The Chord Mezzo 140 Power Amplifier

Two’s Company...

Anyone with experience of Chord Electronics’ DAC 64 will know that, despite their compact dimensions, the company’s Aspire series are extremely serious products. Even so, it’s hard not to find the “L” word clouding your perceptions. Yes, that’s the one – “Lifestyle”: small, stylish components where, if form doesn’t actually outweigh function, it definitely pushes to the front of the queue. Add a rather fetching lightshow and, in an industry where utilitarian looks are almost a sonic badge of honour, one can understand a degree of skepticism.

While compact size and unique styling are clearly high on the list of design priorities, the governing rationale goes a little further. The Aspire components are intended to answer the needs of audiophiles living in reduced circumstances –in spatial terms at least. High-end haven Hong Kong is just one example of a prosperous city where even the most luxurious accommodation tends toward the compact. So, the original Mezzo 50 amp was a stylish solution to driving speakers of moderate efficiency in small spaces. The bridging facility for increased output adds extra versatility, along with a loss-less upgrade path and the ability to grow into medium sized rooms. But what if your room is larger still or, more likely, your speakers don’t present that cuddly a load?

Enter the Mezzo 140. Sharing the same frontal dimensions as it’s smaller siblings, but with twice their depth, the 140 is unmistakably a member of the Aspire family, a fact underlined by that familiar violet glow emanating from the crenulated window in the unit’s leading edge. It too is bridgeable and it was to a pair of mono-blocs that I spent most time listening. On the top panel, twin circular indents reveal chromed inserts which, by accident or design, are suggestive of toroidal transformers. In fact, nothing could be further from the truth: not only does the 140 feature switch-mode power supplies, but there are four of them in each chassis. Seasoned Chord watchers will know that power supply topology defines the brand even more than their arresting visuals. Persistently controversial, there’s no ignoring the fact that switch-mode units should deliver energy much more quickly than the 50 Hz recharge cycle of a conventional PSU. To maximize this advantage, as per standard Chord methodology, the 140’s four units also fire out of phase.

If the Mezzo 140 has the potential to bridge the gap between Chord’s Aspire and SPM ranges, particularly with regard to mastering tricky speaker loads, then the obvious review scenario was…a tricky speaker load, here in the form of the Martin Logan Prodigy. While Martin Logan’s own amplifier recommendations go as low as 50 watts per channel, in reality these large hybrid electrostatics have a seemingly insatiable hunger for current. The key issue is not the sub- 1Ohm impedance of the panel at high frequencies but rather, the challenge of gripping the moving coil bass driver sufficiently firmly to subjectively match the speed of the panel in the cross-over zone. Failure in this respect manifests itself as an overtly “hybrid” sound, while success provides a wonderfully seamless blend of electrostatic transparency and moving coil heft.

The main review system consisted of a Great Northern Sound Company “Statement” modified Wadia 270se and 27ix pairing, directly driving a pair of bridged Mezzo 140 via the DAC’s digital volume control. Initial listening indicated that the Chord amps were a touch happier mounted on Seismic Sinks than when placed on either glass shelves or directly on a solid wooden floor. There also seemed to be a slight increase in overall coherence when the source was powered from my dedicated Kimber spur, while the Mezzo 140s were connected to the house ring-main – as is generally the case. However, improvements were subtle enough to suggest that the Mezzo 140 is not overly sensitive to its environment – a potentially important quality in a component that may be required to blend into it’s surroundings, rather than dominate them from the expensive perch of an all singing, all dancing equipment stand.

As percussion and bass are both areas that can expose the Martin Logans compared to full-sized moving coil speakers, that’s where I started. I‘m not sure exactly where Mick Fleetwood stands in the pantheon of great drummers, but for me, his performance on ‘Go Your Own Way’ is a percussion master class. It might be the anguished melody of Lyndsey Buckingham’s vocal that first raises the track beyond mere hook-laden FM fodder but, listen a little deeper and the drumming creates an expressive rhythmic counterpoint. In turn, what the Mezzo 140 provide is an incredibly detailed timbral map of each drum skin, with the exact force and each strike’s point of impact clearly portrayed. During the final bridge, the sense of barely controlled angst and fury was utterly mesmerizing. If you think 75 EQUIPMENT REVIEW Rumours is a little, well, “middle of the road”, a listen via these Chord’s could be an illuminating experience.

Remaining squarely in the 70s, the introductory bass-line to Roxy Music’s take on ‘The In Crowd’ displayed leading edges of an almost percussive intensity, followed by note bodies of a wonderfully taut elasticity. Growth and decay were equally well-defined and, as I pushed sound pressure levels deep into anti-social territory, there was almost a sense of air being sucked back into the speaker cones as each note ended. As guitar and vocals joined keyboard and bass, the distinctive rhythm remained perfectly weighted while, even as the track ended in a veritable festival of feedback, a sense of total coherence remained. It takes a lot of drive for the Martin Logans to sound like genuinely credible rock speakers and, in this respect, the bridged Mezzos were highly successful, punching well above their 220 Watt weight.