This is met and matched by the Lindemann musicbook: 55. This is a 240W per channel amplifier with balanced and single ended inputs. The amp is designed to be bridged to deliver 450W in mono mode should you require an upgrade, all packed into the same ¾ size amplifier chassis. How this is possible comes down to the letters ‘UCD’, short for ‘Universal Class D’ amplifier module.
Lindemann’s manual is an exercise in making the fairly complex task of putting a network streaming system together read like it’s not a problem. This doesn’t mean it hides things from prospective owners (resulting in a lot of headscratching and panicked phone calls and emails). Instead it guides you through the usual set-up procedure and offers some semblance of legitimate help should things go awry. This comes down to Lindemann building a digital front-end that doesn’t require a secret-service codebreaker to configure, and to a clean and logical layout of the manual. If you can follow the instructions to set up a TV or cook a meal, you can install the musicbook: 25.
There are even scaled down versions called the musicbook: 20 and musicbook: 50. The musicbook: 20 network player is basically the musicbook: 25 without the CD drive, while the musicbook: 50 is an 80W per channel, non-bridgeable Class D amp in the same musicbook: 55 chassis. In fact, the musicbook: 50 came before the musicbook: 55 in the development cycle, and the bigger, more expensive amplifier came about as a result of pushing the 80W musicbook: 50, which sometimes has difficulties driving low-impedance loads. The musicbook: 55 is an engineer’s creative response to just criticism; unless you are trying to drive a pair of old Apogee Divas or welding together parts of a battleship, you’ll rarely need more than a musicbook: 55.
Not that the ProAc Response D20R is what you’d call a ‘difficult’ load. The D20R is a simple eight-ohm load and has a sensitivity rating of 88.5dB, explaining why ProAc frequently demonstrates this loudspeaker with a Naim SuperNait in the UK. The D20R is essentially a variant on the extremely popular ProAc Response D18, replacing the 17mm dome tweeter with a custom-made 60mm x 10mm ribbon tweeter in the same offset position as in the D18 (which still remains in the catalogue). The D20R keeps the same 165mm fibreglass weave mid-bass cone, with a phase plug and what ProAc refers to as its Excel magnet. In re-evaluating the D18, ProAc took the opportunity to rework the crossover network and remodel the bass loading – the port still fires into the floor, but the construction of this system has changed, giving the loudspeaker a more graceful bottom (something we can all appreciate) and making it easy to install in a wide range of listening rooms. ProAc also experimented with a new white finish in time for the Bristol Sound & Vision Show in February, and was surprised by the uptake, so now these classic loudspeakers are available in a tidy shade of pure white.
Whatever the colour of cabinet, I admit that this would never have been a combination of products I would have thought of putting together. There is no real reason for saying this; there are no obvious incompatibilities, and there is nothing up with using the electronics from one European country with the loudspeakers of another. It’s just that there are so many possible permutations and combinations of products that this one would have taken years to fall upon. But having heard it, I’m awfully glad that someone did fall upon it.
This system brings together much of the convenience of Sonos with almost Apple-like levels of design and operation, and yet does so without sacrificing the sound quality in the process. Traditional audiophiles have their personal Rubicon to cross with Class D, and some will never make it. If you view it as just another form of output device, you’ll fairly quickly find Class D falls into three broad sonic signatures; too warm, too bright, and ‘goldilocks’. The ‘goldilocks’ point is all too rare, with just a handful of top-class brands enjoying the sweet spot. Well, now, you can add Lindemann to that select list of those getting Class D intrinsically right. This, coupled with the subtle performance of the ProAcs, works wonders.
Taken as a system, it’s got a hugely graceful sound, with outstanding dynamic range, great bass and super-accurate midrange. It’s one of those systems that never draw attention to their performance, and that is its greatest strength. In ‘doing a Yoko’ (breaking up the band), it became clear that this was also a common strength in all three components – the musicbook products reminded me of Primare’s understated, yet intrinsically ‘right’ presentation, and the ProAc’s overall balance just invited you into listening to the music and kept you there. Once again, the ‘goldilocks’ point springs to mind.