Funny you should ask ... well before that I'll say I don't know a portable one but I'll be looking for one @ the Head-fi meet. What's funny that you should ask is I just setup the rig I'm gong to bring to the NYC Head-fi meet on Saturday; as far as amplification goes it consist of two E17s, one E09K, one Little Dot II+ and one Little Dot III+. I just blew the dust off my Little Dot III+ that I hadn't used since perhaps 2008. O-M-G, whoa, talk about power to spare. The amp is rated at 1000mW @ 120 ohms and 3.5W @ 8 ohms [that's right, it has speaker terminals]. So doing the math the amp it is probably delivering somewhere nearing 2 watts per channel into the 50 ohms of the MadDogs.
I happen to be using the E09K to drive it, using the Line Out, with the E17 sitting ontop decoding a Toslink S/PDIF input from my brand new [delivered just yesterday] Little Dot CDP_II transport.
It's been addictive all night and I haven't been able to unplug the MadDogs from the Little Dot III+ amp for long, sometimes going to the LD II+ but soon going back to the LD III+ [I feel like Jeremey Clarkson of TopGear fame ... wanting to yell "P-O-W-E-R" in a british accent]. But I plugged back into the E09K a little while ago to make sure I wasn't lying to you. And with the E17's treble and bass both on +4, I found what I was listening to to sound acceptable and quite articulate and clean all the way up to max volume [E17 on 0-gain]; but it did have substantially less "meat on the bone" than either my Little Dot III+ and the Little Dot II+ sitting next to it and not much of a step-up from the E17 alone. And when listening thru either of my LD amps the treble and bass are both set to 0.
Now, I don't know if David is making the Little Dot III+ anymore [tho, he never released the CDP_II either, but he did sell me a NOS device he had onhand so who knows.] I'm sure you can get many suggestions for hi powered amps in this thread. But will they be Class A amps and switchable between Triode or Pentode and capable of delivering 3.5w to speakers and around 2watts to the MadDogs for $350? Probably not. ;)
Edited by m8o - 4/18/13 at 10:58pm