Outboard DACs

As is always the case, the selection of digital filters and so on is really a matter of personal taste, so I’m not going to make any ‘you must use this’ recommendations, beyond saying that I stuck to the maximum upsampling – to DSD1024 – and the BitPerfect+ filter setting. This leaves the signal unmolested save for a little analogue HF tweak courtesy of a filter previously only used in products from iFi stablemate Abbingdon Music Research. Its effect is to put a bit more air and sparkle in the treble, which can sound just a tad dull in the standard BitPerfect mode. And after some investigation of the two output stages I found the Tube+ routing to be indistinguishable from the Tube setting, which itself added just the slightest sheen of lushness when compared to the solid-state output.

Manic Mixes
Checklist done and engines started – an indicator glows green during warm-up, then turns white in solid-state mode or orange for tube – the Pro iDSD proves itself to be a very superior DAC, with massive amounts of detail smoothly integrated with a fluid midband and hefty but fleet-footed bass. Playing The Justified Ancients Of Mu Mu’s 1989 Shag Times set [KLF Communications JAMS CD3], the Pro iDSD showed how fast and hard-hitting it could be, grinding out the deep, deep basslines while revealing all of the layers and detail in the manic mixes, as was especially clear comparing the original of ‘Whitney Joins The JAMs’ with the later, more open and punchier (but Whitney-less) KLF remix on the same album.

That may be a case of throwing the rough at the smooth, though the mixes really do justify the detail a fine DAC like this can deliver, but with the silky DSD256 of the eponymous live album by the Yuko Mabuchi Trio [Yarling Records YAR80161DSD] the Pro iDSD sounds simply radiant, every tiny detail laid bare whether the DAC is used as a source, a preamp or a headphone amp. Indeed, using it with headphones including the B&W P9 Signature [HFN Mar ’17], and the Oppo PM-1 [HFN Jul ’14] in balanced configuration, the sheer amount of detail on offer, and the way it adds to the music rather than distracting from it, was quite a revelation.

Stern Test
The recording places Mabuchi centre-stage in the room, ably backed by Del Atkins on bass and Bobby Bretton on drums, and it’s hard to think of a set with as much presence as revealed by the Pro iDSD and the Oppo PM-1 headphones. But this is reality, not hi-fi hyper-reality – there’s nothing artificial going on here, but rather total communication with the music.

Switch to the valve stage if you want, for late night listening, but stick to the solid-state version for the maximum impact as Mabuchi and her boys swagger through a medley of ‘All The Things You Are’, ‘Take The “A” Train’ and ‘Satin Doll’. In a word: glorious!

Stick with DSD and the third Dire Straits album, 1980’s Making Movies [DSD64, from Vertigo UIGY-9520], and the Pro iDSD has you as soon as the band explodes out of the ‘Carousel Waltz’, that mix of impact, impetus and information revealing previously unheard detail. In fact, so grabbed was I that I immediately moved on to the band’s Love Over Gold [Vertigo UIGY-9505], also in DSD64, just to hear what iFi Audio’s finest could do with the ethereal opening of ‘Telegraph Road’ and the slam of ‘Private Investigations’. I wasn’t disappointed.

Finally to a stern test of any system – if you’ll pardon the pun – in the form of the Reference Recordings Britten’s Orchestra album [RR-120], whose performance of The Young Person’s Guide To The Orchestra by the Kansas City Orchestra under Michael Stern could have been designed as a forensic investigation of what a piece of audio equipment is doing. From the fine detail of the woodwind at the beginning of the great fugue to the way the entire band winds itself up to the crashing, triumphant climax, the Pro iDSD remained fully in control while still allowing the music off the leash. This is quite a magical little box of many tricks.

Hi-Fi News Verdict
In tune with its studio aspirations, this is one of those ‘need to know what you’re doing’ products. There’s no fast or easy way to get the most out of it, and some aspects of its set-up need work, but it rewards the effort with a scintillating sound, whether as a source or a preamp into a main system, or with headphones. Get past the complexities, and avoid adding any more, and you’ll not be disappointed.