Originally Posted by Saint_1
Well the new Zana Deux is an OTL design, and by all accounts a fantastic headphone amp. It's actually a single ended triode OTL (SE/OTL) so, I'm not sure if it can drive the demanding K1000s. Although it does also use those giant 6c33 power tubes -- which gotta have some juice...
Hope that helps!
Unfortunately, the Zana doesn't do very well with the K-1000. It'll play, but neither the Zana nor the K-1000 give off the glorious sound each is capable of. The 6C33C tubes are run very conservatively and they don't put out as much power as the K-1000 needs.
Since the K-1000 is designed to be run from an 8W or greater speaker amp, look for an OTL for speakers, not headphones. I don't know if you'd be willing to DIY, but there are some terrific OTLs at Transcendent Sound
. The T16 puts out 15W, which would be about perfect for the K-1000. However, any of Rozenblit's designs would do well - he is one of my favorite designers.
You might also want to look into an Atma-Sphere S-30 (new or used) for the K-1000. Atma also makes great OTLs and Karsten's designs are quite good, too.
Of course, you could use your Graaf monoblocks to drive the K-1000, as well.
Also, you can change the K-1000 pigtail to provide for balanced operation. I strongly recommend against rewiring a K-1000. For one, it is a tricky job, one that can melt a voicecoil if you make a small mistake. AKG no longer provides service for the K-1000 and it is my understanding that AKG is out of replacement drivers. It is not worth the risk.