I don’t recall seeing any of their products in person, but have seen many video reviews and feel confident stating that Benchmark products are built as solid as you can get in both build and performance. Manufacture site below:
Benchmark makes amplifiers, digital to analog converters, analog to digital converters, speakers, headphone amps, etc. For IATM the prices of the dacs are a bit high, but this AHB2 amp fits into the high point of cost for an amp here. What you get though is what matters. Plus the benchmark products are designed, assembled and tested in the US and most of the parts are of US origin.
The claim to fame with this amp is how quiet it is. “The dynamic range of the AHB2 is 132 dB, making it 10 to 30 dB quieter than some of the very best reference-quality power amplifiers”. -from manufacture site.
Here are a couple of videos about it: