The latest edition to Prism Sound’s USB range is the Callia stereo DAC – designed to provide Prism Sound quality for playback and monitoring wherever a USB or S/P-DIF/TOSLINK connection can be found.  With the release of the Callia Prism Sound are spanning two markets – both professional and audiophile – anyone really interested in digital playback of the highest quality. 

Someone at Prism Sound has certainly been paying attention when it comes to packaging and presentation. Unboxing feels like a luxury procedure and the supplied software comes on a premium USB stick. On Windows systems you will need to load the supplied driver while on MacOS no driver is needed, but an optional firmware loader app is recommended if you want to update your firmware.

The Callia will be familiar to anyone who has seen a Prism Sound Lyra – gun metal gray – understated presentation in a physically refined package with tasteful blue LEDs.  The front panel controls comprise volume, headphone level, input select and an array of said LEDs indicating source, sample rate and format.

Round the back you have a USB input supporting a plethora of formats. S/P-DIF on phono and optical on TOSLINK. And analogue outputs, unbalanced on RCA phono connectors and balanced on XLRs. There is a also a set of DIP switches which set DSD maximum level and options for headphone monitoring.

Talking of DSD – the Callia supports DSD playback of DoP files up to DSD128 over USB and DSD64 in DoP format over the S/P-DIF inputs.

First I tried the Callia against some well respected hifi DACs – the source was a Cyrus streamer, amplification by Nytech and speakers varied from Dali Zensors through models from Dynaudio and Spendor.  Very quickly it became obvious that the Callia offered a very high standard of playback, leading the DAC pack.  None of the sibilant top end or ‘closed in’ issues that were present in some of the competition were to be heard on the Callia’s watch. 

Back to the ranch – I’m working on a retro power amp shoot out and I had Naim, Nytech and Quad poweramps at my disposal with speakers from Tannoy and Harbeth. My standard DAC is the tremendously excellent Marenius DAC S2 – usually driven by the equally excellent Marian Seraph AD2 sound card, over AES3. And here I have a nit to pick with the Prism Sound – no AES3 input.  However to be fair the Callia’s S/P-DIF input can handle AES3 formats if you have the right adapter and I do and it worked fine.

Two aspects of the Callia’s performance struck me as particularly note worthy. Excuse the pun.  First the independence and coherence of individual instruments – often described as micro dynamics. With lesser components kick drums tread on the vocals or bass guitars smear the strings – no sign of these problems with the Callia.

On the other hand one of the trademarks of quality performances is the musical interplay between instruments and or voices. And top quality equipment retains the subtle nuances of performance including the intention  of the musicians. I found the Callia often laid bare not just the sound of the music but also the soul of the performance. 

In an effort to squeeze the last drop out of the Callia – I tried the headphone outlet.  The Callia headphone amp has power to spare, able to drive the 250 Ohm Beyerdynamic DT1990s to levels beyond comfort. I bailed well before we got to 11. 

The resolving power of the Callia  was now fully revealed – layers previously partially obscured brought to the light – percussion benefiting particularly here and also the acoustic space around instruments – so often shrunk by lesser components – blossomed and bloomed. Tonally the Callia is the image of neutrality – the bottom end is extended and well controlled – the mid range clean and uncoloured and at the top end a complete absence of any unnatural emphasis or hardness.

In one sense summing up the Callia is not difficult – it is a superb piece of equipment that handles a wide range of formats, is beautifully built, a pleasure to operate and has a pedigree second to none.

Key Features:

• Playback sampling rates from 44.1kHz to 384kHz
• Balanced +14dBu XLR and 2V RCA phono outputs
• Optical and co-axial S/P-DIF input
• Low-Z headphone output (adjustable sensitivity)

RRP: £2,158.80 ($ 3,014)

About the reviewer:

Alistair McGhee began audio life in Hi-Fi before joining the BBC as an audio engineer. After 10 years in radio and TV, he moved to production. When BBC Choice started, he pioneered personal digital production in television.