May I suggest checking out the Digital Amp Company's Cherry line?
Circle here and made in Allentown PA.
In StereoTime's excellent multi-reviewer review, one fellow compared a Cherry Plus to NuForce V3s, using a P-9 preamp:
My brief experience with the Cherry Plus was a revelation in the possibilities of so-called “digital amplifier” technology. Up against my reference of Nuforce’s Ref 9 V3 SE I was thoroughly impressed at how well the Cherry Plus performed especially considering their similarity in price. One of the immediately noticeable differences is the higher output gain level the Cherry Plus had relative to the Nuforce V3 SE. Whereas I spent a good deal of time listening with the Nuforce P-9 set around the 12 to 2 o’clock volume knob range with the Nuforce amps, I generally kept the P-9 around the 9 to 11 o’clock knob range when paired with the Cherry Plus. The majority of my at home listening was of WMA Lossless ripped files off of my Windows Home Server via a Squeezebox Touch through a Perpetual Technologies P-3A DAC.
One of the Cherry Plus’ greatest strengths is its speed, clarity and authoritative weight. For example in listening to George Duke’s “Every Day Hero” from Dukey Treats (Heads Up, CD) the Cherry Plus offered up a torrent of gut bustin’ grip and sublimely delineated texture to this funky track that excelled past my Ref 9 V3 SE’s performance in terms of clarity, weight and soundstage depth. The Cherry Plus seemed to have more headroom for grander dynamic sweeps.
I have only once heard my Cherry Plus at the same time as a Spectron, in a venue/system I was not familiar with and I don't know the version of the Spectron. The Spectron was certainly much slower and duller sounding than the Cherry.
Good luck with your search
-Mike
