so! after many rounds of troubleshooting over 2 weeks I finally got a solution to constant crackling issues.

Background: I had upgraded my asio driver to 1.61, device firmware to the 2.0 one where u can use it as a standalone mixer. and i noticed there's jus this crackling all the time, it's super noticeable when i play a sample track from traktor (a1 909 kick solo) and just filter the highs out, the crackling is there all the time even when it's just one track playing. Long story short I finally found that reverting the device firmware back to the old one makes audio streaming in traktor purrrfect. u can either use the one that comes with 1.52 asio driver or the one found here , both achieved same results in my case. (Although in the page on how to reset your firmware back to the original there is an extra step of resetting the midi firmware with another program, I wonder if the midi firmware gets automatically updated with the 2.0 firmware...??)

But now I have a problem, I use the vci400 as a audio interface for day to day windows laptop usage also and with this old firmware none of my windows applications have sound! Although in the playback devices window (when you right click on the speaker icon in the taskbar) it shows that there is audio playing. The LED on the VCI-400 does not light up. I update the asio firmware back to 1.61 and it still has the same issue, with traktor audio still working fine, again proving that its the device firmware that is the problem in my crackling issue.

I've also sent an email to vestax at to ask them about this issue. Posting here in case they dont reply, since they never did with my previous email.

*I'm on win7 x64, asus k55vj laptop.
*mine is the original vci-400, not the ean golden edition