June
2019

Country of Origin

USA

INT-25

Reviewer: Srajan Ebaen & Dawid Grzyb
Financial interests: click here
Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo boost, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 14.4), PureMusic 3.02, Audirvana 3, Qobuz Hifi, Tidal Hifi, Fore Audio DAISy1, COS Engineering D1, Denafrips Terminator, Soundaware D300Ref,  AURALiC Vega, Jay's Audio CDT 2 MkII & DAC-2 SE
Preamplifier: Nagra Classic, Wyred4Sound STP-SE Stage II, Vinnie Rossi LIO (AVT module)
Power & integrated amplifiers: Pass Labs XA30.8; FirstWatt SIT1 monos, SIT-3, F5, F6, F7; Goldmund/Job 225; Aura Note Premier; Wyred4Sound mINT; Nord Acoustics NC500 monos; LinnenberG Audio Liszt monos; SAG AIO, Kinki Studio EX-M1
Loudspeakers: Audio Physic Codex; Cube Audio Nenuphar; Kroma Audio Mimí; Albedo Audio Aptica; EnigmAcoustics Mythology 1; Boenicke Audio W5se; Zu Audio Druid V & VI & Submission; German Physiks HRS-120; Eversound Essence; Fram Midi 150; sound|kaos Vox 3f [on review]
Cables: Complete loom of Allnic Audio ZL3000 and Zu Event; KingRex uArt, Zu and LightHarmonic LightSpeed double-header USB cables; Tombo Trøn S/PDIF; van den Hul AES/EBU; AudioQuest Diamond glass-fibre Toslink; Black Cat Cable redlevel Lupo; Ocellia OCC Silver
Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps/sub
Equipment rack: Artesania Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc Krion and glass amp stands 
Sundry accessories: Acoustic System resonators
Room: 4 x 6m with high gabled beam ceiling opening into 4 x 8m kitchen and 5 x 8m living room, hence no wall behind the listening chairs
Review component retail: $7'250

Fish'n'chips. Unlike leaving the EU, the English would say that these two things get on very well.

So do a preamp and power amp. Together in one chassis. Snug. Served.

Where's the greasy newspaper wrapper?

Like fish'n'chips, an integrated amplifier needn't be poncey. Pass Labs never are. But what they are very much about is serious hardware with big transformers, big heat sinks, heavy chassis, heavy class A bias, high temps.

With their latest INT-25, the smallest class A stereo amp of their catalogue called XA25 hops into the same bed as a simplified front end of the existing INT-60 machine. That makes it an X-rated and perfectly pervy proposition. For Pass, it's also very compact.

So let's get onto its case and into it, first of the pater familias below, the standalone amplifier with its 2 x 700-watt push/pull power devices per channel. It's what I'd prefer by a few sonic whiskers to the heavier bigger more expensive XA-30.8 we already own.

The basic stats for its integrated version are 26dB of voltage gain, the same 25|50|100wpc into 8|4|2Ω power, DC-100kHz bandwidth at -2dB, less than 150μV of noise, a slew rate of 100V/μs and 10A of peak current which corresponds to 200 watts peak power into 2Ω. All of that fits into 17×17.9×6" WxDxH and weighs 51lbs.

As a pure single-ended design, the three inputs are exclusively on RCA. The remote switches power inputs, volume and mute. Volume by precision resistor array traverses 63 x 1dB steps.

As we did for our XP-12 review, this will become a two-writers-in-one-review job—today's theme is integration after all—between regular Warsaw correspondent Dawid Gryzb and Irish team leader yours truly.

To establish a proper place setting, refamiliarize yourself with the XA25 in our archives, also the reviews of Terry London for HomeTheaterReview, Herb Reichert for Stereophile and Steve Guttenberg for The Audiophiliac  Hifi reviewers don't always agree but in this instance, we all thought that this amp was very special. Getting it packaged with a tailor-made linestage to simplify ownership without dumbing down results should be of special appeal for many.

… stay tuned…