Best / Cheapest desktop micro-amp?

best?  likely a First Watt

Dayton DTA 120 Integrated 

Out of your choices, I would probably choose Zamp because of linear power supply and just brute force. Unless you wanted something to manually control volume (instead of using Windows Volume or separate preamp). Otherwise, I would personally go with Sprout because of the sonic signature.  Though, Sprout is a swiss army knife of features, which you are paying for in addition to the amp.   I know that NAD tends to go on the warm side of things where PS Audio is more neutral/fast. I don’t know of any other options. Peachtree Integrated/DAC? But that’s at least twice your budget.

Powered speakers.

@dweller I already built the speakers. :) They're not powered. I'm not looking to replace them.

@auxinput I heard the NAD master's DAC. OUCH.

@jl35 That IS an interesting option, especially at $80!

Surprisingly good sound 

The Audioengine N22 has gotten some great reviews and is class A/B (22 wpc). It was on my radar when I was looking for a "cheap & cheerful" amp. I ended up with the Dayton DTA-120 for my work space and a Fleawatt TPA3116D2 for another listening space. 

I have the Zamp paired with an audioengine D1 and it’s a very clean and detailed desktop setup...no hiss. There is no mid bass boost like most other small amps have including the Sprout. Also less risk of ground loop compared to Class D. The Emotiva mini X is also a steal. I own both. 

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I always like MFs styling! 20 watts is a little low, and it lacks a headphone jack, even though it does have a built-in DAC!

Maybe check out Temple Audio--class D units handmade from Britain.  Very low distortion and stable into low ohms.

I have their monoblocks.  Very smooth and detailed.

I'd love to hear your opinions to how their Analog Devices chip implementation compares to all the pricier offering mentioned in your class D thread.

Benchmark AHB2 has a small foot print and a killer sound

@lancelock

The AHB2 is a good idea, but it's a little large for my needs, physically, and definitely out of budget. Hopefully others will try this out though!

Best,

E

A few years back, I built a TK2050 module in a wooden cigar box... I've since forwarded it on to a friend,  but this was a very nice sounding little amplifier. If I remember correctly,  I used a regulated 20v supply... Just another thought as you wade through these. Tim