Outboard DACs

The same goes for the three output modes. It'll be a matter of personal taste whether you plump for 'solid-state', 'tube' or the almost caricature 'tube+' mode, which is clearly designed to sound like the apocryphal valve amp. Premium audio components include an all-analogue ALPS rotary volume potentiometer, Elna Silmic capacitors and Dynacaps 'super capacitors'. And as already mentioned, the Pro iDSD Signature is built to the usual high iFi Audio standards, so while it may not be what you'd call a looker, the styling is undoubtedly purposeful.

Power A'plenty
However, whether you use the new Signature model with or without all the pre-listening fiddling, you're likely to find much to relish here: yes, the designers may have moderated the output power a little, but the quoted headline figure – for the balanced output – is still an impressive-looking 4000mW/16ohm. Unsurprisingly, the Pro iDSD Signature still sounds effortlessly powerful with a range of headphones, including my usual suspects from Austrian Audio, Bowers & Wilkins and Focal, while balanced listening was assessed with a pair of the still-excellent original Oppo headphones, the PM-1 [HFN Jul '14].

Even with highly commercial music, presumably not mixed for ultimate audiophile appeal, the Pro iDSD Signature drives headphones with a combination of warmth and tight control that's impossible not to enjoy, while delivering fine insight into the innermost depths of a mix. And any amplifier able to have the listener enjoying multiple passes of the title track from the 30th anniversary set of Roxette's Joyride album [Parlophone/Roxette Recordings 5054197107153] is clearly doing something very right…

The Late Shift
What's more, when it came to the many curios contained on David Bowie's Brilliant Adventure (1992-2001) bumper 11-disc box-set [Parlophone 0190295253479], the iFi Audio/Oppo combination had me listening long into the night. I was transfixed by the sheer strangeness of his revisiting of material from the 'Laughing Gnome' era on the legendary Toy album. Highlights included the anthemic 'London Boys', to the glorious two-disc 2000 'Live At The BBC' session which really lit up the early hours with the likes of 'All The Young Dudes' and 'Starman'.

Again, that combination of wide-open insight and sheer musical clout proved addictive, although I'll admit to reverting to closed-back headphones at one point, so loud was I playing the music when it came to the smouldering then thundering finale, 'Let's Dance'! And yes, I did give it another go with the Signature in preamp mode, and got just the same big-boned but highly-detailed sound.

The warmth and generosity of the sound here is a major attraction, even in 'solid-state' guise, and while it gets a bit too lush in 'Tube+', it has the ability of making any headphones you choose sound big and impressive, but at the same time tight and clean in the low end, underpinning all the brilliance further up the frequency range.

Playing the glorious LSO/Marin Alsop live recording of Bernstein's Candide [LSO Live LSO0834; DSD128], the combination of iFi Audio's Signature DAC/amp and B&W's P9 Signature headphones [HFN Mar '17] proved a delight from start to finish – and boy, does this performance start with a bang, with the great sweep of the orchestra in the 'Overture'. Best of all, though, was the way the resolution here made every clever nuance of the dialogue and lyrics hilariously apparent, and shivered the spine with Jane Archibald's wonderful soprano voice on 'Glitter And Be Gay'.

Wrap Around Sound
What's more, pull up a rug and sit on the studio floor with a recording such as the Gidon Nunes Vaz Quartet's Ebb Tide album – or at least that's how it sounds in this ultra-simple Sound Liaison recording [SL1050A; DXD] – and the sheer amount of detail this DAC/amp can deliver is matched only by the way it wraps the intimacy of the acoustic around the listener. In this case at least, it seems as if the performers are simply, but almost holographically, placed before you, the drums pattering and the bass and piano just set back behind the trumpet of Nunes. Simple, memorable pleasures…

Hi-Fi News Verdict
This Signature version of iFi Audio's flagship DAC/headphone amp may look a bit much for some tastes – I think I prefer the more understated styling of the 'standard' model – but there's no denying the appeal of its rich, weighty, controlled and highly informative sound. Just don't get caught up in all those filters and adjustments because this is a headphone amplifier that's made for sitting back and enjoying.