Pre/Power Amplifiers

Surprises, at my age, could prove fatal, so I neither invite nor encourage them. Even pleasant ones. Neither do I relish my preconceptions being challenged: 'Old dogs, new tricks...' That said, and despite spending countless hours listening to assorted Constellation systems over the years, I must admit to being unexpectedly bowled over by these Inspiration Mono 1.0 power amplifiers.

At £12,998 apiece, they aren't even top-of-the-line: they are – I kid you not – the entry-level models. Stop screaming, or feigning a heart attack: this is 2019, you're reading a high-end hi-fi magazine – get over it. As much as it pains me to say it, they even seem like good value: beautifully finished (if prosaically styled), coloured in a mild silver-grey matt finish that can be cleaned with a soft cloth, well-equipped for input options, with a clever power-up routine, compact dimensions of 432x216x483mm (whd) and just about 'humpable' by one person at 24.9kg each.

Ready To Rock
Or they would be, if Constellation had incorporated a simple way of picking them up, because there are no flip-down handles or recesses on the sides. And, as the clearance between amp and floor is so shallow, it's also difficult to get one's hands underneath the units 'at each corner' as advised. Aah, why make a big deal about this? It's the retailer's concern, not yours, so let them do the schlepping.

There are a number of options for connecting each amplifier, including one balanced XLR labelled 'Direct' mode for use primarily with Constellation preamps. For other makes, you have another XLR to choose alongside a single-ended RCA. A toggle selects between these standard balanced and single-ended inputs. Also via the back panel are a remote power-on 12V trigger, a USB input for firmware upgrades and servicing, plus two sets of stout, multi-way binding posts to allow bi-wiring.

With an Audio Research REF 6 preamp [HFN May '16] driving the Inspirations and Wilson Sasha DAW loudspeakers [HFN Mar '19] connected with Transparent cables, the system was up-and-running in minutes. The switch-on/off procedure is slightly unusual – after turning on the master power toggle on the back of the amps, illuminating the LED on the front, glowing red, you then push in the left side of the bar on the fascia for three seconds, and the LED flashes green. This initiates a warm-up period, after which the LED turns blue and you're ready to rock.

Muting simply requires a press and release on the left side of the bar at the front, while another press unmutes it. Turn-off requires holding the left side of the bar for three seconds. The LED then blinks red, indicating that the amp is in cool-down mode. After one minute, the LED will glow solid red, putting it into stand-by mode.

In The Mode
As was swiftly determined, I agree with Constellation's advice in the manual that 'to get the best performance from the Inspiration amplifiers, you must use an XLR input'. That means either of the XLR choices, even if selecting between the standard or lower gain 'Direct' modes was less straightforward. However, while I did not have to hand a Constellation preamp, HFN's editor confirmed that the high (maximum 55V) output of the REF 6 was ideal for driving the Mono 1.0s in their 'Direct' setting.

My notes concur with PM's findings, as one swaps gain for subtle, but clearly desirable benefits. Power was never an issue, I hasten to add, regardless of mode, but easily detectable was a lowering of the noise floor, while the bass seemed more taut than in standard balanced mode. I must also emphasise that there may be even more to achieve when using an all-Constellation set-up, as we did with the Virgo/Centaur review [HFN Jul '13], but I also advise that the changes can be affected by the choice of speakers.

Starry-Eyed
Commencing with a sonic blockbuster, just because I was in a hell-raising mood that day, I fed the system the raucous, woofer-worrying Hail, Sousa! [Vanguard Stereolab VTC i650, 7½ips open-reel tape]. This was proclaimed at the time – 1968 – as 'The Largest Band On Records – 100-Men Strong!' and it delivers (to my ears) more unbridled musical power than any recording I have ever heard.