Optimizing the Crack for AKG K340 headphones

[Tom-s]

I've used the search functionality to find an answer but it didn't show.
Went with a Crack because of the customization possibilities that come with a DIY kit.
Following this i bought a pair of AKG K340 headphones because good quality for cheap + DIY upgrade potential.
Now i've read these are very power hungry and gain from every bit of extra juice you can give them.

My plan:

- First build the Crack and add the Speedball.
- If received in time, build with or add Valab 23 step potentiometer upgrade.
- Switch mod for different tubes on speedball.
- Tweak headphones (cables, earpads, cotton, plastic screen etc etc.).

What else is possible to get more out off the crack for these headphones?
What tubes would you suggest for more power demanding headphones or am i wrong in thinking a higher gain tube (ECC80?) would make them sound better?

[Paul Birkeland]

The K430 is well suited to the Crack's topology, you won't need to change anything to optimize it for use with the Crack.

 For information on tubes, I would recommend having a look at the Tube Rolling with Crack thread, which is quite lengthy and comprehensive.

The Crack will make way, way more than enough power for the 400 Ohm K430's, I wouldn't worry about that.

[Tom-s]

Thank you for the reply PB.
Been reading through the rolling thread for a few days now and found a lot off suggestions i want to try.
That's where i found that installing the switch mod on the Speedball would be worth it so i could switch between different tubes and run them at optimal voltages.
I only know these K340's are very sensitive for having enough "headroom", like the AKG K1000.
And i also read the S.E.X. would be best for the AKG340 but that was beyond my budget.
I know the Crack will be up for the task, i looked into that before i bought it.
Many members on here seem very happy with the combination.
Aren't there any (relatively easy) mods to give these headphones a little more "headroom", just to try?

[Paul Birkeland]

I think you need to listen to the stock amp first to determine how much additional headroom you actually need.