[piaseczek]

Crystek 950x and Vishay naked foil.

 

[MartinWT]

Thanks. What is the value of Vishay resistor required?

 

[Monolithic]

Thanks. What is the value of Vishay resistor required?

It’s dependent on which board version you have. It’s best to remove the board and inspect first. Resistors are on the bottom of the board.

I would also determine the IV peak current as b0bb has outlined in this thread before removing the board.

See post #1743
https://www.head-fi.org/threads/l-k...s-double-impact.840938/page-117#post-14689266

 

[wersuss]

Crystek 950x and Vishay naked foil.

The 950X , should it be same as stock 100mhz or mhz of oscillator doesn't matter?
The one i found on ebay is 122.88 mhz.
https://www.ebay.com/itm/1pcs-CVHD-...h=item3d7383d75c:g:U6QAAOSwQZVcG4sf:rk:1:pf:0

 

[b0bb]

B0bb,
Could you help please and measure the resistance value in your DAC?

Maybe in my case high value of the resistance is a result of a non isolated heat sink underneath a board, the transistors are not isolated from a chassis. Make sense?

Signal ground on the rca connectors and chassis ground on the power inlet not connected on my Gen1 DAC

 

[b0bb]

The 950X , should it be same as stock 100mhz or mhz of oscillator doesn't matter?
The one i found on ebay is 122.88 mhz.
https://www.ebay.com/itm/1pcs-CVHD-...h=item3d7383d75c:g:U6QAAOSwQZVcG4sf:rk:1:pf:0

Stick to the 100Mhz, there are internal frequency pre-scaler registers on the DAC that have to re-adjusted if you change the master clock frequency
VCXOs have a voltage input that can change the output frequency, you will have to do extra work to negate any noise pickup on the VCXO input to prevent the oscillator output from drifting.

 

[b0bb]

@Whitigir

PS: ...the IEC backplate is now of course on the DC side!

....like this example

Replace the IEC inlet backplate, several vendors sell them of the SU-1
https://www.ghentaudio.com/part/dc99.html

 

[piaseczek]

Signal ground on the rca connectors and chassis ground on the power inlet not connected on my Gen1 DAC

Thank you b0bb. Do you think that something wrong might be with my DAC?

Additionally I have a ground loop when I connect with RCAs the 004 DAC to my power amplifier and that makes me wonder if everything is ok.
Both devices are equipped with the PEs. There is no problem with the ground loop when I use XLRs.

 

[piaseczek]

Thanks. What is the value of Vishay resistor required?

In my DAC (the second iteration with the heat sink) the value of the IV resistors are the same as on b0bb's one.
I think that everything above 0.5 is fine. Foil resistors in the IV make a big improvement in sound.

 

[piaseczek]

0.5W...

 

[b0bb]

0.5W...

Double that, you must increase that number as there is no active airflow in the case, this is called thermal de-rating.
Use a 1W rated resistor

 

[Paul Staples]

Replace the IEC inlet backplate, several vendors sell them of the SU-1
https://www.ghentaudio.com/part/dc99.html

thanks!

 

[piaseczek]

Double that, you must increase that number as there is no active airflow in the case, this is called thermal de-rating.
Use a 1W rated resistor

The original one was with a rated power of 0.5W, but I believe you that a 1W would be a better choice

 

[wersuss]

Double that, you must increase that number as there is no active airflow in the case, this is called thermal de-rating.
Use a 1W rated resistor

The original one was with a rated power of 0.5W, but I believe you that a 1W would be a better choice

Which part for vishay foil resistor?

 

[b0bb]

Which part for vishay foil resistor?

TX2575-2 68.1 ohm on a Gen1.
If you have a Gen 2 (the one with the low powered XO regulator) it is 62ohms

This is a 2 module resistor that can dissipate up to 0.8W with no air flow and 1.2W with some air flow.

https://www.head-fi.org/threads/l-k...s-double-impact.840938/page-117#post-14689266

Double check your unit to determine the exact one.

These are made to order by Texas Components.

This the best grade Z-foil with a non inductive layout