[grandcross]

Other then the Zu Mobius, that is. One that will add the impact in the bass, and possibly more soundstage.

If possible, it'd be nice if it was portable.

Oh, and less then $200 would be nice too.

 

[Borat]

Wait, are you looking for an amp or cable for your AKG's?

Because the Zu Mobius is a replacement cable, not an amp.

 

[Large4mat]

I use a HeadRoom Total Airhead with the 271's for road trips. Drives them very nicely.

As far as cables go, I've tried both the ZU Mobius and Stefan Arts Equinox. Both are very good. Both help improve the bass, but the Equinox wins hands down in the soundstage department IMHO.