Some time ago I've had the chance to test their $40 amp. http://www.ebay.com/itm/MUSE-Tube-6N11-Class-Headphone-Amplifier-Pre-AMP-/290520582669 It's funny looking, nothing more.

I'm using the laptop feeding a DAC/amp combo, so IME: digital player on pc at max vol, then set the (analog) volume control of dac-amp to my level need. YMMV, of course.

Hi,   Even though not really portable, the Portable/Desktop Amp from QES Labs has a lead-gel re-chargeable battery, USB DAC option, and it's pure class A . It can even drive 8Ω loads ! Worth checking. A review is here.

Heard the Muse too. At last, it's a funny looking amp.   Quote:  

A very good match would be the HPBA-2 from QES Labs. A super transparent amp, revealing with the analytic 800. A review is here.   .... and should be within your budget. Quote:  

I would prefer the HD-600 over the 650, you'll be substituting a grey and black plastic finish for the 650s' fancy titanium metallic housing, but you'll still be getting a high-end pair of open-air headphones while saving enough money to buy a really nice amp as you listen to your music of...

Even though not w/in your budget, I extensively used the Denon C710 driven by the Portable/Desktop amp from QES Labs. It was the only (trans)portable amp to sublimely drive the low-ohm IEMs. It can drive as low as 8Ω cans, and is full class A design. A detailed review here.

Quote: +1  

E5 should do the trick. Will suit your need.

Upgrading your can was definitely a good move. Try to save some $$$ for a good amp. In the $500/600 range, you might have some interesting stuff on ebay..... A portable-desktop amp, it drives 8 to 600Ω loads, has USB DAC option. The Icon HDP.   I think your D7000 deserves the best.

Quote: For around $500 I would suggest this amp. It falls in between a portable and desktop, battery operated, and has the USB DAC option, so you can connect your laptop. You save the rest for a better can.

Buying in EURO helps a lot when buying from U.S. or Asian market, as they quote in USD.

Quote: I recently tested a battery-operated (almost) portable amp. A review soon. In the meantime you can have a preview here. It has the USB DAC option, I use it anytime with my laptop. SQ is top-notch, it's a Class A S.E. design.

Sorry, I realised I posted in the wrong forum. Moderators: pls move to portable headphone forum. T.Y.

Hi folks,   Mine are the black version. The spec's are: Impedance 16Ω, SENSITIVITY: 110dB/mW MAX POWER INPUT: 250mW DRIVERS: 11.5mm CABLE: .7 meter OFC + .8 meter extension included WEIGHT: 5.6 grams excluding cable COLORS: Black or silver The Package You get a leather-like modular...