Sign in to follow this  
Alex 54

Leema Acoustics Tucana II Anniversary Edition

Recommended Posts

Posted (edited)

 

image.thumb.png.dfae41d5df31f702338aae0d82fe74ba.png

Leema Acoustics Tucana II

Anniversary Edition

By Alex Colburn

Introduction:

Leema Acoustics is a UK based manufacturer of high-performance audio equipment founded in 1998 by two ex-BBC sound engineers, Lee Taylor and Mallory Nicholls. Leema originally concentrated on loudspeaker design and manufacture culminating in their first product, the Xen micro monitor which was originally only available to the professional market. Following the success of the Xen speaker, Leema decided to expand into the audio electronics market and launched the Tucana integrated amplifier in 2006 to much critical acclaim. Since then, their electronic product range has expanded to include amplifiers, DACs, streamers, music servers, phono stages and analogue and digital cables.

The intervening years have seen the Tucana upgraded initially to the Tucana II and more recently to the Tucana II Anniversary Edition reviewed here. New features include, upgraded printed circuit boards with 2oz gold plated copper tracks (1oz is the usual standard) to reduce inter component track resistances, critical capacitors upgraded to Nichicon’s audio grade MUSE series, Noratel “extra quiet” low-noise toroidal transformers, precision matched output transistors and silver soldered Leema Reference 2 speaker cable between PCB’s and speaker terminals.

Description:

The Tucana is delivered in a necessarily robust cardboard carton packed in high density recycled foam packaging. Weighing in at a hefty 18kg, this is surprisingly heavy for such a compact integrated design. The case is predominately constructed from substantial machined aluminium plate and custom moulded aluminium finned heatsinks. Available in a silver or black anodized finish (heatsinks in both versions are black), the Tucana has the look and feel of a quality built product. All aspects of control can be achieved using the front panel but the amplifier comes with a weighty anodised aluminium IR universal remote control that will control all the current range of Leema audio products. Leema also build “LIPS” (their proprietary communication system) into their audio products so users can easily integrate other Leema products into their system. The user manual includes a comprehensive collection of certified test reports detailing results from tests carried out during each stage of the build process for an individual amplifier.

The rear panel sports nine pairs of gold plated RCA connections, six un-balanced inputs, a tape loop (fixed level output), preamp outputs and one balanced input (XLR). Potential users should note the right and left balanced inputs are located on the left and right sides of the amplifier respectively, the reverse of the usual orientation. Fully shrouded gold plated loudspeaker terminals that will accept 4mm plugs, spade connectors or bare wires are mounted at each end of the rear panel. Two proprietary “LIPS” connectors are provided adjacent to the centrally located IEC mains input. There is no phono input which some would expect in an integrated amplifier but this is simply a reflection of the recent trend towards stand-alone phono stages and indeed Leema cater for this market themselves.

image.thumb.png.473a352e0c7b26c989481def7226fdb9.png

 

The illuminated front panel power button toggles the amplifier between standby and on, there is no off condition. Leema recommend the Tucana is left in standby mode as it consumes minimal power and is essential for “LIPS” operation. Additionally, the Tucana will remember previous input and volume settings while in standby mode and restore the settings when powered up. The large volume control is of the rotary encoder type and rotates freely without click or end stops. A ring of 32 LEDs surrounding the volume control indicate the current gain setting; intermediate steps are indicated by adjacent LEDs being illuminated giving a volume setting resolution of 64 steps. Two LEDs below the volume control flash to indicate overload and thermal limit conditions which reset automatically when the condition resolves. An arc of 7 illuminated push buttons switch between inputs with an additional row of 4 buttons for GAIN, BALANCE, MUTE and TAPE selection. Pressing GAIN allows the volume of the currently selected input to be pre-set to +/-10dB of the master volume setting allowing the user to match sensitivities between inputs. Two 3.5mm jack sockets provide a high quality headphone output and a duplication of the MULTI2 input to allow the connection of MP3 devices.

Leema have put some considerable effort into designing the microprocessor controlled volume/mute control, I could not fault its efficiency in preventing me from potentially doing something stupid while switching sources.

 

image.thumb.png.24b36d93ef6f4c21fc704a0d292ea087.png

 

Technical discussion:

The design topology within the Tucana is that of “dual mono” from power supplies all the way through to power amplifiers, the mirror-image internal view shows that this also extends to the PCB’s and physical layout of individual components. Each channel has separate toroidal transformers, rectifiers and reservoir capacitors with a third transformer used to power the control electronics and effectively isolate digital from audio power.

Input switching is achieved using gold flashed silver contact relays controlled but a microprocessor, the signal then passing to high quality OP275 operational amplifiers. The buffered input signal is then passed to microprocessor controlled Burr Brown precision attenuators that function as the volume control. The attenuated signal is then fed to the power amplifier inputs.

The power amplifiers use a classical differential input stage feeding a constant current loaded class A voltage gain stage to drive a class B push-pull emitter follower output stage. To reduce output impedance and increase output current delivery, the output stage consists of three precision matched pairs of paralleled output transistors. Each stage has been optimised in line with the design philosophy of guru Doug Self with additional enhancements from the Leema designers.

Class B power amplifier designs should be reasonably efficient but the thermal design characteristics of the Tucana seem excellent, in normal use the case ran at 35˚C and despite several hours playing at high volume I was unable to get this up to more than 45˚C. The manual states thermal trip occurs at 70˚C but I cannot imagine any normal domestic situation where this kind of temperature will be achieved.

 

image.thumb.png.dd056d3666a523a4f66839b539f39034.png

 

Audition:

To avoid any possibility of source/amplifier interference, I used the fully isolated transformer output on my Linn Klimax DSM Mk 3 to drive the balanced inputs on the Tucana. Leema do not state a recommended “burn-in” period but the Tucana took several hours to reach optimal performance. With the volume set to maximum gain, an ear to a speaker confirmed the amplifier’s low noise specification.

Technical specs and pedigree were telling me the Tucana should be able to look after itself so I decided to throw it straight in the deep end and start by playing Jean Guillou’s rendition of Mussorgsky’s Pictures at an Exhibition on The Great Organ Tonhalle, Zurich. The Tonhalle instrument is one of Europe’s great organs with 32’ pipes housed in superb acoustics and is a challenge to portray on any HiFi system. Soundstage presentation was good producing an image with good breadth and depth, medium and higher pipe ranks could be located quite accurately. Reproduction of the Tonhalle acoustics was accurate and entirely believable. Despite the considerable power demands in the lower registers, bass delivery was tight maintaining timbre and with a seemingly effortless character.

Turning to orchestral music, The Atlanta Symphony Orchestra’s rendition of Gustav Holts Planet Suite conducted by Yoel Levi is my favourite performance of this piece. Mars was delivered with the power and authority you would expect, the strident brass was well integrated with timpani and string sections. Peaceful Venus was very good for demonstrating the woodwind section and Mercury the string section. The exuberance of Jupiter comes over well with good dynamics and instruments well separated in a detailed image. Saturn comes over with its full measure of dreariness, there’s not much more to say! Uranus is presented with great dynamics particularly from the tympani and Neptune simply speaks for itself. Overall the Tucana does a good job presenting orchestral music; certainly it would fit in nicely to a classical fan’s system.

Having just purchased Steve Wilson’s re-mastered edition of Porcupine Tree’s In Absentia in 24bit/96kHz, I thought this would be an excellent recording to evaluate performance on rock music. Wilson’s heavy guitar riffs on Blackest Eyes are a delight along with some dynamic drumming, snare drum was fast and rim shots hard and precise and cymbals shimmered nicely. Complex passages maintained instrument separation so individual threads were easily followed. Acoustic guitar sounded solid with great detail, individual notes starting and stopping with good timing precision. 

Cara Dillon Live at the Grand Opera House (24bit/48kHz) is an excellent atmospheric live recording of voice and acoustic guitar. Cara’s voice was crisp and natural sounding with no hint of the sibilance so often found on lesser systems. Piano notes had good attack with the timbre you would expect from a grand piano. Sound output from the bodhran extends from the upper bass to the mid range of frequencies and consequently challenging to reproduce but the Tucana achieved this with ease.

The headphone socket was auditioned using my Oppo PM-1 planar magnetic headphones with the supplied 3.5mm jack cable. Sound quality was generally good though not really powerful enough to drive the PM-1’s to decent volumes. This is a somewhat unfair criticism as the impedance of the PM-1’s is right at the lower recommended limit of 32Ω. I suspect the design is optimised for use with more efficient headphones intended for MP3 player use.

 

Conclusions:

The Tucana II Anniversary Edition integrated amplifier is available through an extensive network of UK dealers. Leema Acoustics offer a two year parts and labour warranty on all their products with an option to purchase a further three years. With a retail price tag of £4995 including VAT the Tucana must be considered a significant investment for the majority of HiFi enthusiasts but in view of its overall performance and excellent build quality it represents a good investment that is unlikely to disappoint whether they be a rock or classical fan. Highly recommended!

 

Technical specifications:

Output power: 150W RMS into 8Ω, 290W RMS into 4Ω or 520W RMS into 2Ω.

Total harmonic distortion: 0.004% @ 10W RMS 1kHz.

Frequency response: 5Hz to 100kHz +0dB to -3dB @ 1W

Signal to noise ratio: <-100dB @ 285W into 4Ω. 

Output impedance: 0.05Ω.

Damping factor: 160.

Output current: +/-50A.

DC offset: +/-50mV max.

Input sensitivity CD input: 565mV RMS.

Input sensitivity other inputs: 311mV RMS.

Weight: 18kg.

Power supply: 230V 800W Max.

Dimensions: 440mm wide x 320mm deep x 110mm high.

 

Associated review equipment:

Source: Linn Klimax DSM Mk 3.

Speakers: Modified Townshend Glastonbury Tor Mk1/Townshend Maximum Supertweeters.

Headphones: Oppo PM-1

Interconnects: Nordost Tyr 2 balanced XLR.

Speaker cables: Nordost Heimdall bi-wired Z-plugs.

Power cords: Nordost Heimdall II

 

Edited by George 47
  • Like 1

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.