Karan Acoustics

POWERa Mono Power Amplifier

£89,995 RRP (pair)

Established in the summer of 1986 by Milan Karan, the Novi Sad, Serbian-based outfit Karan Acoustics originally specialised in the servicing and maintenance of complex medical and TV broadcasting equipment. A passion for music steered the company towards the design and manufacture of high-end audio components, culminating in the company's debut hi-fi product being released in 1989. Since then, it has focused on making state-of-the-art solid-state audio electronics, striving for the highest fidelity.

The new Master Collection POWERa monoblock continues this trajectory; a pair costs a cool £89,995, for which you get an immense 2.1kW of power per side. The pinnacle of the company's lineup, it's a monstrous thing in the flesh – each measures 504x292x603mm (WxHxD) and weighs 105kg! As you would expect, the amplifier is delivered in industrial-strength wooden crates; it's at least a two-person job to move out of the crate and into your preferred position for use. Karan Acoustics recommends the use of dedicated amplifier stands to support this unwieldy mass.

The chassis design is striking; finished entirely in aluminium, it has a glass black fascia inside of which is a red illuminated Karan Acoustics logo. A solid CNC-machined piece of aluminium is used as a single-piece unibody heatsink for the output devices, negating the need for obtrusive heatsink fins or active cooling. All Karan Acoustics products are underpinned by three CMS CS2 supporting feet, ensuring minimal vibration transmission between the components and the surface they rest on.

Rated at 2,100W into 8 ohms – and with a claimed 6kW into 2 ohms – this is not your everyday power amplifier. Gain is put at a fairly high 30dB, so care must be taken level matching when adding this amplifier to an existing multi-channel system. The quoted frequency response is 20Hz to 20kHz (+/-0dB), signal-to-noise ratio is put at >120dB, and THD is 0.03% – all excellent figures.

Operating in Class A mode, this amplifier is DC-coupled with no capacitors in the audio signal path to compromise sound. Karan Acoustics' products are grounded in solid-state technology, using cutting-edge Ring Emitter Transistor (RET) bipolar output devices operating with zero overall feedback. Quality is said to be paramount: “We use only the highest-grade, custom-made components. The electronic boards are meticulously designed, featuring 75um and 105um copper layers for optimum performance. These are decoupled using custom-engineered mechanical parts, eliminating feedback from the unit chassis.”

Each POWERa features two large toroidal power transformers, rated at 2.7 kVA. This unique setup requires two IEC 15A plugs at the back of each amplifier for power supply. An in-house designed Line Conditioner is built in, claimed to eliminate unwanted DC components in the mains supply. According to the company, the latter can cause mechanical vibrations and resonances in the mains transformer cores, seriously impacting sound. It is possible to manually disable this via a switch on the back of the unit. The power supply has 210,000uF of capacitance. Karan Acoustics notes that it has “minimal internal impedance with large capacitance reserves for ample dynamic headroom.”

Powering up this amplifier is a hands-on process, as there's no remote control or trigger cable input available. Karan Acoustics suggests initially running it for at least one hundred hours to get both passive and active components performing at their peak. The manual advises allowing sixty minutes for the amplifier to warm up and reach optimal performance but does not recommend leaving it on all the time. A five-year parts and labour warranty comes as standard. I streamed hi-res audio from Qobuz using Roon to evaluate these power amplifiers in my system. An MSB Premier DAC acted as a preamplifier, and my reference pair of JBL K2 S9900 loudspeakers were used.

THE LISTENING

As a daily user of large monoblocks – in my case, McIntosh MC1201s – I am familiar with the benefits of large dynamic headroom, and the POWERa underlined them. It proved to be the most impressive monoblock I've had in my system to date. There is no hint of distortion or compression, even when pushing the outer limits of my loudspeakers – and my ability to stay in the same room at such punishing volumes. This amplifier sounds highly visceral, but it's not at the expense of accuracy or transient response; it has tremendous immediacy that is hard to live without once you've experienced it.

Whether you're listening to finely recorded classical, driving rock or expansive electronica, the POWERa never breaks into a sweat. Able to retrieve intricate detail from within an immense soundstage, it draws out acoustic treats in a delicate manner. Although happy to play along beautifully at lower volume levels, when you open up the throttle, you're rewarded with near-limitless power and an amazing wall of sound that's both crystal clear and highly musically articulate. 

For example, the indie rock of bdrmm's It's Just A Bit Of Blood uses the total width of the soundstage to create an enveloping sound that skilfully avoids the compression that lesser amplification invariably delivers. While pretty in the quieter sections, this song really gets into its stride when the guitar strumming ramps up, with discordant harmonics playing off one another and surfing the soundstage. 

Grian Chatten's Fairlies is a wonderful slice of folk rock, embedding sharp hooks with a singalong chorus. Powered by the Karan Acoustics monos, the rolling rhythms of the track tether some impeccably recorded vocals. With a light dusting of reverb and some dynamic acoustic guitar playing, the track is a right-foot thumper. At moderate listening volumes, the POWERa creates an intimate and enjoyable listening experience, but when the mood hits and the volume is kicked up, the insistent liquid bassline and infectious vocals become more prominent and immediate. The folk-inspired wigout that finishes the song gains intensity and drive that is missed on lesser systems.

XTC's Summer's Cauldron opens the band's Skylarking album with a lovely pastoral background and singer Andy Partridge's plaintive vocals. As the song progresses, bird and insect noises track across the soundstage; via the POWERa, their presence proved more engaging and less grating than expected. As the percussion broke in, I was surprised by the speed and ease by which these amplifiers made the 15” woofers in my big JBL loudspeakers dance. Knowing this song intimately, I was also struck by the width and depth of the soundstage. This beguiling mid-eighties track sounded especially refreshed via the Karan Acoustics monoblocks.

Marc Almond's peerless collaborative cover of Gene Pitney's Something's Gotten Hold Of My Heart sounded sublime through the POWERa amplifiers. The singing demonstrated this amplifier's amazing control, and the percussion work was wonderfully tangible and visceral. Even at modest volumes, the push and pull of these two great singers created a palpable tension that the Karan Acoustics made utterly engrossing to listen to.

This vice-like grip extends down to the low frequencies, as well. Autechre's Kalpol Introl might be thirty years old this year, but via the Karan Acoustics, the listening experience was transformative. Masterful electronic composers, Booth and Brown layer sampled percussion and fat analogue synths with total precision. The ease with which the POWERa amplifiers let the bass and sub-bass tear apart the mix was quite something to hear. The result was captivating after giving the amplifiers more volume – with even better detail and texture becoming apparent.

Exodus by Noisia and KRS-One is an explosive track that tests the limits of any serious hi-fi system, and the review pair of POWERa monoblocks delivered here in spades. The sound had incredible dynamics, coming across in equal parts violent, visceral and forceful. The contrasts in levels experienced in different sections of the recording were simply mind-blowing and, I imagine, dangerous to my long-term ear health. Compared to the Mark Levinson ML50 amplifiers I reviewed recently, I could sense the compression of the audio when pushed to the limit, but not so with the Karan Acoustics.

THE VERDICT

Karan Acoustics' new flagship monoblock power amplifier is astonishingly capable and raises the bar for the competition. It can push insane amounts of power into any loudspeaker, regardless of its sensitivity or load characteristics. It has great rhythmic alacrity, firecracker dynamics, and vast tracts of bass driving power, yet is precise, articulate and blessed with unerring accuracy. Whatever the sound pressure level the listener requests, the POWERa does not so much as blink, let alone break into a sweat.

That is why, despite the extremely high price, I firmly believe that this pair of monoblock power amplifiers represents true excellence – you certainly pay a lot, but you get a lot back! It's for those seeking playback perfection, and the POWERa is a true endgame goal. If you seek the pinnacle of modern amplification perfection, then look no further – you've just found it.

For more information visit Karan Acoustics