Given all the caveats needed to qualify an opinion (stereo system, setup, and room acoustics), here’s my take on the combination of PrimaLuna Prologue Premium preamp and NAD M22 power amp. I had been using a Musical Fidelity A3.5 integrated amp (solid state) for years but wanted to hear what a tubed preamp and SS power amp combination sounded like. I wasn’t able to listen to the Prologue Premium matched with the M22 before purchasing but did audition the M22 with a couple of other tubed preamps, as well as the NAD M12 digital preamp. I really liked what I was hearing; the M22 seemed to impart very little of its own sound and had plenty of reserve power to drive 4 Ohm speaker loads. (Important because my Dynaudio Contour S1.4 speakers are rated at 4 Ohms nominal impedance at 86 dB efficiency.)
Despite not being able to audition the Prologue Premium with the NAD M22, the PrimaLuna preamps were receiving plenty of accolades so I decided to try the combination at home. The store owner said if I didn’t like the Prologue/M22 match-up he’d be willing to work out a trade. When I hooked everything up at home I was pleasantly surprised at how much better my stereo sounded (clarity, drive, tonal richness), but also somewhat disappointed at the bass response; it seemed overly emphasized. Plenty of punch to drum kicks and a rich fullness to bass guitar plucks but the bass frequencies sometimes dominated the overall sound.
Rather than assuming that the Prologue Premium was highlighting bass notes, I worked on fine-tuning main speaker and subwoofer output and room response. What had been optimal speaker positions and subwoofer output levels using the A3.5 integrated amp weren’t working with the Prologue/M22 combination. So after adjusting the cutoff frequency and output level of the subs and positioning the main speakers to have less room reinforcement, the tonal balance was much better. Still, the Prologue Premium preamp paired with the NAD M22 does draw my attention to the lowest octave of music. Not in a distracting way, it’s that now I have more of an appreciation for bass lines and drum rhythms.
I have to qualify my perspective by saying that I’ve lost some of my upper frequency hearing range so I can’t speak on how the Prologue Premium/M22 combination handles the high notes. I can say that the pairing provides a sound that is pleasantly rich (without being lush), satisfyingly articulate (certainly not clinical), dynamically punchy (catches your attention), and portrays voices and stringed instruments with a naturalness that was missing from some recordings. Euphonic? Yes, but I like the sound of it. :-)
Regards,
Tom
PS: The Prologue Premium has a relatively high output impedance (2800 Ohms unbalanced) and paired with the relatively low input impedance of the M22 (17,000 Ohms unbalanced), many would say this is a potential mismatch but I haven’t noticed any of the potential problems often warned about.