, especial a Holo Spring DAC. I was very intersting in Holo Level2 DAC and  thought gonna buy one to replace my LKS Dual ES9018 DAC and i am very lucky that my friend have one Holo Level2 and yesterday he bring it to my house to let me compare between the LKS Dual ES9018 and Holo Level2 :





 Gear :
 +  Amplifier : Accuphase E600 classA
 + Speaker : Tannoy Turnberry GR
 1. Holo level2 + Singxer SU1 (I power on it 3 hours before testing)
 2. LKS Dual ES9018 MH-D003 with modded USB board.

 Result :

 After a few hours testing and listening 2 DAC, i decide to keep my ES9018 DAC ) 
Yes, i was very impressing with the Holo level2 when first time hearing it. It have very very softly and sweet mid tone. Especial the voice of singer was very thick when compare to the ES9018. And it sound more analog, more "cd" than the ES9018.

But after all i will keep the ES9018 and gave up the idea that buying Holo Level2 because the holo level2 have less details than the ES9018 alot. Holo level2 also lost a very-high range and mid-high range,  so the sound could not "open" like the ES9018. 

Holo Level2 is great DAC but i like the ES9018 more because my type of music.


----------



## moss

Hi b0bb,

I just got a MH DA-004 and am enjoying it very much.  Thank you for the modding tips.  What is the heat shield tape that you are using?

Thanks.


----------



## b0bb

moss said:


> Hi b0bb,
> 
> I just got a MH DA-004 and am enjoying it very much.  Thank you for the modding tips.  What is the heat shield tape that you are using?
> 
> Thanks.



DEI 010391
https://www.designengineering.com/c...gineering-inc/heat-sound-barrier/reflect-gold


----------



## b0bb

justbenice said:


> After a few hours testing and listening 2 DAC, i decide to keep my ES9018 DAC )
> Yes, i was very impressing with the Holo level2 when first time hearing it. It have very very softly and sweet mid tone. Especial the voice of singer was very thick when compare to the ES9018. And it sound more analog, more "cd" than the ES9018.



Adding the Corning CGW caps in parallel with the opamp bypass (Panasonic FM)  caps will bring out the midrange fullness. Use a value of 100-220pF, either the CY or TY series will work.


----------



## justbenice

b0bb said:


> Adding the Corning CGW caps in parallel with the opamp bypass (Panasonic FM)  caps will bring out the midrange fullness. Use a value of 100-220pF, either the CY or TY series will work.


Did you do that to your DAC ? if you do, please take a picture so i can do it easier ! 
Great thanks !


----------



## justbenice

About using Burson V5D opamps in LKS DAC. Here are the answer from Burson :




 
So i am safe to use the V5D now. 
Thank you Burson.


----------



## b0bb

justbenice said:


> Did you do that to your DAC ? if you do, please take a picture so i can do it easier !
> Great thanks !



CGW caps marked, you can leave the existing cap in place and just solder the CGWs to the underside


----------



## justbenice

Thank you boob. I will do it


----------



## fjc36

b0bb said:


> Initial impressions out of the box is positive.
> Sound quality wise, it is better than the 003+CCHD950X in every aspect, it about ties with the Schiit Yggdrasil for imaging, instrument separation, sound staging and presentation.
> It has more bass slam and impact than the Yggy.
> 
> ...


----------



## fjc36

B0bb, Are you purchasing or borrow a da 004 with 9038pro twin inside and start  studying and investigating? I want to be sure, it is a bit sudden.


----------



## fjc36

b0bb said:


> Initial impressions out of the box is positive.
> Sound quality wise, it is better than the 003+CCHD950X in every aspect, it about ties with the Schiit Yggdrasil for imaging, instrument separation, sound staging and presentation.
> It has more bass slam and impact than the Yggy.
> 
> ...


----------



## fjc36

The 004 falls apart on complex highly compressed tracks, instrument separation and imaging collapses which does not happen on the 003+Pulsar.

What can we do about? Also, the very unusual high temperature worries me about the performance, damage and life in long time.


----------



## fjc36

Peoples are turning head to another Chinese made DAC-the matrix audio x sabre pro. And I start wondering how many of ESS 9038pro and MFG's support are released to the market?


----------



## moss

Thank you b0bb


----------



## penguin69

I'm away for a couple of weeks, I come back and find that b0bb has got himself a 004 - awesome! And the tweaks have started!

My 004 listening is somewhat starting anew as I've just changed out my power amps (Cyrus x300 sigs  --> Quad II 80's).


----------



## justbenice

I am staying with my MH-DA003. And i dont believe the new DA004 can have  better sound than my "modded" DA003. 

Unless the new 9038pro DAC that fix the heat isssue in the DA004 orthewise there are no chance i choice the DA004


----------



## Ric Schultz

b0bb,
How many degrees did the temperature of the caps lower when you installed the heat shields?

Another thing to try would be to put a piece of copper foil tape (still with paper backing on it....to keep it stiff) between the transistors and caps.  This would absorb the heat but because it has the paper on the back, it would not radiate into the caps.  It could be mounted so it would not touch the transistors.

You could also use several layers thick conductive glue copper foil and mount them directly on the transistors to act as heatsinks.....if you made them tall enough....the heat would go up and not back much.

I will try both methods and see what reduces the heat the most.  Like the copper foil shield method best as it is easy and fast.

Wrapping the caps with the heat shield material WILL change the sound.  Better? Worse?  They sound great now.....don't personally like this option.


----------



## b0bb (Apr 30, 2017)

Ric Schultz said:


> b0bb,
> How many degrees did the temperature of the caps lower when you installed the heat shields?



About 4ºC

This extends the life of the caps by 50% (0.6yr ⇒ 0.9yr)
Using Nichicon's calculator for the Fine Gold (UFG) 85ºC/1000hr

 Temp (ºC)Lifetime in years590.6550.9501.2451.8402.5
Nichicon make the KA (UKA) audio cap 105ºC/2000hr

 Temp (ºC)Lifetime in years595.5557.35010.34514.64015
Extensive heat sinking will bring down operating temps to the range of 45-50ºC, the 2yr lifetime of the Fine Golds make this hardly worthwhile in my view.

However with the KAs there is substantial gain in the usable lifetime.


Ric Schultz said:


> Wrapping the caps with the heat shield material WILL change the sound.



This is to be expected.  The thermal shields did not degrade the sound, there was less breakup on highly compressed tracks and the very low bass notes gained a small increase in the heft and impact.

I put it down to a reduction in thermal stress.

Degradation from the heat will eventually catch up and ruin the cap, the heatshield buys time until a better solution is found.

(PS this new interface is terrible, where did the table editor go?)


----------



## b0bb (May 2, 2017)

Heatsinks  on the I/V output transistors, this is an experiment to see if heatsinks reduce the ambient temps around the caps.









Ambient temp dropped to 51ºC, this is a substantial change from the 59ºC in the unmodified stock case.





Location of the thermocouple






The current choice of heatsink is a 21ºC/W unit, larger heatsinks won't fit due to the space constraints.
This current arrangement show that there is much to be gained by adding heatsinks to the output transistors.
The heatsink temp was about 60ºC, not bad considering it is connected to 2 transistors, the vent area above the transistors feels noticeably warmer, so the heatsinks are dissipating the heat as expected. More importantly  it is preventing the heat from radiating into the nearby caps.

I took the opportunity  to thermally couple the 2 halves of the output pair, this stabilizes the DC operating point of the opamp and reduces the DC drift.
Somewhat unexpected was an improvement in sound quality, the soundstage got much deeper and wider, did not expect this as the 004s soundstage is already very good.


----------



## penguin69

b0bb, a $0.30 mod. Genius!

http://www.surplus-electronics-sales.com/index.php?main_page=product_info&products_id=1131


----------



## Ric Schultz

b0bb,
Very cool....well, at least cooler.  Is that Kapton tape underneath the heatsinks to keep the transistors from being shorted?


----------



## b0bb

Ric Schultz said:


> Is that Kapton tape underneath the heatsinks to keep the transistors from being shorted?



Yes


----------



## vick_v

I have been looking into the MH-DA004 and noticed that the XLR output frequency response is listed as 20Hz-20kHz and many of the competing DACs list at least 50kHz limit. The top hit (on google) that sells the DAC confirmed the above.
Is there anything that can be done to up that limit to at least match my bookshelf speakers at 40 kHz.  Or is it possible that the info is incorrect?
I know we can't hear that high of a frequency but I am looking to build a system capable of reproducing this range and find out for myself if it makes any difference.


----------



## RickyV

Hi bobb,
I am a F1 user and looking to upgrade the cchd-575-25 clocks to something better. Do you know of a better clock that will fit the pcb lands? 
Also i had an idea to replace the clocks LDO (adp 151) with a pulsar power, very short leeds 1cm or so.


----------



## b0bb (May 4, 2017)

RickyV said:


> Hi bobb,
> I am a F1 user and looking to upgrade the cchd-575-25 clocks to something better. Do you know of a better clock that will fit the pcb lands?
> Also i had an idea to replace the clocks LDO (adp 151) with a pulsar power, very short leeds 1cm or so.



NDK makes an alternative.
http://www.diyinhk.com/shop/audio-kits/35-ndk-nz2520sd-20ppm-ultra-low-phase-noise-oscillator.html

Phase noise is lower "on paper", I have not used it in the F1, and it remains to be seen if it can do a better job than the Crystek.

The performance of the F1 is limited by the capability of the DAC's SPDIF receiver, the crystal in the F1 merely has to be good enough to get the job done and the 575 is more than adequate.

You should post on the other threads dedicated to the Singxer to get a better sense of what works.


----------



## RickyV

Thanks bobb,
Yes sorry about that. I read this intresting threat yesterday and you were the perfict man for the question i had.

Happy modifing.


----------



## dacusb

b0bb said:


> Adding the Corning CGW caps in parallel with the opamp bypass (Panasonic FM)  caps will bring out the midrange fullness. Use a value of 100-220pF, either the CY or TY series will work.



Hi b0bb,

Where can I get the said Corning CGW caps?
Thanking you very much.


----------



## dacusb

b0bb said:


> Next installment of my LKS MH-DA-003 mods
> 
> High voltage Schottky rectifiers, these devices are fast recovery, compared to conventional diodes these use the majority carrier conduction mechanism.
> 
> ...




Hi b0bb,

Schottky rectifier diodes 100V 10A from Vishay part number MBRF10H100-E3/45 are out of stock at both Mouser and Digikey. Can you provide us with other sites where we can get them?
Thanking you very much.


----------



## b0bb

dacusb said:


> Hi b0bb,
> 
> Schottky rectifier diodes 100V 10A from Vishay part number MBRF10H100-E3/45 are out of stock at both Mouser and Digikey. Can you provide us with other sites where we can get them?
> Thanking you very much.


RS Components or Farnell might stock these, check with them to see if they can help you


----------



## justbenice

For the last few days i tried the Dexa New ClassD opamps and found out it sound very accurate. The Burson V5D have sweeter sound but i like the Dexa more.


----------



## Ric Schultz (May 13, 2017)

RE the new 004: I measured the temperature of the IV output transistors and directly on top of the Nichicon caps after an hour with the top off.  The temps were 45 for the transistors and 43 for the caps.......way, way less than what b0bb measured with the cover on.  I find that most gear sounds best with the cover off.....That is how I have all my gear.  So, better sound and longer lasting caps without any mods.  Just remove the cover.  Helps if your DAC is out in air like mine ......if inside a small shelf then it will get hotter.  Put it on top of your rack and with no cover and you are good to go......just don't spill any drinks in it.....he he.   Just dust it out once ever six months....unplugged, of course.

A friend with the 004 tried the heatsinks on the transistors and reported closed down bad sound.  I have the heatsinks and will try them sometime next week.  I will report what I hear.


----------



## penguin69

I ran my 003 with the lid off also. Not so aesthetically pleasing to all, but a good way to keep temps down!


----------



## b0bb

The heatsinks are just an experiment to see if it can bring the temps down with the case closed, in reality they are far too small for a proper cooling job.
The temp reduction was better than expected so I will spend the time to rebuild the output stages for better cooling.

This is not a permanent mod and it requires a lot of adjustment and I did not add any links for the materials I used as a result.

Unless extreme care is taken, the temps in the center pairs can be as much as 10ºC higher than the ones on the sides due to the small size of the heatsinks.
I had to adjust the clamping force on mine a few times to get it to behave.
There should be less than 2ºC difference between the center of the transistor mounting hole and the top of the heatsink, if not the mounting is off.

The temps on both halves of the output stage transistor pairs have to be within 2-3ºC otherwise the gains on both halves of the differential output will be mismatched leading to changes in the sound.
Given the LKS layout, the inverting output runs hotter than the non inverting input on the left channel with the reverse effect the right channel, leading to truly weird effects.


----------



## mb3 (May 13, 2017)

b0bb said:


> The heatsinks are just an experiment to see if it can bring the temps down with the case closed, in reality they are far too small for a proper cooling job.
> The temp reduction was better than expected so I will spend the time to rebuild the output stages for better cooling.
> 
> This is not a permanent mod and it requires a lot of adjustment and I did not add any links for the materials I used as a result.
> ...


I found this mod worked well for me - placing one heatsink across two transistors. The unit is now significantly cooler. see https://www.jaycar.com.au/to-220-clip-on-heatsink-6043-type/p/HH8503


----------



## mb3

Info about the ess9038pro chip filter settings.


----------



## b0bb

mb3 said:


> I found this mod worked well for me - placing one heatsink across two transistors. The unit is now significantly cooler. see https://www.jaycar.com.au/to-220-clip-on-heatsink-6043-type/p/HH8503


That looks good a bit more metal than the one I used.


----------



## mb3

yes they were pretty good - and also insulated so no problem with shorting


----------



## vick_v

mb3 said:


> yes they were pretty good - and also insulated so no problem with shorting


What did you do with the snap-on ridges on the flat side? It looks like those would greatly reduce the contact surface.


----------



## mb3

vick_v said:


> What did you do with the snap-on ridges on the flat side? It looks like those would greatly reduce the contact surface.


I just used a flat head screw driver and fine pliers to flatten out the ridges - I then put a little kapton tape to cover that side of the heat sink.


----------



## mb3 (May 15, 2017)

I recently purchased the lks 004 amanero usb version. This is a very brief summary of my experience with setup, which I hope would be helpful to those interested.

It's pretty good to have the first dual ess9038pro chip dac. Sound quality is excellent, no doubt.

Setup took a little research and time.

For playback from PC by usb, driver install is needed - amanero 1059 for win10, then pc audio output selected as amanero usb. If this is not done correctly, then I get no sound at all.

For playback - foobar.

DAC filter setting, info shown above - usually set to minimum phase fast roll-off.

For DPLL settings - I've been unable to obtain specific info from either ESS or LKS about what the DPLL setting equals for the ess9038pro chip, and as it follows, for the LKS 004. From my limited experience, as expected, DPLL 1 provides the best sound quality by far.

For PCM and DXD file playback - I've had no problem using DPLL 1 for all file types and sample rates (LKS shows PCM). Playback of all PCM and DXD files and also DSD to PCM (set in foobar) was perfect, no matter what, with DPLL 1 setting. 

Note the following discussion only relates to DSD file playback. For DSD files played back in native format (LKS shows DSD), DSD64 files with DPLL 2-5 setting is usually pretty good. For DSD128 or DSD256 results vary - some files play stably at DPLL 3. Others have 'static' even at DPLL 15.

Playback of DSD files seems extremely sensitive to a variety of poorly defined factors. From my experience this static issue for native DSD file playback is a real issue. Maybe this is why so few DACs offer this feature, or limit playback to DSD64. To clarify - by static I mean anything from, the snare drum in the left speaker sounds distorted (but sounded clear on the PCM file) to hearing white noise only.

Causes for dsd file playback issues can be summarized along these lines,
1. Power supply factors - to the lks itself. Due to the household wiring, eg. brought on opening the refrigerator door, using the washing machine, etc. Unfortunately, I found that using a line/surge protector to power the lks actually increased the chance of static noise during DSD playback.

2. Computer and usb related noise - there are many guides about optimizing a computer for audio playback, I found that making a few changes was worthwhile, see the yt video below as an example of how to do this. In general it seems that using the computer for anything other than music playback can be detrimental. There are various reports about disabling computer features, eg. i7 turbo mode, and generally disabling computer functions until windows barely works properly - I'm not sure if taking things to this level helps. Maybe using a laptop powered by battery, or using a sotm or antipodes device would give better results. I did find that using a usb 'decrapifier' probably reduces the occurrence of static.

3. Software factors - there are a variety of programs available for audio playback, so probably there is no 'best' option. I found foobar was best for me. In terms the setup that allowed dsd files to play - after trying several different configurations... I found best results using foobar set to ASIO playback, using ASIOProxyInstall-0.9.4, and foo_input_sacd-0.8.4 (links below). This allowed bit perfect DSD file playback for all file types and sample rates. 

Then the following changes to foobar probably made a minor improvement in sound quality. I set ASIO output with around 10000ms buffer, then set to no replay gain, use 64 bit drivers, playback with priority, and use full file buffering from memory. Use a 40kHZ filter to limit artifact noise intrinsic to dsd files - which could in theory damage equipment.

4. Problems with the music introduced during the recording / processing +/- upsampling process seem amplified in DSD files.
Files recorded in PCM and up-sampled to DSD seem to have a higher rate of static, as expected.

5. Issues with the design of the device - eg. temperature, dual chip sync, dpll setting, power supply isolation, not allowing the usb input to touch the case. Ensuring optimal component temperature seems important. There are reports recommending both increasing  and decreasing device temperature being helpful - allowing the device to warm up vs. keeping the device cool by using heat sinks on the transistors or keeping the lid off. Who would know? No way to be sure with the first device of its type.

Having tried to address several factors to improve dsd file playback, I'm not too sure it matters anyway. At the end of the day, I've found that native PCM and DXD file playback is outstanding, and setting DSD files to playback in PCM format will provide excellent results.

Further info:
Latest amanero drivers; https://amanero.com/drivers/
ASIO proxy - I found this was needed; https://sourceforge.net/projects/sacddecoder/files/foo_dsd_asio/
Foobar asio output support; http://www.foobar2000.org/components/view/foo_out_asio
Foobar sacd component; https://sourceforge.net/projects/sacddecoder/files/foo_input_sacd/
Computer setup example; search 'how to optimize Windows 10 anniversary update'


----------



## justbenice

I have a oppo 205 and it ES9038PRO DAC chip is not too hot. So  may be there are something wrong with the LKS 004 ?


----------



## mb3

Cheers, good to know - board design would be a factor. Transistor heat sinks solved this issue for me.  Out of interest - how does the oppo handle setting dpll and also native dsd file playback back?


----------



## abartels

Hi b0bb,

Ever tried ultracaps? Maybe take a look at this thread, it's very interesting.
https://www.head-fi.org/f/threads/r2r-da-m1-ultracap-powered-build.839007/page-4#post-13466545

I have a Kali reclocker powered with ultracaps, and my AK4495 now also has all it's voltagerails (6x) powered by ultracaps.

Those psu's are LDO-free design, just needs careful calculation of runtime ultracaps to stay between voltage tresholds.
This gives us a pure DC supply which in my opinion outperforms EVERY conventional psu design.

These designs have lots of relay switching (for my dac 26 relays each ten minutes), but switching noise can be kept to a minimum within enclosure with little damping.

Since loading circuit is galvanic isolated from running circuit, there's no need to take care of clean power to feed and charge the modules, a laptop adapter is all you need.

Soundwise, how do those ultracaps perform? You have to listen to them to believe it. It just combines the best of the best of both worlds (analog & digital).

Since I first started to use them in psu for my Kali reclocker, I allready was convinced I wouldn't go back to LT3042 with R-Core and EMI/RFI filtering.
Since powering my whole dac, eh, networkstreamer it should be called, with ultracaps, I never COULD go back to conventional linear psu's, that's for sure.

Sad thing is, if I wanted to power my pre-amp with ultracaps in an audiophile manner, I would need at least 96 BIG ultracaps (350F Maxwell - D-Cell format), which would result
in  an external enclosure of 430mmx120mmx410mm (lxhxd). But I am really thinking on building this in the future.


Just give it a try b0bb, you will be VERY pleased, promised 

Cheers,
Alex


----------



## penguin69

Hi b0bb (and others)

Any further modding to the 004 to report?

I have been out of the loop for a good while due to bad health, but I hope to get a soldering iron back in my hand in the next couple of months.

pat


----------



## fjc36

Have anyone compare to or own a OPPO Sonic DAC?


----------



## b0bb (Jun 7, 2017)

penguin140369 said:


> Hi b0bb (and others)
> 
> Any further modding to the 004 to report?
> 
> ...



The stock 004 is quite good, SQ wise several notches above the 003, even my modded one, it has caused a degree of complacency

I am almost done with house remodelling which has been taking almost all of my freetime. This is almost done so I will have time later in the year to add the OCXO

One of the things I added in the remodel are new dimmers for LED lighting which use reverse phase dimming aka IGBT dimmers.
Until LED lamps showed up, these were in the 4 figure price range used in stage and theater lighting.

These put out a lot less RFI compared to the older SCR or Triac dimmers,and therefore less RFI junk in the house wiring.

The 004 SQ went up by half a notch which was unexpected.

The 004 seems very sensitive to RFI, I already have 2 RFI filters in line going to the DAC in addition to the RFI filter on the old Triac dimmer.


----------



## b0bb (Jun 7, 2017)

abartels said:


> Hi b0bb,
> 
> Ever tried ultracaps? Maybe take a look at this thread, it's very interesting.
> https://www.head-fi.org/f/threads/r2r-da-m1-ultracap-powered-build.839007/page-4#post-13466545
> ...



Been looking off and on at the thread mentioned,  the LKS 004 consumes far too much power to make an ultracap PSU a practical reality.
I have another DAC (JOB/Goldmund DA96) which uses about 5W that is a candidate for the ultracap PSU.

However I find the dependence on relays clunky and affects overall reliability.
When DC is switched, the arc causes oxide to build up on the switch contacts.
On the other thread, you reported the contact resistance building up on some of the relays you tried.

Waiting to see if someone puts out a decent charge controller and voltage regulator for these caps.
A LDO could be modified to work for this purpose if it supports constant current output.

I think in the next 12-24 months we will be seeing much more refined ultracap PSUs hitting the market, hopefully without the relays.


----------



## mb3

b0bb said:


> The stock 004 is quite good, SQ wise several notches above the 003, even my modded one, it has caused a degree of complacency
> 
> I am almost done with house remodelling which has been taking almost all of my freetime. This is almost done so I will have time later in the year to add the OCXO
> 
> ...




Just checking if you could be so kind as to let us know which RFI filter you are using? This one looked ok to me. http://www.poweronaustralia.com.au/product/eaton-psfi/

Thank you


----------



## abartels (Jun 15, 2017)

@b0bb,

I can understand your concerns about relay reliability, but you know as I know that there are very reliable relays which can do the job perfectly, like the Takamisawa NA12W-K or others.
The gold contacts really do not oxidate that much as you mentioned, and, they are bifurcated, and, those are DPDT, so you can parallel those and reduce resistance to 25 mOhms.

Those Chinese relays, used at the boards I bought, are far from reliable, and this isn't related to relay reliability in common, they just are very cheapo and crappy.....

To prevent oxidation within relays, they often use a so called "WET circuit", which simply is a bypass film cap across switching contacts, in this case 100nF to 1uF should do the trick.

Quote from http://control.com/thread/963420679 :

"> What is Oxidation of relay contacts and what can be done to prevent it ??

For both relay and metallic switch contacts for low current level (e.g. logic) You have two choices.

1) use Au plated contacts

2) Use a film capacitor which has low ESR to "wet" the contacts. Unless the contact is specifically designed for dry contact switching (eg telephony sealed switches) you MUST use a cap to make it a "WET" circuit. This means the current during switching is high enough to burn through a partial oxidation layer to lower the contact resistance ESR using the low ESR and stored charge of a capacitor to dump the current across the contacts. The capacitor must be close to the switch. Suitable values of Film caps start at 10nF and for say 30Amp relays use 10uF tantalum or low ESR alum. This will keep the contacts clean when used enough. Normally current must be 10% of rated current to prevent oxidation. Although the transient from a low ESR cap will be much higher than this, the duration will be so short that there is not thermal rise except at the surface oxidation layer enough to burn off the ofxide.

Tony Stewart EE '75 (retired PEng)"



When looking at the Takamisawa specs, Electrical lifespan is about 500.000 operations at 1A-30VDC
It's mechanical lifespan is about 100.000.000 operations.

In my case, switching every 10 minutes, relays should exactly last as much as long as the 100F ultracaps which, if used 24/7, would last for 18 years of continuous playing.........

For my new design I will use those Takamisawa's, and put them in simple DIP-14 IC-sockets, which is very handy to replace a relay in case of troubles.

There are some people who are designing charge controllers, which just makes it easier to use (no runtime calcultaion because of voltage sensing), but still would need relays, mechanical or SolidState, or mosfets to switch.
You know as much as I know, voltage drop of SSR's or mosfets ruins ESR of ultracaps, which makes all those upcoming "better" designs worse sounding.
And, using voltage regulators also ruins the perfect audio characteristics of those ultracaps.

I can understand if you wanted to use utracap psu's for your LKS, it wouldn't be a practical design, but, since we are no commercial guys, and want the best of the best available SQ,
this should be of some interest to you.

Just try to power a simple USB-I2S interface with ultracaps, I am very sure you'll get interested................


Cheers,
Alex


----------



## vick_v

I would like to install a 12V trigger in in the MH-DA004. Any ideas on where to start?
I was thinking that worst case I can reverse engineer the signal sent from the controller to the board via that ribbon cable and tap into that but if someone can spot an easier method that would be great!
Or maybe someone has an idea what protocol and pin-out that controller is using?


----------



## b0bb

mb3 said:


> Just checking if you could be so kind as to let us know which RFI filter you are using? This one looked ok to me. http://www.poweronaustralia.com.au/product/eaton-psfi/
> 
> Thank you



I use isolation transformer + tracking filter.
https://powervar.com/standard-power-conditioners/
http://www.digitaltele.com/pdf/emerson/islatrol_lric_ic_plus.pdf


----------



## b0bb (Jun 16, 2017)

abartels said:


> @b0bb,
> 
> I can understand your concerns about relay reliability, but you know as I know that there are very reliable relays which can do the job perfectly, like the Takamisawa NA12W-K or others.
> The gold contacts really do not oxidate that much as you mentioned, and, they are bifurcated, and, those are DPDT, so you can parallel those and reduce resistance to 25 mOhms.
> ...



The USB-I2S interfaces I use needs about 10W, so the relays will need to switch at least 3A@3.3V, the Takamisawa is not rated for this.

Gold has a low boiling point and will evaporate in the arc instead of oxidizing, I would use relays with Palladium or Indium alloys in the contacts minus the gold plating.The Takamisawa is using a Silver-Palladium alloy under the plating.

Gold plated relays like this one should only be used for switching low level circuits like DAC audio outputs.

TE makes a lot of relays and they have a good write up on relay contact materials, at the end of the article is some info on how to calculate the snubber network, aka the  "wet" part.
I see this as a complication when using relays. 
http://www.te.com/commerce/Document...v&DocNm=13C3236_AppNote&DocType=CS&DocLang=EN

I see designs using SSRs and I would not use these designs.

MOSFETS switches are another matter, for example the SSM6J0503N from Toshiba has an on resistance of 32.4 mOhm @ 3A, 4.5V 
This is about 2/3 the contact resistance of the Takamisawa (50mOhm) and it carries a higher current without the contact wear concerns. Digikey sells them.

https://www.digikey.com/product-det...e/SSM6J503NU,LF(T/SSM6J503NULF(TCT-ND/3522397

The link below show the kinds of features I am interested in, namely microprocessor controlled transistor bank switching and an integrated charging circuit.
https://uptoneaudio.com/products/ultracap-lps-1

Just waiting for the rest of the industry to catch up.


----------



## b0bb

vick_v said:


> I would like to install a 12V trigger in in the MH-DA004. Any ideas on where to start?
> I was thinking that worst case I can reverse engineer the signal sent from the controller to the board via that ribbon cable and tap into that but if someone can spot an easier method that would be great!
> Or maybe someone has an idea what protocol and pin-out that controller is using?



An external current sensing power strip is the easiest, use a 12V wall wart on the controlled outlets for the trigger.

BITS makes one with an adjustable current threshold
https://www.bitsltd.net/products/Details.aspx?p=1864396&sc=78&sg=all

If you want to trigger from standby mode, you will need to check and see if there is a difference in the current consumption between on and standby modes.


----------



## vick_v

b0bb said:


> An external current sensing power strip is the easiest, use a 12V wall wart on the controlled outlets for the trigger.
> 
> BITS makes one with an adjustable current threshold
> https://www.bitsltd.net/products/Details.aspx?p=1864396&sc=78&sg=all
> ...



Thanks, but I want my pre-amp to trigger the DAC to turn on and I think what you describe would do the other way around. My pre-amp already has a 12V trigger out.
I really don't want to keep the DAC on all the time and would prefer if it was on standby in order to reduce the heat and prolong the life of the parts. Is turning the DAC on and off instead of using standby worse, better or the same?


----------



## jcn3 (Jun 18, 2017)

vick_v said:


> I really don't want to keep the DAC on all the time and would prefer if it was on standby in order to reduce the heat and prolong the life of the parts. Is turning the DAC on and off instead of using standby worse, better or the same?


Assuming the dac was designed by a competent engineer, leaving a dac on all of the time does not reduce its life expectancy. This belief is a holdover from decades ago when tubes (including picture tubes) were common. Putting it in standby mode will only save you a few dollars a year.


----------



## penguin69

b0bb said:


> The stock 004 is quite good, SQ wise several notches above the 003, even my modded one, it has caused a degree of complacency



Yes, I must admit that the stock goodness of the 004 has me in complacency mode to an extent also.


----------



## penguin69

Three questions to the floor:

1) Would a USB interface such as the following provide an improvement over the Amanero board?

https://www.shenzhenaudio.com/singx...nterface-with-xmos-xu208-cpld-dsd256-dop.html

I ask as I have always been interested in trying an I2S interface, and the asking price for the above unit is not astronomical.


2) Due to an issue with the US->UK power converter for my Adcom GFP-750 pre-amp, I am currently using the 004 in 'preamp mode', i.e. using the digital volume control with the unit connected directly into my power amps. When I can afford it, I will probably put a Schiit Freya inline, to replace the Adcom. However, I am wondering at what point the quantization noise degradation of a digital volume control becomes unnoticeable. FWIW, I typically listen to my 004 with the level set at around -49 to -55db. It's probably a very subjective question, but at what point does an inline passive pre-amp make more sense than the native digital volume control? My small brain says "go for the resistor and 0db" but is that really going to give better results than a digital volume control with no other component inline?


3) Has anyone compared the balanced to the unbalanced outputs? I've used both options direct into my power amps, and I seem to find myself preferring the unbalanced connection - which surprises me somewhat.


----------



## b0bb (Jun 22, 2017)

penguin140369 said:


> Three questions to the floor:
> 
> 1) Would a USB interface such as the following provide an improvement over the Amanero board?
> 
> ...


LKS configured the 9038 to re-clock all incoming streams, the custom re-clock logic that you will be paying for on the SU-1 largely goes to waste.
The cost is within 50USD of the Pulsar OCXO, this replaces the XO in the DAC at the the very centre of the 9038's re-clock logic, I think that mod has better value for the money.

LKS paid little attention to the I2S interfaces, most of the logic is powered by the slow and somewhat noisy LM317, the LM317 is a huge step backward from the LT317 used on the 003.
Take a look at how PSAudio implemented I2S and compare to see how I2S is poorly done on the LKS.

I do not see any major changes in the I2S section between the 003 and 004 and expect the same kinds of problems with the SU-1, namely clicks and sometimes loud bangs when switching sample rates or mode changing between PCM and DSD.

Link below describes how the SU-1 does not play nicely with the LKS 003.
https://www.head-fi.org/f/threads/lks-audio-mh-da003.745032/page-25#post-12927931

The very same seller in your link blamed the LKS and walked away leaving the customer high and dry.
Suggest you check to see if the seller eventually made it right for the customer.

LKS utterly messed up the enhanced USB interface implementation on the 004.

The USB thing is powered by a secondary winding off the digital transformer, creating a direct path for digital noise from the host + the USB board right into to the DAC. Toroids have very wide bandwidth giving the noise a very low impedance path coupled through the secondary windings, this bypassed the interwinding screen on the transformer rendering it useless.
LKS did not insulate the USB input from the rest of the DAC metal work, this joined the ground on the host and the DAC completely bypassing the galvanic  noise isolator.

This amateurish blunder robbed the 004 of a large chunk of its potential.

The fix is simple, power the USB board with its separate transformer with an interwinding screen between the primary and secondary windings and most importantly insulate the USB input from the rest of the metalwork.

The SQ difference after this change is not subtle.
Improvement on a level similar to the step up in SQ between the 003 and the stock 004



> 3) Has anyone compared the balanced to the unbalanced outputs? I've used both options direct into my power amps, and I seem to find myself preferring the unbalanced connection - which surprises me somewhat.



That is expected, the unbalanced output is driven by an fully buffered active filter, this allows it to drive a wide variety of cables without difficulty as the active stage compensates for the cable linearity issues.

The balanced stage has a passive filter after the I/V converter, this makes it highly dependent on the load represented by the impedances of the cables you are using and the input impedance of the power amps.

Balanced can be better if the rest of the audio chain can take advantage of differential drive, all of my amps, headphones and speakers use differential drive.

Not much can be done here except to use low(ish) capacitance balanced cable with linear response in the audio band designed for professional use like the Canare L4-6ES or the Gotham GAC/GAC+ series if you want to spend the money. I would steer clear of the Audiophile stuff for the XLR outputs on the LKS. A preamp in the middle might work depending on quality, I have used a Schiit Mjolnir as preamp with decent results.

LKS decision to use an unbuffered passive XLR output is an unfortunate triumph of audio "purity" over common sense.
The LKS004 is a decently designed unit for most parts but it has quite a few shortfalls when it comes to implementation.


----------



## b0bb

penguin140369 said:


> I ran my 003 with the lid off also. Not so aesthetically pleasing to all, but a good way to keep temps down!



Running with the lid off is not a good idea, CCHD-575 has a 50ppm tempco, @100MHz, this is 5kHz.

This is equivalent to adding phase noise to the critical 5kHz midrange region everytime the temp changes by 1ºC, about the magnitude change when the AC or heating kicks in.

Leaving the lid on allows the heat to build up and you have a poor person's equivalent of a crystal oven.


----------



## penguin69

Brill, thanks b0bb as ever for the responses. Always hugely appreciated.

Yes, I did a bit of digging on the SU-1 and found the clicks and pops story earlier in the thread, and also on the vendor website Q&A section. I shall give the unit a miss. Are there other options, or is it best instead to tweak away at the Amanero board as described? I'm guessing yes to the latter, given the LKS I2S implementation isn't so great.

The Schiit Freya has been top of my passive preamp list for the last 3 months, I will pull the trigger shortly, I think.

004 modding will start in 2-4 weeks, once my wrist is usable again post-op.


----------



## vick_v

b0bb said:


> LKS configured the 9038 to re-clock all incoming streams, the custom re-clock logic that you will be paying for on the SU-1 largely goes to waste.



Is this also true for the signal coming from the Amanero board? Would replacing the Amanero with a better re-clocked and buffered source signal bypass the LM317 issues and the main CCHD-575 clock?


----------



## b0bb

penguin140369 said:


> Brill, thanks b0bb as ever for the responses. Always hugely appreciated.
> 
> Yes, I did a bit of digging on the SU-1 and found the clicks and pops story earlier in the thread, and also on the vendor website Q&A section. I shall give the unit a miss. Are there other options, or is it best instead to tweak away at the Amanero board as described? I'm guessing yes to the latter, given the LKS I2S implementation isn't so great.
> 
> ...



The Amanero design is almost 5 years old and I am looking to for a replacement, the 2 generations of XMOS have so far proved to be a disappointment. The Singxer F-1 comes the closest but it is still bus powered.

A passive preamp after the XLR output may not work in your situation given that you can already hear a difference in the outputs, the good thing about the Freya is that it has an active mode.
On the XLR use the active mode, on the RCA use passive.

As far as modding, powering the the USB board with a transformer with an interwinding screen is probably the easiest, for this to work the USB metal can has to be taped up to isolate from the rest of the DAC chassis.


----------



## b0bb

vick_v said:


> Is this also true for the signal coming from the Amanero board? Would replacing the Amanero with a better re-clocked and buffered source signal bypass the LM317 issues and the main CCHD-575 clock?


The USB input is just a USB to I2S converter feeding an internal I2S header, LKS spent most of the effort on making sure this was properly done and it is reclocked.
The enhanced USB interface has its own power supply and does not use the 317, it does not work too well out in  stock form as LKS did not implement the powering and grounding properly. 

I have not been able to find anything that can out perform the Amanero on the LKS at present.


----------



## vick_v

b0bb said:


> The USB input is just a USB to I2S converter feeding an internal I2S header, LKS spent most of the effort on making sure this was properly done and it is reclocked.
> The enhanced USB interface has its own power supply and does not use the 317, it does not work too well out in  stock form as LKS did not implement the powering and grounding properly.
> 
> I have not been able to find anything that can out perform the Amanero on the LKS at present.



I'm waiting on the FIFO and clock boards from Ian here: https://github.com/iancanada/DocumentDownload and I have one of the new XMOS boards to use just for the USB input (it seems to have a better Linux DSD native support than Amanero) http://www.diyinhk.com/shop/audio-kits/107-xmos-dsd-dxd-768khz-high-quality-usb-to-i2sdsd-pcb.html but I was thinking of feeding the output from the above via the I2S Ethernet input of the 004. 
If I understand correctly, I should do it via the Amanero header instead?


----------



## b0bb (Jun 22, 2017)

vick_v said:


> I'm waiting on the FIFO and clock boards from Ian here: https://github.com/iancanada/DocumentDownload and I have one of the new XMOS boards to use just for the USB input (it seems to have a better Linux DSD native support than Amanero) http://www.diyinhk.com/shop/audio-kits/107-xmos-dsd-dxd-768khz-high-quality-usb-to-i2sdsd-pcb.html but I was thinking of feeding the output from the above via the I2S Ethernet input of the 004.
> If I understand correctly, I should do it via the Amanero header instead?



Looked at those a while back, Ian's board did not support DSD, the upcoming v2 does. I dislike having to change sources just to play PCM vs DSD.

The work goes beyond wiring it into the I2S header. You still have to deal with clock sync problems as there 2 clocks in the I2S stream, this is something the got Singxer wrapped around the axle with the clicks and bangs. Talk to @abartels if you want to find out how things can go south with Ian's board, he used it on the AKM dac.

The reclocker in the 9038 cannot be bypassed in the LKS, so most of work reclocking at the I2S side is wasted.
You end up with 2 reclockers  in series, one in Ian's board and the other in the 9038, if the Singxer F-1 with on board reclocker is any indication, this is not a happy state of affairs.

It remains to be seen if the reclocker in Ian's FPGA can do a better job than the ESS one in the 9038.

I would toss the 575 controlling the reclocker on the 9038 and replace it with and ovenized XO (OCXO), I used 2 different OCXOs on the 003 and its on my todo list for the 004

One small saving grace for Amanero is that it now has an in-kernel Linux driver.

(If you really want to experiment to see what Ian's FIFO board is truly capable of, get one of the eval boards from DIYINHK and run it in sync mode to disable the 9038 reclocker.
The LKS 004 is hardstrapped in async mode and is ill suited for the purpose.
With the eval board you can experiment with the various USB interfaces out there, it is a lot cheaper if you make a mistake, 2 people have damaged their 003s here, one recovered, the other did not.

http://www.diyinhk.com/shop/audio-k...t-perfect-volume-control-and-spdif-input.html)


----------



## vick_v

b0bb said:


> Looked at those a while back, Ian's board did not support DSD, the upcoming v2 does. I dislike having to change sources just to play PCM vs DSD.
> 
> The work goes beyond wiring it into the I2S header. You still have to deal with clock sync problems as there 2 clocks in the I2S stream, this is something the got Singxer wrapped around the axle with the clicks and bangs. Talk to @abartels if you want to find out how things can go south with Ian's board, he used it on the AKM dac.
> 
> ...



Thanks for the pointers! 
I am getting the new multi channel boards so they should support DSD and PCM. Also there was an ALSA patch that introduced a short mute when there is change in the stream which eliminated pops when changing from DSD to PCM (my understanding is that the DSD spec requires something like a 50ms mute at the beginning and end of the stream).
I did read abartels blogs about using Ian's FIFO board in his overbuilt DAC but I didn't see any info about him removing the board, I'll reach out to him for more details.
I think I'll try my initial idea and use the Ethernet input and if it's not worse than the Amanero I can at least use native DSD in linux since I'm not very confident he can fix that (it's been several months of almost done).
And maybe get a Pulsar at some point to replace the master XO of the 004.


----------



## penguin69

b0bb said:


> I use isolation transformer + tracking filter.
> https://powervar.com/standard-power-conditioners/
> http://www.digitaltele.com/pdf/emerson/islatrol_lric_ic_plus.pdf



Hi,

FWIW, I use the following for power conditioning/regeneration:

http://www.powerinspired.com/store/ag1500-ac-regenerator-1500w-psu-p-1742.html

It seems to keep the listening experience consistent, however I'm not knowledgeable enough to know whether using this type of product can bring with it trade-offs, e.g. loss of dynamics. 

Anyway, on paper it seems to do a similar job to far more expensive 'audiophile' equivalents.

Looks like the price has gone up a little recently ... I managed to pick up 2 units in the past for 800GBP total.

There is also a lower wattage unit, that retails for 275GBP.

These units are fan-cooled, but the fan is not too noisy and can be cranked down during cooler months to the point where it is inaudible.


----------



## vick_v

penguin140369 said:


> Hi,
> 
> FWIW, I use the following for power conditioning/regeneration:
> 
> ...



I got the 500W device too and while I can't tell if it has any effect I do like the fact of hopefully clean power going to all my devices.


----------



## mb3

b0bb said:


> The USB-I2S interfaces I use needs about 10W, so the relays will need to switch at least 3A@3.3V, the Takamisawa is not rated for this.
> 
> Gold has a low boiling point and will evaporate in the arc instead of oxidizing, I would use relays with Palladium or Indium alloys in the contacts minus the gold plating.The Takamisawa is using a Silver-Palladium alloy under the plating.
> 
> ...





b0bb said:


> LKS configured the 9038 to re-clock all incoming streams, the custom re-clock logic that you will be paying for on the SU-1 largely goes to waste.
> The cost is within 50USD of the Pulsar OCXO, this replaces the XO in the DAC at the the very centre of the 9038's re-clock logic, I think that mod has better value for the money.
> 
> LKS paid little attention to the I2S interfaces, most of the logic is powered by the slow and somewhat noisy LM317, the LM317 is a huge step backward from the LT317 used on the 003.
> ...



Hi B0bb,
From your experience, would you expect that upgrading to isolated toroidal transformers will help to improve sound quality from this device? - which is already good imo. Thank you.


----------



## b0bb

mb3 said:


> Hi B0bb,
> From your experience, would you expect that upgrading to isolated toroidal transformers will help to improve sound quality from this device? - which is already good imo. Thank you.



Yes but only if the LKS004 grounding and power routing problems are   fixed first.

2 sets of transformers are required one for the digital devices such as the media player, computer, CD player etc and another for the analog side such as headphone amps, power and preamps and the DAC.
Only join the common ground and neutral at the power outlet on the wall (if you have access to an outlet on another circuit, that is better but not always practical and requires knowledge of the house wiring).

Keep in mind RFI filters are needed to isolate incoming interference as well as isolating the digital and analog parts of the audio chain from each other. (This is something LKS forgot when they wired in the enhanced USB board).

Avoid plugging the analog and digital devices on the same isolation transformer or AC re-generator, this is one reason why some people do not see a difference when using just 1 big unit for the whole setup.

If you have the enhanced USB board, the LKS 004 internally joins the digital and analog power lines, this must be corrected (separate transformer and insulated USB metal shield) first before any improvement can be seen.
On the standard USB board, the USB metal shield has to be insulated  as it can join the digital and analog grounds thru touching the DAC metal work.


----------



## Audio4Fun

Hi, I’m new to the Head-Fi forum, but I had been reading this thread for a very long time, now I had purchased a MH-DA004 that is now burning for about 6 days, first test was not as good as I expected, but had to wait for new tests after 2 weeks burning period.

I want to change the stock fuse for a better quality one, but I found the stock fuse is rated at 3.15A (slow blow type), this seems to me to be a very big value for the MH-DA004 @220v/50Hz, is this correct?

Thanks


----------



## penguin69

b0bb said:


> Avoid plugging the analog and digital devices on the same isolation transformer or AC re-generator, this is one reason why some people do not see a difference when using just 1 big unit for the whole setup.



This is good to know. Mine are indeed separated in this way - but that is down to luck more than sound judgement!


----------



## mb3

b0bb said:


> Yes but only if the LKS004 grounding and power routing problems are   fixed first.
> 
> 2 sets of transformers are required one for the digital devices such as the media player, computer, CD player etc and another for the analog side such as headphone amps, power and preamps and the DAC.
> Only join the common ground and neutral at the power outlet on the wall (if you have access to an outlet on another circuit, that is better but not always practical and requires knowledge of the house wiring).
> ...


Sounds good - thank you. Insulating the usb input works well. I have my dac and computer powered from an apc line-r 1200va with surge and emi filters in place.
http://www.apc.com/shop/au/en/products/Line-R-1200VA-Automatic-Voltage-Regulator/P-LE1200I
http://www.poweronaustralia.com.au/product/eaton-psfi/
I was thinking that upgrading the power supplies to something like this https://www.plitron.com/default-factory-specs/medical-grade-toroidal-transformers/
would be an improvement - along the lines of the kitsune level 3 upgrade...


----------



## b0bb

APC uses a switchmode type regulator and can be quite noisy, the Eaton RFI filter should be placed between the AVR and the dac.

Stock transformers are already quite good and has the required electrostatic shield between the primary and secondary windings, expect, at best an incremental improvement.
I think powering the enhanced USB interface with its own transformer will give better results and if you do not have the enhanced USB to I2S interface, get it as well as the other I2S inputs on the LKS004 is done poorly done in comparison.


----------



## mb3

b0bb said:


> APC uses a switchmode type regulator and can be quite noisy, the Eaton RFI filter should be placed between the AVR and the dac.
> 
> Stock transformers are already quite good and has the required electrostatic shield between the primary and secondary windings, expect, at best an incremental improvement.
> I think powering the enhanced USB interface with its own transformer will give better results and if you do not have the enhanced USB to I2S interface, get it as well as the other I2S inputs on the LKS004 is done poorly done in comparison.


Hi b0bb, that's how I have it set up, avr >eaton>lks. Probably should use a different avr but this works ok. I have the upgraded version with the amanero USB card - which seems to be the best available option for USB input. Thank you for your tips.


----------



## kirbyt

I find all this very interesting read, a question directed to bobb is it plausible to wire the singxer directly into where the amenaro board pins in? Would that be of benefit as apposed to the HDMI i2s input? I'm a bit of a newb to all this but if I'm interpreting your comments correctly the amanero i2s input to board is treated with greater care vs the i2s sockets on the dac.


----------



## b0bb

kirbyt said:


> I find all this very interesting read, a question directed to bobb is it plausible to wire the singxer directly into where the amenaro board pins in? Would that be of benefit as apposed to the HDMI i2s input? I'm a bit of a newb to all this but if I'm interpreting your comments correctly the amanero i2s input to board is treated with greater care vs the i2s sockets on the dac.



Possible in theory but whether it works in practice is a different matter.

There are no commonly agreed standards for I2S ,so basic items like the termination impedances is left up to the manufacturer. A 44.1k stream generates a 2.8MHz bitstream so the transmitter and receiver must be properly terminated.

Similarly, there no clear rules to govern behavior during a mode change, for example from PCM to DSD or a sample rate change. This one is responsible for much of the problems with click and bangs some people have experienced.

LKS matched the internal I2S input to the Amanero board and if you change this you have to re-do all the work they did with the Amanero card.


----------



## kirbyt

Well ok I went and took the questionable power side of the amenaro out and jumped the board 5v input via an lps-1. Seems to be an improvement for me as I really wasn't enjoying the amenaro input and preferred the singxer via i2s up till now.


----------



## b0bb

kirbyt said:


> Well ok I went and took the questionable power side of the amenaro out and jumped the board 5v input via an lps-1. Seems to be an improvement for me as I really wasn't enjoying the amenaro input and preferred the singxer via i2s up till now.



Did you insulate the USB socket from the chassis?
The back panel comes off easily giving access to the USB socket.


----------



## kirbyt

Yup I sure did


----------



## dacusb

b0bb said:


> CGW caps marked, you can leave the existing cap in place and just solder the CGWs to the underside



Hi b0bb,

How many CGW caps do I need to add?
Thank you


----------



## b0bb

dacusb said:


> Hi b0bb,
> 
> How many CGW caps do I need to add?
> Thank you


8pcs


----------



## dacusb

b0bb said:


> 8pcs


Hi b0bb.

Thank you very much for your prompt reply.
Can you help further by advising where to get those CGW caps?
Many thanks.


----------



## TPSRA (Jul 19, 2017)

Hi b0bb
I wonder which one is better, use LKS's Amanero usb receiver USB-100 with linear 5V to connect to DA004,
or do the on board Amanero modding you mentioned above, which will lose the warranty I guess?


----------



## Whitigir (Jul 20, 2017)

b0bb said:


> Yes but only if the LKS004 grounding and power routing problems are   fixed first.
> 
> 2 sets of transformers are required one for the digital devices such as the media player, computer, CD player etc and another for the analog side such as headphone amps, power and preamps and the DAC.
> Only join the common ground and neutral at the power outlet on the wall (if you have access to an outlet on another circuit, that is better but not always practical and requires knowledge of the house wiring).
> ...




Bobb, what transformer specs should I use to help the Amenero ? I am going to just isolate the USB ground from the chassis ground first.  I am interested in separating the amernero like you mentioned.  Using my Walkman and it docking station, I am not too worry about the noises passing through from the host to the Amenero, but isolating for galvanic is a good step

Woaa, just a simple modification of isolating the USB away from the main chassis net in a huge improvements.  Finer trebles, less noises !! Thanks Bobb


----------



## b0bb (Jul 20, 2017)

Whitigir said:


> Bobb, what transformer specs should I use to help the Amenero ? I am going to just isolate the USB ground from the chassis ground first.  I am interested in separating the amernero like you mentioned.  Using my Walkman and it docking station, I am not too worry about the noises passing through from the host to the Amenero, but isolating for galvanic is a good step
> 
> Woaa, just a simple modification of isolating the USB away from the main chassis net in a huge improvements.  Finer trebles, less noises !! Thanks Bobb



6-8Vac 10-15VA, do not exceed 15VA, use a unit that you can physically fit into the case, any type will do, a RFI filter should be used on the AC input, its job is to prevent noise from the USB interface leaking into the AC mains.
If you can get a transformer with an electrostatic shield, do so.
Do not share this RFI filter with the other transformers on the DAC.


----------



## b0bb (Jul 20, 2017)

TPSRA said:


> Hi b0bb
> I wonder which one is better, use LKS's Amanero usb receiver USB-100 with linear 5V to connect to DA004,
> or do the on board Amanero modding you mentioned above, which will lose the warranty I guess?


The USB-100 does not appear to have galvanic isolation on the I2S output, allowing RF noise an unobstructed path into the DAC, the 9038 is very sensitive to RF noise.

USB input on the USB-100 is not insulated from the chassis, similar to the issue seen on the 004.


----------



## brickears

kirbyt said:


> Well ok I went and took the questionable power side of the amenaro out and jumped the board 5v input via an lps-1. Seems to be an improvement for me as I really wasn't enjoying the amenaro input and preferred the singxer via i2s up till now.


Which pins on the Amanero board did you use to power with just the LPS-1 ?


----------



## Lennym (Jul 31, 2017)

I have had my LKS 004 for about 8 weeks and have enjoyed it very much.  I have the upgraded Amanero board and I run ripped DSD files through it perfectly.  I have insulated the USB port from the chassis.  Thank you b0bb.  It sounds great with all sorts of files and with CDs, I can only compare it to my Oppo 105, except that there is no comparison.  I've been a mostly analog listener, but now I share my time equally with digital.  Never did that before.

I have posted over at the 004 thread.  Like everyone else I have been concerned about the heat and its effect on adjacent caps and I have installed these heatsinks, each over two transistors: http://uk.rs-online.com/web/p/heatsinks/1899306/?searchTerm=1899306  They seem to be working well.  Following the lead of the poster who suggested these I'll also install some sil-pads.

However on Hiendy, a Chinese forum (I don't read Chinese) also concerned with the heat and the factory's non-response to inquiries on the subject, a poster recently posted the following that I thought might be of interest here:

"Today, into the Zo kind of heatsink, comes with stickers. With a cable fixed, boot a clock with the fingers touch heatsink good heat. But there is hot to bounce (due to the younger thermometer is broken.) Estimated regulator working temperature can be controlled Department of 50 degrees below." Google Transl.


----------



## Whitigir

Any pulsar mod on 004 yet ?


----------



## Carlo7

b0bb said:


> Shenzhen Audio is also selling it
> http://www.shenzhenaudio.com/l-k-s-...nnel-decoder-amanero-usb-dsd-dac-crystek.html





b0bb said:


> LKS configured the 9038 to re-clock all incoming streams, the custom re-clock logic that you will be paying for on the SU-1 largely goes to waste.
> The cost is within 50USD of the Pulsar OCXO, this replaces the XO in the DAC at the the very centre of the 9038's re-clock logic, I think that mod has better value for the money.
> 
> LKS paid little attention to the I2S interfaces, most of the logic is powered by the slow and somewhat noisy LM317, the LM317 is a huge step backward from the LT317 used on the 003.
> ...


----------



## Carlo7

Bobb, I enjoy reading your posts. I have the Lks 004 amazing creature ! I have about 400 hrs in and ready for transformer and usb tweeks. Did you try ear sd40 yet and what other small things can i do to improve ?
Thanks carlo7


----------



## b0bb

Whitigir said:


> Any pulsar mod on 004 yet ?





Carlo7 said:


> Bobb, I enjoy reading your posts. I have the Lks 004 amazing creature ! I have about 400 hrs in and ready for transformer and usb tweeks. Did you try ear sd40 yet and what other small things can i do to improve ?
> Thanks carlo7



LKS is starting to address some of the issues such as heat and insulating the USB connector.

I am waiting to see where this will lead, once components are removed from the board the warranty becomes void, the mods I have described until now are reversible and do not require desoldering parts of the DAC.


----------



## Tomus4

Hi,
New opa for MH-DA003: http://allegro.pl/wzmacniacz-operacyjny-dyskretny-os-opamp-dual-i6889250300.html
V5 in the output stage was the best for me (I tried DEXA - in my system was to dry with non control in bass).
Staccato Audio OS crush V5 in all aspects, V5 seems to be dry, non musical compare to Staccato. Best effect after 70...80 hours of warm up.


----------



## penguin69

I spent 1.5 hours today doing an A-B comparison of the Chord Dave with the LKS Audio MH-DA004. The comparion was performed with just a couple of tracks from an album I know well.

Normally, I struggle to hear significant differences between DAC's, but the signature of these two was quite different. The Dave came out on top, but the LKS gave a good account of itself. (Let's not forget that the Dave is around 6x the price.)

The 004 is the best Sabre DAC I've heard, but in its current state it lacks the life and dynamics of the Dave. The latter also has more lower-mid 'weight' to its sound. But the 004 is no less refined. It just sounds like it is more reserved, happy to sit back and work within its limits.

This experiment has motivated me to want to mod the 004, particularly on the analogue side.

In a couple of weeks' time I will be getting the Dave on an extended loan. If anyone wants me to proffer further comparisons, let me know. I still think the 004 has all the potential, it's just a case of realizing it.


----------



## ti5002000

penguin140369 said:


> I spent 1.5 hours today doing an A-B comparison of the Chord Dave with the LKS Audio MH-DA004. The comparion was performed with just a couple of tracks from an album I know well.
> 
> Normally, I struggle to hear significant differences between DAC's, but the signature of these two was quite different. The Dave came out on top, but the LKS gave a good account of itself. (Let's not forget that the Dave is around 6x the price.)
> 
> ...



i had a Chord Dac in the past and altough i don´t heard Dave ,in my experience, the lks mh-004 only misses this dynamic ,life and impact that you are talking about.But in comparasion,the LKS is much better value for Money and also has some better micro details.For the price it is hard to beat.
Maybe the capacitors that Bobb talked about can improve this...


----------



## penguin69

Yes, the LKS is definitely much better value for money. 

I wonder where the difference lies. The 004 doesn't sound like it's inferior, or lacking in detail; it just seems more restrained.


----------



## Lennym (Sep 16, 2017)

If the 004 can be compared to the $10,500 DAVE we're in good company--and with the possibility of mods.

In his review of the DAVE, Stereophile's editor John Atkinson also notes its strong bass-mid-bass performance using classical piano as his reference recording.  Then he goes on to compare it to a $20,000 Meridian DAC.  He prefers the bass (on the piano)  of the DAVE, but the higher frequencies (a violin) of the Meridian.

Two comments.  You have used "just a couple of tracks from an album I know well."  No problem, except that a wider variety of software might give interesting results.  By the way, could you share what you used, and was it from a CD or downloaded files and in what format?

Also, we (and professional reviewers these days--as Atkinson does) are always comparing one device to another rather than to the real thing.  The real thing being live un-amplified music.  That's the comparison that was made when serious high fidelity and stereo component reviewing got its start.  In his review Atkinson leaves us guessing as to which of these two five-figure DACs brings us closer to the source.


----------



## penguin69

Lennym said:


> If the 004 can be compared to the $10,500 DAVE we're in good company--and with the possibility of mods.
> 
> In his review of the DAVE, Stereophile's editor John Atkinson also notes its strong bass-mid-bass performance using classical piano as his reference recording.  Then he goes on to compare it to a $20,000 Meridian DAC.  He prefers the bass (on the piano)  of the DAVE, but the higher frequencies (a violin) of the Meridian.
> 
> ...



Mid-bass is where I heard a difference also. It was fuller on the Dave. Alhough that doesn't necessarily mean 'better'. (I prefer it but that's personal preference.)

The album was The Age of Plastic by The Buggles, played through Tidal. It wasn't an ideal demo environment for me as it was in a large carpeted room (upstairs of local hifi shop), and unfamiliar components (Naim integrated amp, unfamiliar speakers.) My home listening environment is a smaller, non-carpeted room. I also use Tidal, but the amp and speaker set-up is entirely different: Kudos Titans driven by Quad II 80's and Cyrus Mono x300 Sigs.

I'll be getting the Dave on home demo shortly, and will listen to mainly live performances - as that tends to be my benchmark. Stuff like 'Made in Japan' by Deep Purple, and 'Live at the Point' by Christy Moore.


----------



## simon 2

I have put blu-tack on the nichicon caps and that gives it a more solid  sound .


----------



## penguin69

Have you tried the white version of blu-tak?


----------



## simon 2

no


----------



## rafabro

@B00b or someone who know...

Friend of my replaced OP-AMPs at Crystek clock to polish/danish STACCATO OSC OP-AMPs with great result. Once he was experimenting with other opamps at rear side and by mistake he forgot to put back one of them and then turn on DAC with 3 opamps only.
Music was playing as normal before he realize what he did.

Why DAC was playing music without one opamp?
How important are back side opamps for XLR connection? Is it still wort investment to replace them for XLR?

thanks in advance


----------



## b0bb (Oct 21, 2017)

rafabro said:


> @B00b or someone who know...
> 
> Friend of my replaced OP-AMPs at Crystek clock to polish/danish STACCATO OSC OP-AMPs with great result. Once he was experimenting with other opamps at rear side and by mistake he forgot to put back one of them and then turn on DAC with 3 opamps only.
> Music was playing as normal before he realize what he did.
> ...


The pair of opamps closest to the rear panel convert the balanced signal from the current-voltge (I/V) converter  to unbalanced for the RCA outputs, the XLR signal comes off the I/V converter directly. These opamps have no effect on the XLR operation.

If the I/V converter opamp is removed the DAC might appear to function as the 9018 goes into voltage mode but will cause long term damage to the speaker tweeter as there is substantial conversion aliasing noise above 22kHz that is not removed causing the tweeter voice coils to be overdriven, burning it out eventually.

The I/V converter opamp on the LKS is  the part of the post conversion filter responsible for removing the aliasing noise


----------



## rafabro

That's perfect explanation b0bb, thank you very much!


----------



## penguin69

b0bb said:


> If the I/V converter opamp is removed the DAC might appear to function as the 9018 goes into voltage mode but will cause long term damage to the speaker tweeter as there is substantial conversion aliasing noise above 22kHz that is not removed causing the tweeter voice coils to be overdriven, burning it out eventually.



Digital has been around for a long time now, and aliasing effects well known. I've often wondered why this 'digital' problem isn't handed off to 'analogue' manufacturers, who presumably could correct this with a filter after the crossover to remove this damaging aliasing noise?


----------



## Lennym

simon 2 said:


> I have put blu-tack on the nichicon caps and that gives it a more solid  sound .



Any chance for a picture?


----------



## b0bb

penguin140369 said:


> Digital has been around for a long time now, and aliasing effects well known. I've often wondered why this 'digital' problem isn't handed off to 'analogue' manufacturers, who presumably could correct this with a filter after the crossover to remove this damaging aliasing noise?



The DAC should be the last block in the chain before the analog power amp, this means digital processing for the crossover to get the best possible results.
Ideally the DAC and poweramp should be one and the same but that tech is a bit  of hit and miss at the moment.


----------



## guneyt

Hi folks, what are u thinking about the coupling capacitor located at the input of spdif ? There is 0.1uf film Wima in each input. Do you think a better coupling capacitor works better here ? Someone says no because it is in digital domain. But I'm thinking a better cap especially with a very low dielectric absorption will do somethings good in jitter domain..


----------



## Whitigir

Isn't Wima good enough?


----------



## guneyt

Whitigir said:


> Isn't Wima good enough?



I do not know.. I am also looking for the answer to this..

please take a look at Lampizator Golden Gate dac..He wrote
"Digital input SPDIF capacitor is Jupiter Wax Copper 100nF or Mundorf Silver Oil Supreme"

I would easily pull the trigger for Jupiter copper if it was cheap..


----------



## b0bb

The WIMA cap is the DC blocking capacitor for Murata SPDIF transformer.

SPDIF operates between 1.5MHz (44k sampling) and 10MHz (192k sampling), the WIMA is in series with the signal  and the transmission loss thru that cap will affect the shape digital pulse train.

This in-turn determines the clock extraction accuracy from the SPDIF stream and the final jitter performance.

The key parameter here is the dissipation factor between 1MHz and 10MHz. Most reputable cap manufacturers like WIMA provide some data usually up to 100kHz, this is not ideal but is better than nothing at all.

You should ask the makers of the caps you interested in to see if they can provide that info.


----------



## guneyt

Thank you for your prompt reply b0bb.


----------



## Tomus4 (Dec 2, 2017)

Hi,

Is anybody who replaced NICHICON FG 47uF/50V around the opas to the another Electrolytic Capacitor like:
- Elna Silmic II - 220uF 25V suggested by Burson
- Black Gate Standard Type - I found in the network 100uF 50V
Is it sense to do this exercise?

Next question is about RCA output caps.
b0bb sugest to replaced it by the Blue 63V 0.033uF/33nF 1% polypropylene is from EVOX/Rifa and I did this
Is anybody who replaced it by the one of HiEnd capacitor example V-Cap CuTF or another Copper Foil Capacitors like https://www.hificollective.co.uk/ca...j-0033uf-600v-kpcu-copper-foil-capacitor.html ?

What about replacing RCA output resistors?


----------



## rafabro

Nichicon FG it's always good to replace. Harsh sounding caps...


----------



## Tomus4

rafabro said:


> Nichicon FG it's always good to replace. Harsh sounding caps...



What to choose/check?


----------



## rafabro

Chemicon LXV , Elna Silmic II definitely worth to try


----------



## Tomus4

rafabro said:


> Chemicon LXV , Elna Silmic II definitely worth to try



Thank you. What do you thing about Nippon kme/sme? It is the same manufacturer as Chemicon LXV, isn't it?


----------



## rafabro

*NIPPON CHEMI-CON  *http://www.chemi-con.co.jp/e/company/index.html


----------



## guneyt

b0bb, what do you think about the de-couplings of the balanced out section on mh-da002 ? There are two Nichicon Gold electrolytics not like films seen on mh-da003 (design is also slightly different) If I'm not wrong you have already replaced those caps with polystyrene ones. Do you have any idea for upgrading Golds ?


----------



## b0bb (Dec 15, 2017)

guneyt said:


> b0bb, what do you think about the de-couplings of the balanced out section on mh-da002 ? There are two Nichicon Gold electrolytics not like films seen on mh-da003 (design is also slightly different) If I'm not wrong you have already replaced those caps with polystyrene ones. Do you have any idea for upgrading Golds ?



The polystyrene caps on the 003 is for the final stage analog filter.
003 uses Panasonic FMs not the Nichicon FGs for power supply bypass, post a picture of the 002 and indicate the caps you wish to replace.


----------



## Lennym

Looking for an AC current line conditioner or regenerator specifically in front of my LKS 004.  Anyone have success with a 110 Volt unit?


----------



## guneyt

b0bb said:


> The polystyrene caps on the 003 is for the final stage analog filter.
> 003 uses Panasonic FMs not the Nichicon FGs for power supply bypass, post a picture of the 002 and indicate the caps you wish to replace.



H, I'm talking about the low pass filter caps (C10, C11) on the schematic of 003 shared on post #210. 
Filter design of 002 looks like slightly different C9 not available.. There are two caps (47uf Nichicon FG) on the positions of C10 & 11


----------



## guneyt (Dec 21, 2017)

one more question about the bypass caps of op-amps power rail.  Have you tried a single xr7 ceramic on that positions..no films no electrolytics only a ceramic ?
Take a closer look to Reimyo 777 dac.. one of the best I have ever heard. it uses a ceramic only. I have Sonic Imagery 994 op-amps on IV and rca buffer.. According to Sonic, power rail bypass caps should be used with adding a small resistance.. I have had troubles many time with film, tantalum or low esr electrolytic located so closely after regulator without adding resistance. they are oscilating.. only with a reasonable distance (say min 8-10cm) they are getting fine.


----------



## Carlo7

b0bb said:


> LKS is starting to address some of the issues such as heat and insulating the USB connector.
> 
> I am waiting to see where this will lead, once components are removed from the board the warranty becomes void, the mods I have described until now are reversible and do not require desoldering parts of the DAC.


----------



## Carlo7

Bobb, have you or anyone compared Ares Amanaro dac to Lks 004 ? Not enough posts on this one.

Thanks carlo7


----------



## b0bb (Dec 24, 2017)

guneyt said:


> one more question about the bypass caps of op-amps power rail.  Have you tried a single xr7 ceramic on that positions..no films no electrolytics only a ceramic ?
> Take a closer look to Reimyo 777 dac.. one of the best I have ever heard. it uses a ceramic only. I have Sonic Imagery 994 op-amps on IV and rca buffer.. According to Sonic, power rail bypass caps should be used with adding a small resistance.. I have had troubles many time with film, tantalum or low esr electrolytic located so closely after regulator without adding resistance. they are oscilating.. only with a reasonable distance (say min 8-10cm) they are getting fine.



The 9018 has a peak output current of 32mA, on the LKS the regulators are about 2 inches from the I/V converter so most of the transient charge is supplied by the bypass cap and it needs a minimum of 10uF to function properly, typically values of 47-100uF is used.
This is a large value for ceramic caps, there are 2 issues with large value ceramic caps, sensitivity to magnetic fields and temperature .

X7R ceramic materials are ferromagnetic and the I/V converter is quite close to the transformers.

X7R specs provide for a ±15% capacitance variation  over the operating temp range but the fine print here is the change is not linear and greatly depends on who made the cap.

In practice I use 3 caps in parallel, electrolytic, film and ceramic spaced 2 orders of magnitude apart for example 47uF, 0.47uF, 0.0047uF, The ceramic cap I use is NPO/COG rather than X7R

002 uses the LM/LT317 regulator for the DAC supply, data sheet for the device specifically warns about using very low ESR high frequency (> 100Khz) bypass on the output to avoid instability. 003 uses the LT1763 which has no such limitations.

The 994 opamp needs the supply line as clean as possible, on the 002 I do not expect that you will be able to use it to full capability.


----------



## b0bb

Carlo7 said:


> Bobb, have you or anyone compared Ares Amanaro dac to Lks 004 ? Not enough posts on this one.
> 
> Thanks carlo7


I have not made a comparison.


----------



## guneyt (Dec 26, 2017)

b0bb said:


> 002 uses the LM/LT317 regulator for the DAC supply, data sheet for the device specifically warns about using very low ESR high frequency (> 100Khz) bypass on the output to avoid instability. 003 uses the LT1763 which has no such limitations.
> 
> The 994 opamp needs the supply line as clean as possible, on the 002 I do not expect that you will be able to use it to full capability.



Thank you b0bb..
I had replaced all regulators on 002. I'm using  two TPS7A4700 for 3.3v analogs and  four LT3045-S for 3.3v & 1.2v  dac rails. These regulators are good..especially new LT3045 made astonishingly good result. Also I'm using dexa external clock with a high grade psu..  When I was replacing regulators I did not touch opamp dc bypass caps (47uf Gold + 0.1 MKS) .. Last week I added 8x 120pf CGW corning glass to the rig.. result is not good.   I'm waiting them to be settled on but not hoping that it will improve..


----------



## b0bb

guneyt said:


> Thank you b0bb..
> I had replaced all regulators on 002. I'm using  two TPS7A4700 for 3.3v analogs and  four LT3045-S for 3.3v & 1.2v  dac rails. These regulators are good..especially new LT3045 made astonishingly good result. Also I'm using dexa external clock with a high grade psu..  When I was replacing regulators I did not touch opamp dc bypass caps (47uf Gold + 0.1 MKS) .. Last week I added 8x 120pf CGW corning glass to the rig.. result is not good.   I'm waiting them to be settled on but not hoping that it will improve..


CGW corning caps should only be used to bypass the power supply caps, should not be used  on the direct audio path.


----------



## aggielaw

I'm interested in experimenting with aftermarket fuses as well.  When I pulled the stock fuse from my D004 it was wrapped in bronze foil.  Anyone know why this was done?

Also, I've seen the 3.15A 250Hz value reported for the D003, but when I enlarged photos of the D004's stock fuse it appears to say "T6 15A 250Hz!"  My amp's line fuse is only 6.3A, so this can't possibly be correct.  Does anyone know what the proper fuse value is?  I'm thinking of trying the highly-acclaimed Synergistic Red in it, which is known to blow too easily.  To get the Synergistic Red to perform like "normal" fuses rated at 3.15A (or whatever the proper value for the D004 is) what should I bump the Red's amp rating up to?

Thanks guys!


----------



## Audio4Fun

aggielaw said:


> I'm interested in experimenting with aftermarket fuses as well.  When I pulled the stock fuse from my D004 it was wrapped in bronze foil.  Anyone know why this was done?
> 
> Also, I've seen the 3.15A 250Hz value reported for the D003, but when I enlarged photos of the D004's stock fuse it appears to say "T6 15A 250Hz!"  My amp's line fuse is only 6.3A, so this can't possibly be correct.  Does anyone know what the proper fuse value is?  I'm thinking of trying the highly-acclaimed Synergistic Red in it, which is known to blow too easily.  To get the Synergistic Red to perform like "normal" fuses rated at 3.15A (or whatever the proper value for the D004 is) what should I bump the Red's amp rating up to?
> 
> Thanks guys!




Hi, My DA004 comes with 3.15A slow blow fuse, I had replaced it with a Hi-Fi Tuning Supreme Series with very good results.

Regards!!


----------



## dcguy73

Lennym said:


> Looking for an AC current line conditioner or regenerator specifically in front of my LKS 004.  Anyone have success with a 110 Volt unit?


 
I picked up a PS Audio P5 regenerator for my audio setup, and all three of my sources (including LKS) improved a lot. But it sounds like you want one just for the LKS?


----------



## Lennym

b0bb said:


> 6-8Vac 10-15VA, do not exceed 15VA, use a unit that you can physically fit into the case, any type will do, a RFI filter should be used on the AC input, its job is to prevent noise from the USB interface leaking into the AC mains.
> If you can get a transformer with an electrostatic shield, do so.
> Do not share this RFI filter with the other transformers on the DAC.



Has anyone done this mod and/or can recommend parts meeting b0bb's specs?


----------



## wushuliu

b0bb said:


> You can get it either at mouser or digikey
> 
> http://www.mouser.com/ProductDetail...=sGAEpiMZZMsC2cQJVRBSBUVTnCXPHX6IDcln7PotGtA=
> http://www.digikey.com/product-detail/en/AOCJY1-100.000MHZ/535-10656-ND/2441422



Hi, I happened to come across your posts on different clocks and am curious if you've tried or have any thoughts about the Crystek CVSS Sine wave output clocks. Datasheet here.

Edit: I just noticed the date on the datasheet is 3/18, so maybe these are brand new to the market.


----------



## b0bb

wushuliu said:


> Hi, I happened to come across your posts on different clocks and am curious if you've tried or have any thoughts about the Crystek CVSS Sine wave output clocks. Datasheet here.



LKS uses square wave clocks on 3.3V LVTTL, CVSS will require 5V to 3.3V level shifting plus conversion to square wave output, it requires utmost care to preserve the XO performance.

This is best left up to the manufacturers, there are equivalent or better XOs that have the right output characteristics for the LKS.


----------



## demos (Aug 30, 2018)

I am looking to change the clock on my DA004. I measure the voltage supply of the clock on the cchd575 on my DA004 today. Quite surprisingly found out it has 4.83V on it. I measure serval time on Vdd to GND and output pin of the clock LDO it's all 4.83V no kidding. Is this kind of voltage safe for the clock? For long term operation?

The DAC work perfectly all the time. So the 575 clock is working under this 4.83v voltage on my dac. My 004 is just brought recently, it use LT3042 for power supply for the clock. It also has a earlier version, which use TPS7A4700 to power the clock.

Really wondering if all the 004 all has this hight voltage on the clock. I check the data sheet on the cchd-950 it has a Absolute Maximum Input Supply Voltage of 6.0V, 575 did not mention Absolute Maximum Voltage. And the PULSAR clock has the Maximum Voltage of 4.0V


----------



## Whitigir

I don’t think pulsar sell 100M anymore right ?


----------



## demos

Whitigir said:


> I don’t think pulsar sell 100M anymore right ?



They say not plan to restock the 100m for now


----------



## demos

I take off the cchd575 on the 004, put in a 950x, there is significant improvement on the 950x, WOW


----------



## Whitigir

demos said:


> I take off the cchd575 on the 004, put in a 950x, there is significant improvement on the 950x, WOW


I was thinking of doing this.  Tell me more about improvements.  The 950x is twice as good in spec


----------



## demos

Whitigir said:


> I was thinking of doing this.  Tell me more about improvements.  The 950x is twice as good in spec



The 950x bring improvement on 3D imaging, instrument separation, sound staging and presentation, sound more natural and accurate, Treble is more smoother. 
Like *@b0bb* say "004 falls apart on complex highly compressed tracks", this is what it is on 575, the 950x has better layering, 3D imaging, instrument separation. 
It sound Slightly warmer on the 950x, bass has better texture, more extended

Really wondering how it would bring on a Pulsar clock, if there is 100mhz available 

look like the 4.8V is way too hight for clock, it works on the crystek clock, looking to lower the voltage.


----------



## Whitigir (Aug 30, 2018)

Lks004 uses LT1763.  Isn’t this capable of 500mA ? That means OCXO will work ? Actually, at turn on, it needs 3.6W
https://www.mouser.com/ProductDetai...JVRBSBQ7qx1B6RYgm%2bL8c/KIWJXzTGwc7Dapf%2bw==

I will just use 950X when the time come instead


----------



## b0bb (Aug 30, 2018)

demos said:


> I am looking to change the clock on my DA004. I measure the voltage supply of the clock on the cchd575 on my DA004 today. Quite surprisingly found out it has 4.83V on it. I measure serval time on Vdd to GND and output pin of the clock LDO it's all 4.83V no kidding. Is this kind of voltage safe for the clock? For long term operation?
> 
> The DAC work perfectly all the time. So the 575 clock is working under this 4.83v voltage on my dac. My 004 is just brought recently, it use LT3042 for power supply for the clock. It also has a earlier version, which use TPS7A4700 to power the clock.
> 
> Really wondering if all the 004 all has this hight voltage on the clock. I check the data sheet on the cchd-950 it has a Absolute Maximum Input Supply Voltage of 6.0V, 575 did not mention Absolute Maximum Voltage. And the PULSAR clock has the Maximum Voltage of 4.0V



The supply voltage to the XO is  high, on mine  the supply voltage is 3.3V between pins 2 and 4 on the XO and the clock output (Pin 3 on XO ) DC level  sits at about 1.5V.
Supply pins are the ones marked "O" in your picture.

My DAC uses the TPS7A47 regulator, if you are planning to use the Pulsar the voltage output of the regulator on the board has to be changed as it is a 3.3V part.


----------



## demos

b0bb said:


> The supply voltage to the XO is  high, on mine  the supply voltage is 3.3V between pins 2 and 4 on the XO and the clock output (Pin 3 on XO ) DC level  sits at about 1.5V.
> Supply pins are the ones marked "O" in your picture.
> 
> My DAC uses the TPS7A47 regulator, if you are planning to use the Pulsar the voltage output of the regulator on the board has to be changed as it is a 3.3V part.




Thanks for your info b0bb, looks like the voltage needs to be lower. Check the LT3042's datasheet and the 004's PCB, its voltage is set by the resistor near the regulator. Just change it to a 33k ohm it will output 3.3V


----------



## b0bb

demos said:


> Thanks for your info b0bb, looks like the voltage needs to be lower. Check the LT3042's datasheet and the 004's PCB, its voltage is set by the resistor near the regulator. Just change it to a 33k ohm it will output 3.3V



Your DAC appears to have the 33k resistor already, The color balance of the photo is off. Is the color band on the MELF resistor orange-orange-black-red-brown ?
If it is you may have a dry solder join, reflow the connection to fix


----------



## demos (Aug 31, 2018)

b0bb said:


> Your DAC appears to have the 33k resistor already, The color balance of the photo is off. Is the color band on the MELF resistor orange-orange-black-red-brown ?
> If it is you may have a dry solder join, reflow the connection to fix



Believe or not, I check the resistor's leg more carefully and found out one leg is sitting there left unsoldered  It's on the other side I usually facing. It connects to the PCB just by surface contact.

 It always look like a yellow-yellow color band on the resistor to me. Until I check out the resistor color code and found yellow=4 so I think the resistor value could be 44something ohm, about right on LT3042's output voltage. But if calculate precisely 44k ohm resistor should make LT3042 output 4.4V. So It was really weird. I am just going to unsolder that resistor to measure what exact value it would be, after I receive the 33.2k ohm metal film resistor I ordered. So now It solve all the question It's no needed. Thanks b0bb for this!!


----------



## demos (Aug 31, 2018)

Whitigir said:


> Lks004 uses LT1763.  Isn’t this capable of 500mA ? That means OCXO will work ? Actually, at turn on, it needs 3.6W
> https://www.mouser.com/ProductDetail/ECS/ECOC-2522-100000-3FC?qs=sGAEpiMZZMsC2cQJVRBSBQ7qx1B6RYgm%2bL8c/KIWJXzTGwc7Dapf%2bw==
> 
> I will just use 950X when the time come instead



The SC-cut OCXO can find on mouser or digikey mostly has a 5 or 6 pin layout, there is a pin Vref, not sure how to deal with that. Probably need extra circuits to provide that voltage. May be not a direct replacement on the DAC


----------



## Whitigir

demos said:


> I take off the cchd575 on the 004, put in a 950x, there is significant improvement on the 950x, WOW


Alright, I did just this, a little tricky as the 950x is much larger than the 575.  

The improvements are ? Seriously ! woW!!  Can’t believe how much it improved: soundstage, transparency, clarity, extensions, are all improved 

I wonder why lks004 don’t put in the 950X stock, but 575 instead.  The price differences are only $20 give or take ?


----------



## demos (Sep 5, 2018)

The 950x I try on my 004 is CVHD-950x, I getting this because this is cheaper and easier to buy at digikey. Want to try it out only. But turn out I am quite happy for how it sound on the 004 too, has instant improvement on  layering,  instrument separation more musical.




As expected after reflowed the unsoldered resistor leg, the clock voltage go back to normal, 3.28V on my dac.  I Guess I never getting this dac's original performance until the LT3042's Vset resistor solder join has been fixed. The solder to solder poor surface contact probably generate lots of noise which ruin the LT3042's very low noise capability and become a noise power source for the clock. After the fix, it even sound less digital on treble and sweeter. Background feel a bit cleaner and cleaner micro dynamic.


----------



## Whitigir (Sep 5, 2018)

Nice, you got the problem solved as I never heard lks004 to be digital or glary at all.

Anyways, what is the differences between cchd and CVHd ?

Found it:  CCHD has 25PPm -165 and -160 where as CVHD has 20PPm -166 and -162.  Doesn’t explain why cchd is more expensive


----------



## demos

CVHD is a Voltage Controlled clock,  CCHD is a fixed clock. It's for different application. The  20ppm on CVHD is for Absolute Pulling Range, which has a different meaning for the 25ppm on CCHD. CVHD Has a Voltage Control Pin which need 0~3.3V I just solder it to ground for 0V.


----------



## Whitigir

demos said:


> CVHD is a Voltage Controlled clock,  CCHD is a fixed clock. It's for different application. The  20ppm on CVHD is for Absolute Pulling Range, which has a different meaning for the 25ppm on CCHD. CVHD Has a Voltage Control Pin which need 0~3.3V I just solder it to ground for 0V.



Thanks for the clarification, I can see that voltage control pin being wired to ground there.


----------



## b0bb

demos said:


> The 950x I try on my 004 is CVHD-950x, I getting this because this is cheaper and easier to buy at digikey. Want to try it out only. But turn out I am quite happy for how it sound on the 004 too, has instant improvement on  layering,  instrument separation more musical.
> 
> 
> 
> ...



Looks like it is working, I would not worry, the poor performance was due to poor conductivity of a badly heated solder joint. The reflow fixes it..


----------



## Whitigir

b0bb said:


> The LKS uses the Amanero Combo384 USB to I2S board
> The datasheet contains the pinout of the module: http://www.amanero.com/drivers/combo384-D.pdf
> 
> The Tiger board is a derivative of the Amanero according to its website, suggest contacting the manufacturer for further assistance.



Has anyone tried to replace the DIYinHK Xmos in place of the Amanero yet ? I would love to do this


----------



## Bratsson

Hello.
What do you think.
Is the MH-DA003 modded with Sonic Imagery 994 and CCHD-950X  better than Gustard x20pro?


----------



## Whitigir

I don’t know about gustard  x20.  But all I can tell is that lks004 has a huge upgrade with good clock.  It is no longer in the same tier it used to be


----------



## Bratsson

Okay but the upgraded lks003 then?



Whitigir said:


> I don’t know about gustard  x20.  But all I can tell is that lks004 has a huge upgrade with good clock.  It is no longer in the same tier it used to be


----------



## Whitigir

Bratsson said:


> Okay but the upgraded lks003 then?


@b0bb already say and disclosed so much on 003 upgrades with clocks, you should use search functions and find out


----------



## Bratsson

Ok. I will have a nother look at it. 

Thanks




Whitigir said:


> @b0bb already say and disclosed so much on 003 upgrades with clocks, you should use search functions and find out


----------



## rafals

The original blue capacitor on the Amanero PSU is 0.1u. Why do you recommend to replace it with WIMA MKS2 10uF? (just asking)

Is there a complete list of changes to be made on the main LKS 003 PCB with BOM?


----------



## gto88

Selling my da003, if anyone is interested
https://www.head-fi.org/threads/l-k-s-audio-mh-da003-es9018-2-for-sale.908627/


----------



## mikeg2

b0bb said:


> Good to see you are getting the desired results.
> I also have the Schiit R2R Yggy and the modified LKS is equal to it and better than the Schiit in some areas.
> 
> It runs very warm on mine. The big heatsinks run about 45degC the smaller ones ones about 50degC.
> ...





Hello, 

I've replaced the diodes and voltage regulators. Unfortunately,  the heatsinks on the voltage regulators run very hot - especially the one on the right side - nearest to the side wall. The other 2 seem to be significantly cooler, but quite warm as well. The DAC turns itself off after a while - probably a kind of thermal protection. My voltage regulators were equipped with very small heatsink and thermal pads (the grey ones). I used those pads mounting the new regulators. The LKS heatsinks are quite big compared to the ones that came with the regulators, so something seems seriously off. 
As of the sound - I cannot really say anything yet if that changed anything. 
Please help - thanks in advance.


----------



## b0bb

mikeg2 said:


> Hello,
> 
> I've replaced the diodes and voltage regulators. Unfortunately,  the heatsinks on the voltage regulators run very hot - especially the one on the right side - nearest to the side wall. The other 2 seem to be significantly cooler, but quite warm as well. The DAC turns itself off after a while - probably a kind of thermal protection. My voltage regulators were equipped with very small heatsink and thermal pads (the grey ones). I used those pads mounting the new regulators. The LKS heatsinks are quite big compared to the ones that came with the regulators, so something seems seriously off.
> As of the sound - I cannot really say anything yet if that changed anything.
> Please help - thanks in advance.


Post photos of the mod you did. The original  LKS heatsinks must be reused otherwise the regulators will overheat.


----------



## mikeg2

b0bb said:


> Post photos of the mod you did. The original  LKS heatsinks must be reused otherwise the regulators will overheat.


Thank you Bobb for your response.
Here are the photos:











In your futher notes, I've found that for the new regulators the tantalum capacitors need to be used. They weren't listed initially for the mods, hence they are not present in my unit. Can this be the reason of overheating?


----------



## b0bb

mikeg2 said:


> Thank you Bobb for your response.
> Here are the photos:
> 
> 
> ...



Your photos did not attach properly.

The tantalum caps help with stability of the regulator.
Overheating may be due to oscillation, but I would double check the heatsinking arangements before doing this.


----------



## fmzip (Dec 11, 2020)

Great stuff b0bb


----------

