I do not have much experience with the latest generation of power amplifiers: the last comparative tests date back to thirty years ago when I gave up tubes for solid state.
At that time I had Audiostatic speakers driven by Audio Research, later by Krell, in the end I bought a Cello Palette Preamplifier and a Duet 350, since then (1996) my last power amplifier.
About two years ago I had my Duet 350 completely rebuilt, which cost many months, effort (it weighs 100 lbs) and money but it was worth it and gave me great satisfaction.
During this time my system was turned off because I didn’t have a second amplifier, so I came up with the idea of buying one.
For some time I was also interested in trying some more modern amps. A few months ago a dealer gave me the Mola Mola Kaluga on trial for a weekend and I never returned them.
First of all: Duet 350 and Kaluga have about the same output power: 350 Watts on 8 Ohms the Cello, 400 watts on 8 Ohms (approx. 380 watts measured) the Mola Mola.
Once a month I compare them at matched volume because the Cello has a slightly higher output. Both are top notch amplifiers, Kalugas are extremely neutral, Duet 350 slightly coloured, the preference for one or the other could depend on tastes and personal priorities.
From an objective point of view the best qualities of Mola Mola are effortless and ease of drive, neutrality, a powerful low bass, detail, silence (the dynamics and resolution in the -ppp- is breathtaking)
The strengths of Cello are musicality, roundness, density, with some programs the emotional involvement is greater because the medium-low range, approx. 120-300 Hz is somewhat emphasized and the first octave is a little rolled off.
Mola Mola is just the opposite.
Sometimes, in some well known recordings, I can hear subsonic sounds like subway noises which I was not aware of.
Fresh out of the box, at first glance Mola Mola may seem less powerful in the bass but the opposite is true.
I guess that those of you who listen mainly to Jazz, blues, pop, rock etc. may prefer Cello.
Five months after my purchase, I find that I am using almost only Mola Mola.
From a practical point of view, Mola Mola wins hands down. They are very small, lovely, handy amplifiers, they do not heat, they hide well behind the speakers, you can use very short cables and they consume little electricity.
Twenty years ago for us SL users there was little alternative to big and heavy amplifiers. I am convinced that the old technology (be it called class A- AB, transistors, mosfet, tubes and so on) will be wiped out in five years from now.
(Krell MD-2, Aurender X100L, Weiss INT 204, dCS Scarlatti DAC, Mola Mola Kaluga, Sound Lab A1)