Copland CTA407 Integrated Tube Amplifier Review

Posted on 6th April, 2023

Copland CTA407 Integrated Tube Amplifier Review

Craig Joyce gets a warm glow from this special-sounding Danish integrated amplifier…

Copland Audio

CTA407 Integrated Amplifier

£6,500 RRP

Copland CTA407 Review

In the ever-evolving world of audio technology, it is a rare and soul-stirring experience to encounter a new device that harkens back to the golden age of sound. The Copland CTA407 integrated amplifier purports to deliver timeless analogue warmth alongside modern technical precision in a simple, single-device footprint. But does this harmonious marriage of old-world charm and cutting-edge innovation strike the perfect chord?

UP CLOSE

Copland Audio is a high-end audio equipment manufacturer based in Denmark. Before founding the company in 1986, Ole Møller began his career in the audio industry working for the well-known Danish audio manufacturing company Ortofon. After developing a passion for vacuum tubes, he recognised that modern technological advancements offered opportunities for fresh design concepts. As a result, his company's amplifier lineup aims to provide groundbreaking designs that were previously unattainable for earlier generations of tube amplifier engineers.

Copland's philosophy embraces minimalism and a robust industrial design. Recently, the company has simplified its offerings, mainly focusing on the CSA series of Copland Synectic Amplifiers – hybrid designs that incorporate tubes alongside solid-state circuitry. However, the CTA407 – which is the only model in the Copland Tube Amplifier lineup – boasts a tube output stage with impressive power. The amplifier's push-pull design uses a pair of matched power valves in a fixed ultra-linear configuration. According to Møller, this method improves performance by combining the low distortion qualities of triodes with the power of tetrodes.

Copland CTA407 Review

Copland's use of tubes is not aimed at painting the audible canvas any differently from traditional solid-state approaches. Møller says that it has never been his intention to obtain a specific sound related to the use of tubes: “Fine amplifiers can be designed with tubes as well as solid-state. While listening, you should not easily recognise which method of design has been used.” He states that using a pair of 6550 or KT-family tubes in a push-pull configuration can produce more than 100W of audio power. Additionally, the highly biased design allows the amplifier to deliver most of its power in Class A.

Although the CTA407's form factor is slightly taller than most integrated amplifiers, its controls and finish exude sophistication. The front panel features two high-quality rotary dials, one for input selection and the other for volume control. The motorised volume control is smooth and well-balanced. A rotary encoder selects inputs, with a blue LED on a wheel indicating the active input. The CTA407 includes 4x KT88, 2x 12BH7, and 1x ECC83 tubes and measures 435x215x390mm [WxHxD] with an approximate weight of 25kg; the presence of three toroidal transformers inside helps explain the latter!

Copland CTA407 Review

LEDs are used for each of the four power tubes within the amplifier, denoting the fact that they are warmed up (blue LEDs) and in serviceable order (a solitary green LED). When the tubes exceed 20W while playing music, orange LEDs illuminate, offering a unique VU meter display that adds an engaging element to the listening experience.

Traditionally tube amplifiers need manual adjustment of their bias voltage to ensure that the currents through the power tubes are balanced and consistent with the electrical operational points the amplifier has been designed for. The CTA407 employs intelligent bias adjustment, with each output tube having its own dedicated bias circuit. Throughout its lifespan, the amp constantly monitors the status of the power tubes and automatically adjusts the bias voltage. This approach ensures trouble-free usage and optimises sound without relying upon manual adjustments.

According to Copland, the tubes undergo a ten-hour burn-in process at the factory prior to shipment. After an additional day of usage in the CTA407, they're considered fully settled and burned-in. The 'soft' startup procedure, which takes about a minute, guarantees that each stage of the amplifier is powered on in the proper sequence, regardless of ambient temperature or the current charge status of the power supply capacitors. Møller estimates that the tubes should have a lifespan of at least 4,000 hours, assuming the amplifier is turned on and off several times daily.

Copland CTA407 Review

Five line-level inputs are offered, plus a tape monitor loop and an integrated phono circuit. Due to space constraints within the chassis, all inputs are single-ended (RCA) connections. The rear of the unit houses gold-plated brass speaker terminals with taps for 4 ohm or 8 ohm operation to best suit the connected speakers' impedance. The phono stage is moving magnet only, utilising a J-FET gain stage with active RIAA equalisation and over one hundred discrete components. Møller explains that it was not feasible to incorporate a DAC or streamer inside the chassis without compromising the amplifier's quality.

For this review, I ran a high-definition audio stream from Qobuz via Roon through my MSB Premier DAC. For analogue playback, a Technics SL-1210GAE/Ortofon 2M Black vinyl front end was used. I listened to all sources using a pair of JBL K2 S9900 loudspeakers.

THE LISTENING

The Copland provides an outstanding listening experience across a variety of music genres. Its ability to reproduce acoustic and electronic music is impressive, delivering powerful dynamics, intricate soundscapes and captivating vocals. It handles complex arrangements effortlessly, maintaining clarity and offering a broad soundscape that never feels crowded. Navigating through intricate compositions with ease, the amplifier maintains a well-defined and expansive audio landscape that never feels congested. Low frequencies are rich and smooth, while higher range percussive elements remain sharp and defined. The amplifier appears to bring warmth and emotion to the music, making every listening session an immersive and engaging experience.

For example, in Volcano Choir's first album Unmap, the track Still showcases post-rock production methods applied to a more traditional, acoustic sound; the song features a deconstructed and reassembled acoustic arrangement. Justin Vernon's voice is pitch-shifted tastefully, transforming into a textural element. A solitary droning organ tone sets a foundation which is enriched with sampled strings and effects before guitars and percussion propel the song along. The mix maintains a wide soundstage that consistently expands without collapsing. The track is emotionally captivating via the Copland, with the closing timpani surge demonstrating the amplifier's ability to render a remarkable dynamic range.

Copland CTA407 Review

The Acid's melancholic sound is beautifully rendered through the CTA407. This computer-based music is rich in samples and effects that create an engaging listen. In the track Animal, the bass lines flow smoothly and effortlessly, with the Copland handling the demands of my JBL's 15” woofers with ease. The snare hits are impressively large, and their reverb tails are precisely illustrated within the soundstage. RY X's vocals have a similar quality to frequent Burial collaborator Thom Yorke's, and the stereo panning and verse doubling, along with electronic percussion and a powerful bassline, captivate the listener.

The CTA407 has a lovely tonal quality that makes listening to harpsichords special. Four Tet's Two Thousand and Seventeen showcases an aggressive sampled harpsichord that sounds most impressive. As I really turned up the volume, some pleasant tube compression emerged, accompanied by glowing orange LEDs, while the captivating melody filled every corner of the room. Even at higher volumes, the top panel's ventilation proved adequate, with the CTA407 only getting warm during prolonged listening sessions. The high 93dB efficiency of the JBL speakers let it fully flex its capabilities as the volume increases.

Copland CTA407 Review

This amplifier is highly adept with timing, as Grace Jones's brilliant reimagining of David Bowie and Iggy Pop's Nightclubbing shows. This production triumph features the unparalleled rhythm section of Sly and Robbie, with meticulously crafted stereo imaging bouncing all around. The CTA407 expertly renders the sharp snare hits and delivers smooth, sinewy bass lines. Assertive guitars are perfectly syncopated with all this, and vocals are seamlessly carried.

Ghosteen is undoubtedly the zenith of Nick Cave's vast career, with the epic closing track Hollywood standing out as the highlight of this remarkable album. Listening to it via the Copland will send shivers down your spine. Warren Ellis's synthesised effects, coupled with Cave's piano and grandiose lyrics, leave you rooted to your seat, awestruck. A menacing bass line pulses throughout the piece, creating an atmospheric foundation with minimal percussion. All of which underlines how natural sounding this amplifier is; it's highly revealing without sounding processed. Think of it as a precision conduit connecting artist to listener.

Copland CTA407 Review

Via the moving magnet phono stage, this amplifier shows off its excellent timbral resolution. For example, the processed piano samples in Plaid's Missing give way to a foundation of strings and bass as sampled vocals weave through the mix. This beautiful music, carefully crafted into a cinematic soundscape, evokes memories of their soundtrack compositions. The piano samples are potent and focused – sounding slightly bright via my speakers, as I expect from their compression drivers. Although the phono stage doesn't possess the richness of my usual Manley Chinook tube preamp, it's important to remember that the total cost of the Copland is significantly lower.

THE VERDICT

The Copland CTA407 integrated amplifier skilfully blends the timeless warmth of tube technology with cutting-edge engineering precision, offering an extraordinary listening experience across diverse musical genres. With its thoughtful design, robust construction, and advanced features like automatic tube biasing, it ensures consistent and reliable performance. Perfect for both veteran tube enthusiasts and newcomers, it bridges the gap between classic and modern audio equipment.

For more information visit Copland

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    Craig Joyce's avatar

    Craig Joyce

    With an engineering degree in digital signal processing and a storied career in IT networking and cyber security, Craig loves to push the boundaries of audio technologies. An aficionado of live music with personal detours in music production and event promotion, Craig is a long time enthusiast of post punk, electronic and experimental music.


    Tags: copland  absolute sounds 

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