Best tubes for Audio Note Cobra Integrated

Looking for some recommendation to replace stock tubes in AN Cobra. I am getting a used Cobra soon and being a tube roller quite often just need a little direction for other tubes you guys are using in Cobra. I assume 4 power tubes would be the fist in line to replace to get different sound. Will other 4 small tubes have also significant effect on sound when replaced? I realize that AN tuned this Cobra to sound best with the stock tubes but every system is different and tube rolling can achieve much better results. Your advice is very appreciated.


Input tubes have the most effect on sonic signature, specifically the gain stage tube.

I don't own a Cobra but have an AN preamp and DAC. Have also owned a few tube amps.

The Cobra has some unusual preamp tubes. I’d leave the 6AU6 alone for the moment. You could try rolling the GE 5670 with Western Electric 396A.
When power tube time comes, try new Tung Sol EL34B or 7581A.

First, Gold Lion KT77 to replace EL34. It improves the sound with more analytical way.

Then, replace GE5670 with WE396a / NE396a. It will becomes more musical. But you may found it is still not full enough. 

Finally, replace GE 6au6 with Mullard 6au6.

You won’t regret to own Cobra after all these………