I have an amplifier here atm from Rhapsodio which was included in the RDB+ tour I'm involved in.. they call it P&D Amp-k Pro..
It cost $250
Specs can be found here: http://rhapsodio-cmw.com/?p=1281
Today I had a chance to test the amp briefly beside C&C BH.
As you can see it's somewhat large, probably more suited for desk top enviroments, runs on x2 - 9v battery's which is claimed to get you 20 hours run time. It's very simplified next to something like C&C BH's features offering only a power switch, input / output and volume pot, I guess what matters is how it sounds. Because the amp doesn't have any switches or bass boost C&C BH has been disabled in low gain mode with both LF and SF switches off. Output1 was used and Rhapsodio's RDB+ Hybrid.
Sound
The Amp-K Pro leans a touch more towards warmth than BH with slightly forward mid range, the low end is meatier, more prominent and can become a touch excessive on some songs for my preferences, but the mids do a good job of pulling through on top., I guess with no bass boost switch Amp-k has been tuned to please the majority of people who enjoy a full low end. The forward mids tends to jump out at you more so than BH with also better detailing levels and slightly more aggressive micro detail.
Where I am having problems making the most of Amp-k Pro is it doesn't sound as refined, I can certainly sense the music, but not much of a black space behind that, there's no backdrop I've been able to pick up yet. In terms of clarity they're about even, if I had to say one has more it would be Amp-k Pro, C&C BH would really need it's LF switch on to take any full prizes there. But the main thing here I sensed was the Amp-k didn't sound as smooth there was some grain I could pick up in the mid range. I will also note there is channel imbalance which prevented me using the amp with IEM's at very lower volumes, that maybe a problem for some people.
I've only listened to the amp briefly, not one amp wins here, this is just a mini sample of my discovery. I guess when BH gets 80 a charge, much smaller, doesn't need x2 - 9v batteries seems the logical solution however, I haven't been able to try any full size headphones with Amp-k, which it seems geared towards. I would need to spend more time with it alone without switching between both to understand what's it's trying to say..
It often takes more than a few days to grasp what a piece of audio gear is trying to tell you,, for that reason I'm keeping this very short. I'll be honest, I dislike devices that require battery's, especially ones that need to be replaced or charged every 20 hours. I understand 9v's are the best way to get good power to an amp but far from my favourite alternative enjoying this audio hobby, but the Amp-k Pro regardless does show good signs of potential.