Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 4, 2019 8:06:37 GMT
Hi Martin
I would like to make a suggestion first, obtain some scrap circuit boards and practice first before attempting this, hot air is far more difficult to keep away from surrounding components, also for HA to work effectively you will need to use a pre heater on the underside of the board (around 140-180C for a specific time) as this cuts down on the amount of time you have the HA nozzle near the component to be removed. It does make a big difference to the result imho
|
|
|
Post by MartinT on Apr 4, 2019 9:03:30 GMT
Thanks, Tony. I have plenty of scrap circuit boards at work so shall practice away. I've watched several YouTube videos on how to do it which have helped.
|
|
|
Post by MartinT on Apr 6, 2019 17:10:48 GMT
Taking the lead from the Head-Fi LKS thread (an awesome source of information running to 135 pages currently), it was proposed by one chap that the two exposed toroidal transformers could do with some shielding to keep RFI noise (rather than mains hum) away from the delicate digital clock and circuits. Some manufacturers using the ES9038 chipset have shielding separating the transfomer(s) while others haven't. I was going to wait for the crystal upgrade but that wouldn't tell me what had had which effect so I set to it today. This is the stock layout... The Head-Fi member built a copper 'wall' between the transformers, running from the back to the front with cutouts for the cables. I decided to copy the principle but do it more simply so that I could easily remove it should it not work. I used thin self-adhesive copper foil shielding (doubled-up) and some more of my cotton-covered copper wire. Strengthening the foil with card worked a treat and I did each transformer separately, making cutouts for the cables. I then grounded each shield with the cotton-covered wire to the same grounding tag connecting mains earth to the chassis. It ain't pretty but I wanted to hear the results and, as I said, it can be easily removed. You can just see the grounding tag to the right of the right-hand transformer. The result surprised me as I really didn't expect to hear much if anything at all. I played the same music as before and in each case the soundstage was better focussed and the background became even quieter (darker, blacker, whatever your prefererence). There is just a smidgen more ease and flow to the music. Pretty good for less than a tenner's worth of materials.
|
|
|
Post by John on Apr 6, 2019 17:15:06 GMT
Good result
|
|
|
Post by MartinT on Apr 13, 2019 16:12:26 GMT
The story so far: I bought the LKS as basically a well built and well specified modding project, in the same way as my car. Great base performance, better potential, easily yielded with a few mods.
Up to now, I'd removed the USB module as being of no use to me and added the copper shielding as above. I'd also put an SR Red fuse in the rear IEC socket. Next on the list was the crystal and I thought I'd be able to do that job myself. It turned out to be an utter bastard. Not only was the original a pig to remove (I think it had been spot glued in place before soldering) but the Crystek replacement was larger with solder pads underneath and required a hot air gun. Cutting a long and painful story short, I could not get it to work and called in the services of @tonyc . He has soldering equipment I can only dream of, but even he could not remove the replacement crystal without destroying it. Two damaged crystals later, and a cleaned up board, he ordered an interim crystal from Farnell and had me up and running a couple of days later.
What he did do, in addition to getting a perfectly decent Silicon Labs crystal in and working, was to breath on the sensitive power supply feeding the oscillator with some trick capacitors and rectifiers. LKS use a goodly selection of excellent Mundorfs, Nichicons, Clarity, Wimas etc. but there is further scope for improvement. The outcome of that work is that a seemingly inferior crystal (100fs jitter versus 82fs in the original) proves yet again that specs do not tell the whole story. It's clearly working better and my LKS is sounding fabulous. The overall effect is of greater depth, air and space without losing the knockout attack that the LKS is so good at.
So, a failed mod and a reasonable amount of humble pie later, I have a superbly performing DAC with a sound quality that has all of the 3D soundstaging of my tricked up SEG but with a whole new level of detail, attack and bass slam.
|
|
|
Post by Firebottle on Apr 14, 2019 6:59:45 GMT
'The result so far' is sounding rather good Martin. Most surface mount parts are glued first so they don't float away when the solder is reflowed.
|
|
|
Post by petea on Apr 14, 2019 8:39:56 GMT
Would acetone damage the board? This is often good for releasing isocyanate-based adhesives.
|
|
|
Post by MartinT on Apr 14, 2019 10:07:43 GMT
Pete - I'm not sure about acetone, we used isopropyl alcohol for the cleanup and to remove excess flux.
Alan - yes and trying to remove something like a crystal with heat means that the can ultimately comes off and you are left with a tiny circuit board that won't budge!
|
|
|
Post by Firebottle on Apr 15, 2019 7:06:56 GMT
Alan - yes and trying to remove something like a crystal with heat means that the can ultimately comes off and you are left with a tiny circuit board that won't budge! Sorry Martin but I find that quite funny, I bet a phrase like 'Oh bu££er' came to mind
|
|
|
Post by MartinT on Apr 15, 2019 7:09:37 GMT
My phrase was similar but possibly more colourful!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 15, 2019 7:55:04 GMT
To be fair to Martin only the clock was affected, but judicious use of IPA and an acid brush things came back to normal. The LKS board is a solid 5mm + thick!
|
|
|
Post by MartinT on Jun 21, 2019 20:17:31 GMT
After a very nice couple of months spent with the temporary replacement crystal oscillator from TXC, which sounded much better than the Crystek 575 fitted as stock, I finally had the full Coherent ultra low phase crystal oscillator module installed in the LKS today. It took some time to find the ideal voltage rail, but we found a 9V rail powering the digital circuits which could provide the 100mA required. The module has onboard regulation so the exact voltage is immaterial. The module itself was positioned right next to the two ESS 9038 Sabre DACs (shown with heatsinks) with the clock signal going to the pads vacated by the outgoing crystal. We had taken a scope capture of the 100MHz clock from the TXC, which was a fairly distorted sinewave with lots of harmonics. The clock from the Coherent module looked like a perfect sinewave and spectral analysis showed excellent purity and a low -80dB noise floor. Things looked promising, especially after a test run on Tony's system. I've had it running in my system for a few hours now, giving time for the LKS to warm up again and starting the burn-in process for the module, and I'm very pleased with what I'm hearing. Over the TXC, there is more of everything that the latter crystal had revealed: a well developed wide and deep soundstage, startling fine detail, no harshness whatsoever and very good dynamics. Overall, vividness takes another step up towards reality. Over the Crystek, the LKS really shows what the superb dual ESS 9038 DACs are capable of. Huge detail, propulsive rhythms, vivid and palpable performances, wonderful voice reproduction. The Coherent module will suit a wide variety of DACs and players and is well worth the cost of having it installed.
|
|
|
Post by MartinT on Jun 21, 2019 21:49:21 GMT
You only have to look back to your review of the Meicord which you bought from me but put the link in to meicords homepage. When I reviewed MCRU-made cables, I linked to MCRU. When I reviewed the MeiCord cable, I linked to MeiCord. I usually talk about the manufacturer, not the supplier.
|
|
|
Post by brettj on Jun 22, 2019 7:08:59 GMT
I have done with my LKS DAC now if anyone wants to offer me a good price for it. How much are you wanting for the LKS?
|
|
allhifi
Rank: Starter
Hello from Canada ...
Posts: 2
|
Post by allhifi on Oct 19, 2019 2:12:34 GMT
Hi Martin: Excellent product overview -very insightful. Thanks for sharing.
Indeed, there is considerable Internet 'chat/talk' on this very nicely built -and sounding- DAC.
Your listening impressions were very insightful.
It's been about two years now since owning a similar small, niche Chinese company DAC in the Gustard line; X20PRO w/USB DAC.
Gustard recently introduced their dual 9038 (ESS) DAC, the 'X-26' -also to wonderful reviews. On "sale" (from Shenzen), it's priced at $1,169. (USD), $1,269 with USB. Since I have had a great experience with the X-20PRO (and their U-12 spdif converter), the X-26 may be my next imminent DAC purchase.
I note that the 9038PRO (and 9028PRO?) ESS chip architecture has multiple 'pins' dedicated to separate power supply traces. That, and the shift to far greater power/voltage/current swings signal (to me) ESS's serious foray into ultra premium DAC chips based solely on performance as opposed to greater power consumption efficiency.
Should I get my 'hands' on a X-26 (purchase one), I'd be more than happy to share my observations.
Btw Martin, I'm pleased to note tat you are lowering your DAC with an AC 're-generator. I've advocated (for the past twenty years) of the immense gains offered when powering 'Digital' components via AC Re-generation (i.e. PS Audio Power Plant's,) or alternately, a Balanced/Symmetrical AC Power 'Supply' /"Conditioner" such as that from 'Equi=tech'.
Thanks again for sharing,
pj
|
|
|
Post by MartinT on Oct 19, 2019 9:15:01 GMT
Thanks, Pj. I did look at the Gustard X26 but it was so new there was no information about it at all. However, Gustard do have a good following like LKS. I have openly admitted that I bought the LKS blind and I don't regret it at all as it suits my system and my musical preferences very well. The stock crystal can be rather aggressive but that is remedied by replacement. The ES9038 chipset is remarkable in its ability to dig huge amounts of detail and ambience from the digital stream, and getting more from my music is very satisfying. I never took the easy path with a 'nice' choice, I've always gone for as close to the music as I can get. The system needed some attention to rebalance for the remarkable levels of resolution but that's all sorted now.
The P10 regenerator (and a Premier before that and a P300 before that) has been an essential part of my system. I pay a great deal of attention to power treatment and the payoff is a very low noise floor and stunning dynamic range.
Do let us know what you decide to go with.
|
|
|
Post by MartinT on Feb 14, 2021 14:18:30 GMT
It's been a long time since I updated this thread, but today I performed the last of the mods I intended for the LKS. Sometimes it's just having the right mindset to do these things: I've had the parts for a while but was worried that I might trash my lovely DAC in the process. Today, I thought, just get on with it as you know you want to do it! These mods are quite fundamental to how well the DAC converts the digitally processed signal into an analogue output. I replaced the I/V resistors (the ones which help convert the ES9038 current output into voltage), and the V com capacitors. Below, you can see that the four original 61.9Ω 0.5W I/V resistors (much smaller ones mounted under the PCB) have been replaced by Vishay CPF3 61.9Ω 3W resistors mounted on top next to the capacitors (the brown ones). There is little room underneath with the heat spreader bar so I thought they would be better mounted on top. Secondly, the two large electrolytic V com capacitors have been replaced by two low leakage 100uF 10V tantalums (orange blobs). I've only just reassembled it all and got it hooked up to the system, so it's early days and the new components will need some burning in. However, right from the off I can tell that this is going to be the final icing on the cake. There is no overall change in balance or presentation, or even detail, but there is a clarification of the image, a reduction in slight blurring when the mix gets busy, and further tightening of the bass (the effect of the V com caps). There is also the removal of the tiniest 'sheen' to the proceedings, giving further insight into how strings are plucked, enunciation of vocals etc. It's a small thing, noticeable on some vocals but not others. I really like this DAC, it suits my preference for how music should be portrayed. I find myself listening more these days, rather than less, indicating that the essentials are all in place. My thanks go to the guys at Head-Fi who have written reams about the LKS (220 pages so far), and particularly b0bb there, who has suggested many of the mods performed here (although Tony's Coherent clock may be unique to mine).
|
|
|
Post by MikeMusic on Feb 14, 2021 17:49:00 GMT
I so often put things off due mostly to apprehension. Planned well enough is usually a doddle
|
|
|
Post by John on Feb 14, 2021 19:30:37 GMT
Good work Martin Any other plans for the future with regards to improving the DAC
|
|
|
Post by MartinT on Feb 14, 2021 20:15:56 GMT
Never say never, John, but I've done all I set out to do with it. It's performing at a very high level and I doubt I could wring out much more from it without fundamentally changing it.
It's interesting that LKS (now Musetec) have released its successor, the MH-DA005, at a much increased $3,300 price point. That shows what it took to improve on the 004.
|
|