Ever since I raved about Krell’s K-300i integrated amplifier after it was released in early 2019,1 I’ve wanted to review other Krell products. After spending more than a year and a half (since its prerelease announcement) awaiting the opportunity to review Krell’s new flagship mono power amplifier, the KMA-i800 ($73,000/pair), the time has come. Both Krell models utilize the company’s proprietary iBias technology, albeit in different iterations, and both were designed by longtime Krell engineer Dave Goodman.2
In the conclusion to my K-300i review, I wrote, “The Krell … has the smoothest, most listenable, and most all-of-one-piece sonics of [any] integrated I’ve reviewed. … There’s a round edge to its images that some might equate with the gentlest sprinkling of warmth, but others would describe as listener friendly. It certainly leaves me smiling.” I thought it so excellent, and such a good buy for a Roon-ready streaming integrated with an optional onboard PCM/DSD/MQA DAC, that I urged a friend to buy one. More than three years later, he’s still smiling.
Would Krell’s new, far more powerful class-A monoblocks inspire the same excitement? As much as asking the question may sound like the first installment in a made-for-TV soap series, finding out made all the work I did carting these beasts around more than worth it.
Design and engineering
The product overview for the KMA-i800 monoblock amplifier on the Krell website lists the following key technologies: differential output; iBias—see below—paired with XD technology, which lowers output impedance; Sym-Max (Symmetry Maximization), said to virtually eliminate second-order distortion; a power supply “consisting of 5400VA of transformers and 188,000μF of filter capacitance”; power delivery via gold-plated circuit boards and silver-plated solidcopper busbars “with a very short physical path for extremely low impedance”; “Current-Mode circuitry with advanced current mirroring that is balanced, differential, and direct-coupled,” with each stage individually tuned; an output stage with “16 pairs of 200W audio power transistors and eight pairs of audio driver transistors,” resulting in a wide
