[Gilberto 62]

I bought it at Audio Clear Components in Germany, through eBay. Now I will have to repackage it and send it back to Germany. Hahaha...! I laugh not to cry ... What a mess. Thank you very much for your patience and time. A greeting.

 

[hpsxrb]

I bought it at Audio Clear Components in Germany, through eBay. Now I will have to repackage it and send it back to Germany. Hahaha...! I laugh not to cry ... What a mess. Thank you very much for your patience and time. A greeting.

You do not have to thank, it was a pleasure to help but unfortunately we were not successful.

 

[Gilberto 62]

Well, I think it's a good idea to explain my recent odyssey with the LKS a little. A few days ago this dac came to my house, which I had been following the reviews for a long time and all the opinions of users (.... where they really tell the truth ...) and I thought, this dac deserves A good usb cable, so I bought the Audioquest Diamond 5 meters for 1500 euros. Well, two days ago I started to connect everything and start its configuration and ... surprise ...! everything malfunctioned, cuts, stops, phantom noises, crunches, sssshhhhhhhhhh, fffffffuuuuuuuuhhhh, etc, etc. After trying a million configurations with Foobar and JRiver and asking for help here in the forum, (.... thanks "b0bb", thanks "Whitigir", thanks "hpsxrb", thanks to all of you in general ...) and a desperate trial-and-error race, trial and error, already embarrassed to think how it could be that everyone succeeds and I don't, being my first contact with the dac world, already believing myself totally incapable, in the end, fed up with everything and as the patient and generous "hpsxrb" insinuated to me, I thought that the problem was in the dac or its Amanero board. Having decided to return the dac to Germany for inspection and fed up and tired of everything, it occurred to me to try the stock cable, the one that comes in the box with the dac. And miracle ...! Yes, there was the damn problem, in the garbage of Audioquest Diamond cable of 1500 euros.
"hpsxrb", he tells me that it could be due to the length of the cable, 5 meters, but that is the distance between my htpc and the dac, well, a little less. But gentlemen, how is it possible that a 1500 euro cable does not work ...? 5 meters is a lot ...? so why do they sell them ...?
It was necessary to write this for first, to thank for your support and second, for that of ... "the esoteric world of cables ..."

 

[littlexx26]

Well, now we're getting into less outrageous territory. The SR Orange fuses are receiving complaints all over the internet for blowing on first or second power on after installation at values even 50% higher than rated value. What value SR Orange did you go with for the LKS?

Out of curiosity, have you compared the various SR fuses?

Thanks!

I follow the stock value 3.15A. I have 14 SR Orange fuses with different specs including UK plug 13A for mains and none of them has a single problem. I did not compare to older SR fuses because I just started playing fuses last year and sure I wouldn't buy Blue or Black or Red because they are too old. But I can tell in Hong Kong here people who have older SR fuses said Zero is much superior than them.

 

[littlexx26]

I'll paste one more picture because you asked. I had to re-open the unit.

All are high quality caps do they sell the board individually?

 

[hpsxrb]

LKS MODIFICATIONS

I have done a significantly more amount of work than most people would do. However, it all adds up in the end. With all the upgrades, this DAC no longer resembles stock. The resolution and attack are amazing. High frequency detail is significantly improved and much more realistic. Bass is significantly stronger (think “punch you in the chest” type of bass). This DAC is now absolutely beautiful to listen to.

This is the work I have done:

A/C input
--------------------
- Furutech gold IEC => Upgraded to Furutech Rhodium IEC
- Fuse => Upgraded to Furutech Rhodium 3.15A (not available anymore)
- Transformer Secondary wires => twisted like everyone else
- Rectifier Diodes => All 24 diodes upgraded to 8A Vishay Schottky Diodes (VS-8TQ100-M3)


Digital Power Supply
--------------------
- 4x6800uf Gold Tune caps => Initially I upgraded these to 4x10,000uf Nichicon KW. I can’t remember where I read this, but I’ve read that Gold Tune are not as tight sounding and somewhat laid back. Anyways, I wanted to boost the capacitance, so I used KW caps. Later, I decided to go and upgrade to all Mundorf. I used a Mundorf 22,000uf 25V for the left most largest cap. I used Mundorf 10,000uf 25V for the 3 remaining. I did some measurements and these caps are only seeing 9V DC after the rectifier diodes, so the 25V Mundorf caps are totally safe and provide much larger capacitance. They are also 125 degree caps. I soldered Vishay 0.1uf MKP film caps to the leads underneath the board because they wouldn’t fit in the spaces between these large caps.
- 390uf post-regulator caps => Upgraded to 470uf Nichicon FG.
- 0.1uf MKP post-regulator => Upgraded to Vishay 0.1uf MKP (BFC241641004) except for one spot where I had to use a smaller WIMA 0.1uf MKP.
- LM317 regulators => I thought about upgrading these to the Sparkos SS1117 discrete regulators, but the Sparkos are internally limited at 1A. The LM317 allow up to 1.5A of current, and we know the DAC chips love the current. I don’t think I’m getting any less of performance at this point. Upgrading to Sparkos would require tweaking of the SMD resistors in front of the regulators.


Digital Circuits
--------------------
- Replaced the input coupling caps (big 0.1uf WIMA) on the S/PDIF inputs with straight wire (Ric Shultz trick). I used Neotech 20awg solid-core OCC copper that has been stripped.
- 270uf Polymer caps => All these were upgraded to Nichicon 330uf polymer. It’s not much, but every little bit helps! The stock 270uf caps are actually very good, so you can skip this part if you want. Make sure you re-solder those film caps on the bottom leads.
- 100uf Polymer caps => I left these alone because the stock Panasonic SEPC had such a great ESR (8 mohm). I couldn’t beat that.
- 0.1uf film caps => replaced these with Vishay 0.1uf MKP
- Crystek 575 => I did several clock tests before I decided on the Accusilicon AS318-B-100 (clock comments are in following post). I soldered a small 0.01uf film cap across the GRND/POWER pins on the bottom side of the board. For testing purposes, Mil-Max has a nice 14-pin socket with only 4 pins loaded so that you don’t have to melt out those other pins (digikey ED90428-ND). For final clock, I remove this socket and soldered the clock directly in.



Analog Power Supply
--------------------
- 2x4700uf Mundorf => Upgraded these to 2x10,000uf 40V Mundorf
- 2x1000uf post regulator => Upgraded to 2x1000uf Nichicon FG
- 220pf regulator MKP => Upgraded to 220pf Kemet PFR film-on-foil caps
- 0.1uf film caps => Upgraded to 0.1uf Vishay MKP


Analog I/V section
--------------------
- 22uf MUSE caps => Upgraded to 22uf + 47uf Nichicon FG. The 47uf caps used the hole for 0.1uf film caps. I soldered WIMA 0.1uf MKP to the leads underneath the board. For many years, I thought Nichicon MUSE were the best caps to use. However, about a year ago I did some critical comparisons for the heck of it and found that FG (Fine Gold) actually sounded better. The MUSE caps are nice and very high resolution, but they have a little bit of glare in the upper mids/highs. The FG caps actually sound much more natural and realistic and they have excellent high frequency response! I increase the capacitance for each discrete section. I found that having a bit more capacitance here helps with bass/midbass punch and strength. You definitely do not want to starve these discrete Class A circuits!
- 220pf MKP caps => Upgraded to 220pf Kemet PFR film-on-foil caps. These are the 3 caps in the middle if the discrete circuit (on earlier models, these are the silver-mica caps) I have found that these film-on-foil are superior to any MKP. However, they are only available in small values (up to 2200pf picofarad).
- 2200pf film caps => Upgraded to 2200pf Kemet PFR. These are the two inline rows of polyester caps above the circuit.
- 61.8 ohm resistors => Upgraded to Vishay CPF3 3-watt 61.9 ohm resistors. Like many have recommended, I could have gotten the TX2575-3 z-Foil resistors, but I didn’t want to deal with the lead time and $70 per resistor. In past projects, I have found that a higher wattage resistor actually is more transparent and provide better response. I learned this when comparing a .5w resistor to a 1w resistor in a op amp negative feedback circuit. The CPF3 are only $3.25 each (mouser 71-CPF361R900BEE14). I think they give excellent results! They are long and have to be soldered into the extended holes. These resistors have excellent specs at 0.1% tolerance and Temperature Coefficient of 25PPM/C (we all know this section likes to heat up). There are resistors that have lower PPM specs, but they are generally a much higher resistance. This was the best resistor I found between Digikey/Mouser for this application.

Can you please tell me the part number of the 220pf Kemet PFR film-on-foil caps in "Mouser". Thank you.

 

[AuxInput]

Can you please tell me the part number of the 220pf Kemet PFR film-on-foil caps in "Mouser". Thank you.

Kemet PFR 220pf
Mouser: 80-PFR5221J63J11L4
Digikey: 399-7684-ND

Kemet PFR 2200pf
Mouser: 80-PFR5222J63J11L4
Digikey: 399-7680-ND


Standby on some of my part recommendations. I am removing my FG capacitors and switching back to Nichicon MUSE KZ. The FG were very good, but do not have quite the resolution of the KZ.

 

[hpsxrb]

AuxInput:
"Standby on some of my part recommendations. I am removing my FG capacitors and switching back to Nichicon MUSE KZ. The FG were very good, but do not have quite the resolution of the KZ."

This change concerns:
1 - Digital Power Supply post-regulator cap (470uf Nichicon FG) ?
2 - Analog I / V section (22uF + 47uF Nichicon FG)?

What is the voltage of the CAP in Analog I / V, section because of the size (I have not yet opened the DAC) ?
Thank you

 

[Gilberto 62]

Hello everyone. Well, I'm enjoying this, my first dac, because until now, I was using the dac from my pc's sound card and, well, this is something else. I had problems with the Audioquest Diamond cabel that I bought and, while my store brings me another, I am using the stock cable.
I keep reading, admired for your knowledge and experience in changing some parts of the LKS to get better SQ results with your hardware updates. But, those of us who would also like to do all of this but we don't have the knowledge, tools, or time, is there somewhere or someone you know who can do all of that ...? If someone wants to give me their point of view, it will be appreciated.

 

[AuxInput]

AuxInput:
"Standby on some of my part recommendations. I am removing my FG capacitors and switching back to Nichicon MUSE KZ. The FG were very good, but do not have quite the resolution of the KZ."

This change concerns:
1 - Digital Power Supply post-regulator cap (470uf Nichicon FG) ?
2 - Analog I / V section (22uF + 47uF Nichicon FG)?

What is the voltage of the CAP in Analog I / V, section because of the size (I have not yet opened the DAC) ?
Thank you

The voltage of the stock caps in the Analog I/V section were 50V. I just continued to use 50V. I did some brief tests and I think the analog power supply is producing +/-15V DC, so 50V caps are a lot higher than needed. That being said, the KZ caps are only available in 25V and 50V, and it's a know fact that the 50V version sounds better. The stock 22uf caps were just final power supply filters to provide faster voltage/current response for the I/V circuit. The FG caps are nice, but are just too soft in the high frequencies (I recently discovered this characteristic). So, Nichicon FG are not recommended here unless you want a warmer/duller sound. I'm going back to MUSE KZ caps, but using 100uf. Please standby for a few days on final components.

As far as the digital power supply post regulator caps, it's totally fine to bump them up a little bit. The purpose of these caps is to provide faster current "on tap" when the circuits demand them before the regulator can start flowing current through to restore the voltage. Once again, FG is not fast enough for this.

 

[b0bb]

The voltage of the stock caps in the Analog I/V section were 50V. I just continued to use 50V. I did some brief tests and I think the analog power supply is producing +/-15V DC, so 50V caps are a lot higher than needed. That being said, the KZ caps are only available in 25V and 50V, and it's a know fact that the 50V version sounds better. The stock 22uf caps were just final power supply filters to provide faster voltage/current response for the I/V circuit. The FG caps are nice, but are just too soft in the high frequencies (I recently discovered this characteristic). So, Nichicon FG are not recommended here unless you want a warmer/duller sound. I'm going back to MUSE KZ caps, but using 100uf. Please standby for a few days on final components.

As far as the digital power supply post regulator caps, it's totally fine to bump them up a little bit. The purpose of these caps is to provide faster current "on tap" when the circuits demand them before the regulator can start flowing current through to restore the voltage. Once again, FG is not fast enough for this.

The bypass caps you changed have a critical role in the DAC.
At 384kHz or DSD512 sampling, there will be a lot of transient energy at 24.5MHz, 49MHz and 12.3MHz around the I/V power feed
The responsibility to dampen this and maintain near DC conditions falls onto these caps.

Capacitors however have a limited frequency range in which they act as capacitors.

Here are plots some real numbers for a 10uF cap
The bigger the value the lower the transition frequency, a 100uF cap will transition around 100kHz

Smaller value caps have a higher transition frequency
If a big cap is paired with a smaller cap it covers a much wider range.

This is the reason why LKS paired a big electrolytic cap with a smaller film cap.

The output stage runs in Class-A, the load current is more or less constant, adding an extra electrolytic cap is not going to improve filtering.
The electrolytics are effectively non functional above 1MHz

It will upset the existing balance between the electrolytic and film cap .
The film cap is the one doing most of the work to get rid of the high frequency noise

One of the symptoms of this condition is a dull sounding DAC as you have noted.
If you want a better quality small bypass cap, replace the metallized polyester with a polypropylene cap.
Better yet add a small (100pf - 1nF) X7R or better monolithic ceramic cap in parallel to the film cap.

The best high frequency dielectric material is glass, I have used Corning CGW caps in the past, they are the go to caps if you want to improve bass slam.

The graph came from a Murata application note.
Link below has more info
https://article.murata.com/en-us/article/impedance-esr-frequency-characteristics-in-capacitors

 

[AuxInput]

The bypass caps you changed have a critical role in the DAC.
At 384kHz or DSD512 sampling, there will be a lot of transient energy at 24.5MHz, 49MHz and 12.3MHz around the I/V power feed
The responsibility to dampen this and maintain near DC conditions falls onto these caps.

Capacitors however have a limited frequency range in which they act as capacitors.

Here are plots some real numbers for a 10uF cap
The bigger the value the lower the transition frequency, a 100uF cap will transition around 100kHz

Smaller value caps have a higher transition frequency
If a big cap is paired with a smaller cap it covers a much wider range.

This is the reason why LKS paired a big electrolytic cap with a smaller film cap.

The output stage runs in Class-A, the load current is more or less constant, adding an extra electrolytic cap is not going to improve filtering.
The electrolytics are effectively non functional above 1MHz

It will upset the existing balance between the electrolytic and film cap .
The film cap is the one doing most of the work to get rid of the high frequency noise

One of the symptoms of this condition is a dull sounding DAC as you have noted.
If you want a better quality small bypass cap, replace the metallized polyester with a polypropylene cap.
Better yet add a small (100pf - 1nF) X7R or better monolithic ceramic cap in parallel to the film cap.

The best high frequency dielectric material is glass, I have used Corning CGW caps in the past, they are the go to caps if you want to improve bass slam.

First, I am not a senior EE guy. However, I absolutely know the requirement of a small film cap along with the electrolytic in this scenario. I have heard and experienced the effect of an electrolytic's inability to filter high frequency response. I placed in two FG caps here -- the 47uf and 22uf are operating in parallel to provide a larger reservoir of immediate current for these I/V circuits. However, it seems that you have completely missed one of my statements that I have soldered a 0.1uf WIMA MKP (metallized polypropylene) to the leads of these capacitors UNDERNEATH the board. So the film cap is still there, it's just not visible.

All of my R&D and testing has been done through listening tests and not necessarily choosing components from "engineering math". I did not necessarily mean that the high frequencies were gone and the sound was completely dull. The high frequencies are there with these FG caps and the sound is very clean. The sound is just warm and not as "snappy" and exciting as with KZ caps, which could make the sound just a very tiny bit flat. This is something I just recently figured out because I do have several other devices loaded with FG caps and they all carry the same sonic signature.

I don't know if you realize, but the original version of the LKS had 47uf FG caps. Now it has 22uf MUSE KZ caps. These 22uf caps are the largest KZ caps that can be placed in this position and still have space to put in that polyester film cap FROM THE TOP. Regarding your comment on bass slam, these 22+47 FG caps in parallel provide enormous bass slam.

Now let's move on to sizing. You may think that a small 22uf cap may be sufficient here from engineering math and possibly from scope readings. However, my listening experiences have told me that undersizing this cap in a circuit that is high current Class A can actually starve the circuit a little bit. The result is a lack of full bass and sound that is somewhat lean and can be forward in the upper mids or even bright/thin. Increasing the size of local electrolytic caps for filtering increase the amount of "immediate current on top". This provide much fuller stronger bass and reduces the "starving" effect which smooths out mids and highs. This is especially critical on high current Class A circuits. It doesn't matter if you have 20,000uf in the main power supply, if you have small filter caps next the I/V circuit, you are still going to starve it. Basic monolithic op amps do not suffer as badly from this effect, but good local filtering/reservoir will always help.

 

[oldearwax]

... is there somewhere or someone you know who can do all of that ...? ...

Ric Schultz
http://tweakaudio.com/EVS-2/LKS_Mods.html
offers mod service.
The modifications mentioned in this forum is a lot more extensive/intensive than Ric's, IMHO.

 

[b0bb]

First, I am not a senior EE guy. However, I absolutely know the requirement of a small film cap along with the electrolytic in this scenario. I have heard and experienced the effect of an electrolytic's inability to filter high frequency response. I placed in two FG caps here -- the 47uf and 22uf are operating in parallel to provide a larger reservoir of immediate current for these I/V circuits. However, it seems that you have completely missed one of my statements that I have soldered a 0.1uf WIMA MKP (metallized polypropylene) to the leads of these capacitors UNDERNEATH the board. So the film cap is still there, it's just not visible.

That is the reason I called the thing out, very easy to miss the description given the photo.
I had to read your description more than once.

This is for the benefit of those trying to replicate the work you did.

I don't know if you realize, but the original version of the LKS had 47uf FG caps. Now it has 22uf MUSE KZ caps.

I have the original with the 47uF FGs, the 22uF KZ are a step down, KZs do not do well in mixed analog and digital bypass roles.

LKS actually bumped down the output stage bias current on the later 004 models to get away with using smaller bypass components and to address complaints of overheating.

 

[b0bb]

Ric Schultz
http://tweakaudio.com/EVS-2/LKS_Mods.html
offers mod service.
The modifications mentioned in this forum is a lot more extensive/intensive than Ric's, IMHO.

There is more of this in the forum for the 004's predecessor for those looking for mod ideas that can be applied to the 004.
https://www.head-fi.org/threads/lks-audio-mh-da003.745032/page-3

A few pictures of the work over the years in one place.

Low noise schottky diodes for the power supplies, Schottky diodes do not produce the turn off spike when it stops conducting this stops the spray of RF noise.
The kinks in the scope trace show the ugly turn off behavior of a conventional diode, this is the one in my 004. (It is on my TODO list to fix...)
The fuzz at the transtion is the RF ringing.

Schottky diodes however leak a lot of reverse current about 10x worse than the conventional diodes, the ones show below are very low leakage about the same as a conventional diode

Vishay TX2575 metal foil resistors for the current to voltage (I/V) converter.
This is the heart of the digital to analog conversion

The the 004 requires the resistors to be doubled up and a value changed to the one the 004 is using.
WIMA film foil polypropylene to bypass the caps on the other side of the boad
The cream coloured component at the near top of the WIMA is a C0G high frequency bypass ceramic cap

TI TPS 7A47 RF low dropout regulator to replace the LM317 that LKS is using for the input interface circuitry.
This regulator is designed for digital circuits
The wiring mess is no longer necessary in the current versions of the regulator, this was from a few years ago.
This is a more complicated mod that requires circuit change.
The is requires the output cap soldered in, this is the circle footprint in front of the regulator.

The purple caps are the original Sanyo OSCONs organic polymer cap.
Nichicon FPcap comes close. Modern day OSCONs are worse than the FPCap.
They are like getting hard to find, grab them on Ebay if they show up.

Polystyrene film foil caps are an alternative to polypropylene, it was a good complement to the ES9018.
These we matched to better than 1%
The caps are the ones in the transparent housing, the horizontal cap with the transparent yellow casing on bottom left is also polystyrene except that the electrode material is copper foil instead of aluminum foil.

The bright yellow blob is the common mode reference divider bypass cap.
ESS uses a common mode reference divider for all its DAC chips including the 004.

This is a 100uF ultra low leakage solid tantalum. This is on my TODO list for the 004.

The black rectangular box on the extreme left with the CGW TY05 marking is the Corning glass bypass capacitor