Integrated Amp Reviews

Sometimes I think expensive components—I'll let you decide what constitutes expensive—should come with a big red sticker on the box that reads "WARNING! This product will probably not meet your expectations!" That's because when you spend a lot of money on something, you expect that something to have no flaws and to sound nigh perfect. Why else would you have paid so much? As you gaze at it, touch it, and listen to it, it constantly reassures you that you made the right decision by picking it over all the other, less pricey candidates. It has to be unambiguously better than any component of its nature that has passed through your system, or else, what was the point in all that upgrading?

That's a lot of expectations for a product to live up to, but then our hobby is all about expectations. How many expectations spring to mind when you think about solid state, tubes, digital, class-D, moving coil, LP, CD, streaming, MQA, MDF, power supplies, AC power, capacitors, shorting plugs, fuses, bass, cost, your listening room? Is your head spinning yet? If not—and possibly if so—you're an audio enthusiast! You thrive on conjecture, guesstimates, instinct, uncertainty, personal bias, vague science, and, above all, hope for a big sonic payoff. It's who you are, and it's why regular people can't be audio hobbyists. It would drive them mad.

Prior to this review, I had expectations about the product under review, the Leak Stereo 230 ($1695 with the walnut enclosure), based on, among other factors, price. Those expectations seemed justified when I first saw the Stereo 230's compact shipping carton. I assumed it would weigh much less than it did—28lb it turns out, heavy enough to cause my outstretched arms to buckle under its weight when the UPS guy handed the box to me. When that happened, my first thought was, "I hope he didn't notice," followed by, "Is the Stereo 230's power supply that substantial?"

The Leak Stereo 230
Yes, it is. But first, some background. Leak was on the front lines of the audio revolution that begat hi-fi as we know it. Harold Joseph Leak founded the company in England in 1934, two years after the electric guitar was invented, two years before the BBC began television broadcasting, and five years after the start of the Great Depression.

Throughout the '40s and into the '60s, Leak manufactured amplifiers, loudspeakers, cartridges, turntables, and—perhaps more ubiquitously in North America—tuners, especially the Trough-line tuner released in 1955. Among Leak's other offerings were significant design "firsts": the first tube amplifier to lower harmonic distortion to 0.1% (footnote 1); the first speaker to implement true-piston cone technology. Production continued until 1979, when Leak succumbed to the pressures of international mass-market competition.

China-based IAG Group—owner of Luxman and a bevy of well-known English brands—revived the company by reinstating its design facilities in the UK. In 2020, the year that would've been Mr. Leak's 113th birthday, Leak's first new products in 40 years, the CDT transport and the Stereo 130 amplifier, were released. The 130 is a rejuvenated Stereo 30 from 1963, said to be the first commercially available solid state amplifier. The Stereo 30 put out 15Wpc. Jimi Hendrix owned one.

Launched two years after the 130, the subject of this review looks like the 130's twin, but it comes with higher aspirations. Per Leak's press release, the Stereo 230 is "the evolution of the acclaimed Stereo 130, offering more versatility, much more power, and improved sonics."

In an email, I asked Jamie O'Callaghan, global sales and marketing director for the IAG Group, how the 230 was fundamentally different from the 30. He responded, "We now have 50 years of technology, innovation, and learning to enhance the offering.

"One key difference," he wrote, "was the development of transistors over the last 50 years. The modern transistors are designed to offer higher efficiency. This alone represents a major improvement over the original 30.

"Another important change from the Stereo 30, and from the Stereo 130, is the 230's use of an intelligent 'double parallel' design in its power stage. It not only increases power output compared to the other models but allows for easier handling of difficult loads and low-impedance speakers.

"We also designed a precision DC Servo Circuit to control and stabilize the power amplifier's DC voltage, resulting in improved output quality, especially in the bass, and a clean and warm sound, characteristic of Leak."

What about that arm-buckling weight? "The power supply is heavy!" Jamie said. "Its transformer weighs 2.9kg"—that's 6.4lb—"and was made exclusively for the 230. We do not use off-the-shelf products. It's a staple of our class-AB design—the transformer is key to it all. But, naturally, a lot of the 230's weight can also be attributed to its chassis and [optional] casing. It's a real wood veneer and a real wood casing, similar to the Wharfedale Linton's cabinet." Wharfedale is also an IAG brand, along with Quad, Mission, and a couple of others.

The 230 combines old-world features—a phono stage, headphone jack, and tone controls—bunked alongside new-world ones that were half a century into the future when the model first came out. These include hi-rez streaming up to 32/768 PCM, native DSD512, and full MQA decoding. Digital processing is handled by a 32-bit ES9038Q2M Sabre Reference DAC chip using proprietary circuitry said to make the most of ESS Technology's Hyperstream II architecture and Time Domain Jitter Eliminator to eliminate noise and improve high dynamic range. The 230 is also "Roon Tested," meaning that Roon verified that the product works with Roon's management software but, in contrast to Roon Ready products, does not use Roon's RAAT streaming protocol.

The Stereo 230 is also equipped with aptX HD Bluetooth and HDMI ARC connectivity (for use with a television). Its amplification stage is a MOSFET-based class-AB design said to deliver 75Wpc into 8 ohms or 115Wpc into 4 ohms. (We'll see what JA's measurements say.)

Why not class-D, which is popular now, even in retro products like this? "Class-D offers many virtues, but it's just not Leak," Jamie said. "The Stereo 230's baby sister, the Stereo 130, was several years in development with a very stringent design goal of making sure that the ethos and soul of the Leak brand weren't lost in pursuit of building a modern amplifier. The 230 comes a good four years after Leak was revived within our engineers' labs. It's a genuine innovation for the company in terms of design, compatibility, and power supply, and it's still a 'Leak'. We don't believe that would have been possible to do in a class-D design."

Among the control knobs on the 230's faceplate is a direct-mode push-button, which bypasses the tone controls. I found the input selector smartly constructed. Active inputs are flanked by a dotted light that confirms input selection and blinks when the volume is raised or lowered via the nicely finished, slablike remote control.

Encased in the optional walnut enclosure, I found the 230 attractive in a timeless way.

Listening
The Stereo 230 arrived brand-new. If I was expecting the unbroken-in Leak to deliver a flat, harmonically meager sound compared to that of my $15,000 class-A Shinai integrated—well, that's not what I heard. What initially knocked me back in my seat in a moment of unexpected incredulity was the depth and integrity of the soundfield. It was architecturally molded.

Granted, I was playing an audiophile CD—Contact (Fidelio FACD 001) by Art Johnson and Frédéric Alarie, an analog recording of double bass and an electric guitar, captured by gear bearing the names Ampex, Tascam, Nirvana, and Transparent. It's meant to sound intimate, pure, resolved, natural. Fresh out of the box, the Leak brought that sound out. I had only wanted a taste of the Leak before putting it through its break-in paces—with zero intention of judging it—but judge it I did, because what I heard caught me unexpected.

As soon as the album's first track kicked in—Stevie Wonder's "You Are the Sunshine of My Life"—I was peering down a room transposed into my own: the recording studio. It stretched quite a bit beyond my own room, about 25' deep, judging by the acoustic reflections delineating its shape. Alary's double bass sounded well-proportioned and hearty in tone and low-end weight. To borrow the title of an album by The Who, the low notes and their rhythm were meaty, beaty, big, and bouncy. And that guitar! String tones sounded realistic, not just in big-scale character but in how their smallest shifts revealed varying states of string tension. The curlicues at the end of notes were appropriately twangy, steely-resonant, and spatially carved-out.

Listening to Contact, even in these early hours, brought to the fore how fluid and coherent the Leak's sound was. There was nothing hard or choppy. Its tonal balance tended more toward sweet than warm. I heard no frequency-response bumps, just an overriding naturalness of timbre and a bloomlike roundness to the notes.

But what spoke louder than any word I might find to describe the Leak's sonic attributes was the about-face of my intentions for the day. What I expected to be a 3-minute casual audition turned out to be two serious, 30-minute auditions the day I turned it on for the first time, sessions that ended up being written about in this review. I was expecting sound from an unbroken-in, $1695 solid state amp to grate. Another expectation bites the dust.

Three days of continuous break-in later, I settled in for official business. I dropped the laser on Tord Gustavsen's "At Home," from his 2007 album Being There (CD, ECM B0008757-02), and was greeted by a carousel of piano tones endowed with just the right amount of string-felt jangle, sultry efflorescence, soft-colored hues, and finely measured force. Decays seemed elongated. Again, as with Contact, I heard a mellifluous musical delivery, an evenness to the presentation coupled with a rhythmic pace that was poised and self-assured. When the drums and double bass joined the piano, the picture was big and wide, with life-sized instruments living inside. But most of all, it sounded utterly cohesive. The soundfield was a unified, meticulously sealed whole.

The Leak's overriding character was one of musical buoyancy disposed of light and color, with an effortless liftoff of notes. It was uplifting psychologically. The effect was mood-altering. At $1695, it's good for a few therapy sessions.

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Footnote 1: This review triggered memories, as my first exposure to high fidelity (albeit in mono) was in 1964, in the English equivalent of High School. We had weekly music appreciation classes, with LPs played back via a Leak Point 1 amplifier and a Leak Sandwich loudspeaker.—John Atkinson