Link Spotlights

Link Spotlights
The Pinnacle of The Electrostatic Sound

Friday, June 3, 2016

EAN First Listen/Review!
Prism Sound Callia
Stereo Audiophile 32-Bit DAC


 Pro Pedigree Transfers to Prism Audiophile DAC

by John Gatski
  I have been reviewing Prism Sound professional audio products since the early 1990s. The UK-based audio manufacturer has produced highly regarded, high-end analog and digital products over the years — from its  premium analog Maselec mastering EQ to the various multichannel A/D-D/A converters. Your studio had to have some coin to afford Prism, but the engineers always say it was worth the investment
  In recent years, products such as the Firewire-based Orpheus recording interface, as well as a series of USB-connected recording products, have put Prism squarely in the forefront of serious home recording quality, maintaining a sonic edge. And all the while , Prism continued  to manufacture in Merry Ole England..
  Knowing this history, I was quite pleased when Prism President Graham Boswell showed me his company’s first audiophile DAC — at the 2016 CES in Las Vegas. The working prototype, called Callia, sounded quite detailed and resolute, and it was predicted to come in well under $3,000.
  Based on a few days of testing and use, this First Listen preview gives an overview of the Callia, as well as a bit of hands-on time. I will author a more in-depth review at a later time, but readers will note that I am impressed by this DAC.

Features
  The $2,595 Callia is loosely based on the Lyra USB recording interface I reviewed a couple of years ago — but without the A/D and the recording studio connectivity/virtual mixer of its pro brethren.  The Callia features up to 32-bit integer, 384 sample rate PCM, and 1X-2X DSD via DoP. Bucking the ESS Sabre and AKM DAC chip bandwagon, Prism’s has implemented its favorite D/A chip, the Cirrus Logic CS4398, Prism adds a custom-designed, premium-part, analog stage for line out and HP; the DAC boasts a noise spec greater than -115 dB (20 Hz-20 kHz), according to Prism Sound’s specs.

  Throw in 32-bit/384 sample rate capability, DSD playback, a great headphone amp and its under $3,000 price, and it becomes clear that the Callia meets the criteria for an Everything Audio Network Stellar Sound Award. That is Stellar with a capital S!

  The sharp-looking Callia comes in a dark-gray, anodized front panel, and is proportioned in a 3/4 width, one-rack space high chassis. The elegant-looking DAC is quite uncluttered on the front panel, with a large line-output volume control, a separate, smaller headphone volume control, the headphone jack and the standby/input selector switch.
  A series of LEDs lights fleshes out the front panel including input indicators: (Auto, TOSLink SPDIF, RCA SPDIF, USB). The second bank of separate LEDs reveal the audio input status — a DSD LED and a PCM LED (via the word length 24-bit light LED). The DSD sample rate is indicated by either the non-illumination of the 2X light (2.8MHz) or the LED’s illumination, which indicates the 2X 2.8 MHz DSD sample rate — 5.6 MHz.

Bit/sample rate indicators
  When playing PCM, the sample rate is indicated by illuminating either the 44.1 kHz or 48 kHz LED, plus either the 2X or 4X LED. Thus, 24/96 will be indicated by illumination of the 48K LED and the 2X LED, plus the 24-bit LED. With 24/192 material, the display shows  the 48K LED, plus the 4X LED (48 x 4 equals 192) and the 24-bit LED. A 384 sample rate (a very rare recording indeed) is indicated via illumination of the 48K LED, the 4X LED, plus the 2X LED (48 x 4 equals 192, and192 x 2 equals 384).

Just enough I/O to make it a complete DAC/preamp

  Real 32-bit integer audio (not 32-bit floating point) is indicated by the 24-bit LED glowing red instead of blue. When a 16-bit recording is played, the 24-bit light does not glow at all.
  You have to do a bit of multiplication in your head to know exactly what sample rate you are playing beyond 44.1 and 48, but I am glad Prism included this info, especially the PCM word length indicator, I have been pushing DAC manufacturers for the past eight years to include that feature, and now many of the major DACs have it.

The back panel
  On the back panel, the Callia sports a set of balanced XLR line outputs, a pair of unbalanced RCA line outputs and fthree digital inputs (SPDIF TOSlink, SPDIF RCA, and USB 2.0). The 32-bit PCM audio path and and sample rates higher than 192 are only active via the USB input. Thus, computer players, such as Audirvana, JRiver, VOX, etc, are needed to play the ultra-res music.
  Callia’s rear panel also features a series of small DIP switches that allow tailoring the gain of the headphone amp for those HPs that need a bit more grunt to make ‘em loud enough. I left it in the stock position, which was plenty of gain for the AKG K812 and the Oppo planar magnetic PM-1 headphones I used for the listening sessions.

Listening impressions
  My early-bird sample Callia came with no remote control (they don’t come with one apparently), but it was easy to set up. It was plug and play with my Apple Macbook Pro using the included USB cable, as well as external sources via the SPDIF connections. I connected the Callia to the Apple laptop and commenced playing. I connected the DAC;s XLR line outputs to a Pass Labs X350.8 amplifier, which drove my MartinLogan Montis loudspeaker. I also listened to various bits of hi-res music via headphones. Having heard the prototype at CES and having reviewed the Prism recording interfaces that utilize the same DAC chip, I was sure that I would like the sound of the Callia in my various set ups. My assumption was quite correct.
  When playing a PCM 24/192 copy of the Tom Jung-recorded Warren Bernhardt — So Real SACD album, I was very impressed with Callia’s accuracy. Through my AKG K812 headphones, the "Autumn Leaves" track was transmitted from the DAC HP output with  a smooth, precise, transient character with a detailed, percussive soundstage The Steinway piano was spot on —without any audio grit when listening to the high-amplitude, upper-register piano notes. Prism’s Boswell said the analog signal path design must match the crucial stages of the D/A circuit — in order to get the best sound from a DAC. I have to agree; the Prism DAC is the best-sounding, Cirrus D/A chip-equipped audio DAC that I have ever auditioned!

Everything sounds brilliant
  My positive impression never wavered — no matter what kind of music I threw at it. A test DSD piano recording from seven years ago,  done by Tom Jung who used the incredible Joe Grado HM-P1 omni microphones, — showcased the Prism DAC’s ability to squeeze out every bit of nuance from the piano/room sound.
  Prism’s Boswell said the analog signal path design must match the crucial stages of the D/A circuit — in order to get the best sound from a DAC. I have to agree; the Prism DAC is the best-sounding, Cirrus D/A chip-equipped audio DAC that I have ever auditioned!

  The DSD version of James TaylorJT album showed that the DAC is not just for Classical and Jazz lovers. Pop and Rock sounded good as well. The deep layer of instrumentation on JT’s “Handyman” (strings, Fender Rhodes piano, double-tracked backing vocals and crisp percussion) are delivered as good as DAC’s two to three times the price.
  I also played 2L 24/352 (DXD) Classical recordings and my own high-sample rate recordings, made at 24/384, to test the Callia’s ultra hi-res playback capability. Using Audirvana from the Mac, the Callia had no problem decoding the files. I even played a 32-bit integer file (a 24-bit audio file up converted to 32 bit by padding it with extra 0’s) to see if the DAC could detect the 32-bit audio file from the Mac laptop. It did, indicating 32-bit by turning the 24-bit light from blue to red — just like it should. This was done via USB from the Mac, again using Audirvana as the player.

More to come
  This first listen/look at the Prism Sound Callia is just a sampling of the in-depth review process that it will undergo over the next few weeks, including some in-depth measurements from our bench tester Bascom King. But just from these initial listening sessions, the Callia is as good as I expected. And the HP amp is better than I expected — since I had not listened to the circuit via my own phones at CES. The HP amp ranks up there with other top-notch DACs, such as the Benchmark, Mytek and Oppo HA-1.
  From my brief, few days of listening, my initial impressions are that the Callia is a classy, open, detailed-sounding DAC with plenty of width and depth in the stereo presentation. Throw in 32-bit/384 sample rate capability, DSD playback, a great headphone amp and its under $3,000 price, and it becomes clear that the Callia meets the criteria for an Everything Audio Network Stellar Sound Award. That is Stellar with a capital S! Click Callia for more info.



  John Gatski is publisher/editor of Everything Audio Network. Articles on this site are the copyright of the ©Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited. ©Everything Audio Network

No comments: