[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.

 

[Carlo7]

Bobb, have you or anyone compared Ares Amanaro dac to Lks 004 ? Not enough posts on this one.

Thanks carlo7

 

[b0bb]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

I don’t think pulsar sell 100M anymore right ?

They say not plan to restock the 100m for now