Outboard DACs

The Diamond DAC just works, converting digital to analogue using technology based on AKM's top-end AK4490 'Velvet Sound' converter chipset. SPL also includes its DLP120 (dual low-pass) filter network after the conversion system, with one roll-off frequency and rate for LPCM and another for DSD, the latter otherwise including higher levels of ultrasonic noise. All this is implemented using the company's 'high voltage' VOLTAiR op-amp modules, a proprietary technology used throughout SPL's Professional Fidelity series.

Diamond Sparkle
I made full use of the input and output flexibility of the Diamond DAC, feeding it from my network player using one of its coax inputs, from a computer running Roon via USB, and also using the USB input to connect it to a network transport. I also ran the fixed output into an integrated amp and variable out into a Naim NAP 250 DR power amp [HFN Dec '15]. And the first takeaway is that, whatever input, file format or output used, this DAC is entirely consistent in its operation and sound. Yes, one might wish for a remote control just to adjust the volume – as SPL offers on some other models – but beyond that the Diamond lives up to its name with a sparkling performance, allied to a simplicity of operation enabled by its minimalist design.

The beauty of this DAC is the directness of musical communication it brings, sounding super-clean and precise without ever appearing sterile or anonymous. Instead, it combines a really deep dive into both recording and performances with all the heart and soul required to ensure the listener engages with what's being played. With The Cardigans' First Band On The Moon [Stockholm Records 533 117-2], that means a delicious view of Nina Persson's vocals, and a real appreciation of the skill in both the arrangements and the musicianship, with even the over-familiar 'Lovefool' sounding fresh and engaging.

Calling Elvis
Furthermore, SPL's DAC actually seems to relish getting its digital teeth into the most diverse of recordings, ensuring the likes of the lavish four-disc 'Super Version' of The Songs Of Bacharach & Costello [UMe; 96kHz/24-bit download] are a real delight. This comprehensive survey is impeccably recorded, and the music reliably wonderful, from Costello's plaintive rendition of 'God Give Me Strength', with its muted trumpet and lush strings backing a superb close-up vocal, all the way through to the near-demo feel of Bacharach singing 'Lie Back And Think Of England'. The latter is a consistently smile-raising little throwaway, but still with a beautifully weighted piano. Costello's live version of 'I Just Don't Know What To Do With Myself' sounds suitably '1970s', but is still impassioned, while Cassandra Wilson's take on 'Painted From Memory' benefits hugely from the SPL Diamond's weighty but crystal-clear presentation.

Not that you need to rely on hushed vocals and fluid strings to hear this DAC at its best, for it's 'at its best' with just about everything you choose to play, including the fuzzed-out guitars of the title track from Lenny Kravitz's Are You Gonna Go My Way [Virgin 0777 7 86984 2 5], underpinned by a slamming rhythm section. Then again, the stunning old-fashioned band backing Willie Nelson on his recent I Don't Know A Thing About Love tribute to the songs of Harlan Howard [Sony/Legacy Recordings 19658800362] is delivered with wonderful warmth and ambience.

Breathing Space
The old boy's voice still sounds great now he's back in his country groove after some recent opinion-dividing excursions into the 'Great American Songbook' territory. Not bad for a singer just weeks before his 90th birthday when the album was released, and the Diamond conveys all the character of the vocal.

What's more, SPL's Diamond DAC is excellent when it comes to soundstaging and ambience; it brings out the slightly distant sound of Adrian Butterfield and Silas Wolsston's new recording of Bach sonatas for violin and harpsichord [Somm CD0664-2], affording the music space to breathe in the church acoustic while still giving an entirely natural-sounding tonality to both instruments. Nor will this DAC place limitations on the music you play through it, as it doesn't sound noticeably 'better' with one genre over another. It's just at home pounding out the beat and lush arrangement of Orbital's 'Ringa Ringa' [Optical Delusion; Orbital Recordings 96kHz/24-bit download], as it is with the Bach sonatas. Here the deep bass both hits hard and low, and drives fast, while the ethereal rendition of the old nursery rhyme sounds suitably unearthly, before the album slams into the unstoppable beat of 'Day One', again with soaring female voices.

Rich Rhythms
True to its studio heritage, SPL's Diamond opens a window on any recording, be that thumping electronica or the richness of the LSO/Gianandrea Noseda 'DSD EP' of Prokofiev's Symphony No 1 [LSO Live LSO0363D; DSD256], in which the scale of the orchestra is as impressive as the way the DAC reveals the rhythms and tonal shades of the performance.

Ultimately, provided the rest of your set-up can reveal all the fine things it does – its clean sound and transparency – this DAC should never disappoint, whatever kind of music you choose to throw at it.

Hi-Fi News Verdict
It might be the most basic digital device in SPL's 'Professional Fidelity' range of consumer products, but the Diamond DAC is both superb-sounding and something of a high-end bargain. By focusing on essential flexibility only – no fiddly filters! – the company has come up with a design that's both easy to use and capable of excellent performance across a wide sweep of musical genres.