Pre/Power Amplifiers

Beyond its slimmed dimensions and encouragingly toothsome power specification, another reason the MI502 might entice non-CI buyers is the efficiency promised by its Class D technology. As measured by PM, the MI502's idling power consumption is 40W, efficiency better than 85% and standby draws just 1W. Moreover, the MI502 will automatically switch into standby if no audio signal is detected for 30 minutes.

Whipped Cream
The simplicity of a power amplifier means you can set one up and be ready to listen in mere seconds. And in the case of the MI502, there's just a six-second gap between hitting the standby/power button and the amplifier sparking into life. This sense of speed of delivery is continued by the performance. The amp has the lightning reflexes I've experienced with some other Hypex-based designs, but McIntosh seems to have found another gear, delivering whip-smart responses to the cut and thrust of music. In particular, it sounds superb with up-tempo works – precise, punchy and effortless. There's also a wonderful feeling of power, even if the MI502 doesn't quite manage to channel its grunt into huge, bass swells. It's still cheeringly good with the low-end stuff, particularly musical basslines, and it meets dynamic bursts head on.

I'm loath to say this rackable amp sounds bigger than its physical size suggests because the sheer efficiency of Class D amplification is certainly nothing new, but it clearly has the drive needed to partner floorstanders hungry for power. Through both the Kroma Atelier Stella Xtremes [HFN Feb '23] and B&W 703 S3s, 'New Walkin' Blues', by Paul Butterfield's Better Days [Rhino Records; 44.1kHz/16-bit download], enjoyed a big, fat portrayal of its stomping bassline, keyboards, and guitar. Similarly, the 1975 live recording of 'Turn The Page' by Bob Seger & The Silver Bullet Band [Live Bullet; Capitol Records 5099909833029] was nothing if not an atmospheric listen as the MI502 placed musicians upon a soundstage with front-to-back scale.

I partnered the amp with sources including a Primare PRE35 [HFN Dec '19] for a balanced connection and Oppo UDP-205 CD/SACD player [HFN Jul '17]. Via both the result was a largely neutral sound, especially in the bass and lower-mid, and with the transparency to reveal the limitations of the source when given a CD rip of the title track of Prince's Purple Rain [Warner Bros/NPG 9362-49132-0]. Pairing the McIntosh amp and Oppo disc-spinner created an easy-to-use two-box set-up that yielded a fine performance with Barb Jungr's cover of Bob Dylan's 'Sara' on SACD [Linn Super Audio Collection: Volume 5; Linn Records AKP 389], where the delicate handling of her haunting vocal was countered by the weight and body of the piano that accompanied her.

Speed King
Back to the amp's quick wits. A recent C4 television interview with Rick Rubin [HFN Jul '16] revealed the producer's thoughts on recording the speed metal band Slayer, for their 1986 album Reign In Blood; the bearded genius decreed the fast, precise nature of drummer Dave Lombardo's playing meant he had to rethink how he worked. Listening to 'Ghosts Of War' through the MI502, from the also Rubin-produced South Of Heaven [American Recordings 0602537352265], it became clear what he meant. The drum track is typical of the legendary sticksman – frequent double bass kicks, rippling crash cymbals, and super-fast snare and tom-tom rolls that straddle one bar to the next. It's pivotal to the sound of the band, and this amplifier captured it without smear or blur.

Boston's 'Smokin'' [Boston; Epic 88697184002] also benefitted from the MI502's speed and definition, the amplifier honing in on Fran Sheehan's bluesy bassline and giving each note a distinct presence. Meanwhile, Tom Scholz's fabled guitar tone was there to savour, and the MI502's presentation overall suited this joyous slab of rock 'n' roll, with a grit to the vocals and distorted guitars – no one could ever describe it as 'clinical'.

I spent a lot of time with the MI502 indulging classic rock and heavy metal (including the entirety of the Boston album in one foot-tapping session) because it sounded so lively and commanding with these genres. But it didn't drop the ball elsewhere; with more down-tempo tracks, spiky rhythms were replaced by a more all-encompassing heft and control. For example, on the moody, mid-paced electronica of Daniel Avery's 'Naive Response' from his 2013 album Drone Logic [Because Music; 44.1kHz/16-bit FLAC], the MI502 built a voluminous wall of synths and vocals on top of a foundation of throbbing bass.

Likewise, Bernard Hermann's eerie prelude to Alfred Hitchcock's Vertigo [Varese Sarabande Records VSD-5759], a piece with more overt dynamics despite the absence of any percussion, revealed forthright leading edges on brass instruments and a lovely smooth lilt to the background strings. Here the MI502 showed both the assured control of Hypex's modules, and a musical nature you might not expect from a 'custom install' amp.

Hi-Fi News Verdict
McIntosh's stereo amplifier might have been built to do rack-room work, but there's no reason it can't take pride of place – and look smart and sleek – in a hi-fi system. Yes, it's a Class D design, which makes it an outlier for the brand, but the on-tap power should suit any loudspeaker while its clean, neutral performance makes it ripe for 'tuning' with a preamp or source. The MI502 sounds fulsome, fast and fun.