Martin Colloms

The development of this completely new power amplifier has been a major undertaking for Naim. Up to now, its designs have been variants on the late Julian Vereker's founding concept, which led to the first NAP 250 stereo chassis some 25 years ago. Even now, the company's biggest current model, the NAP 135, is a monoblock variant of the '250, with more generous power supplies allocated to the separated channels.

In late 1995 an idea began to take shape at KEF Audio. The company had already produced some fair-sized 'reference' models, culminating in the well-regarded Reference Four. But even this powerful and accomplished design lacked the necessary weight and presence to make a major impact at the highest quality level of world loudspeaker sales. So research began to define the key elements of what was intended to be a much larger speaker system, a definitive engineering expression of the company's knowledge.

During the preliminaries for this review I suffered a major blow at around 3am one morning [writes Martin Colloms]. I was woken up by a thundering roar from the listening room that sounded like a door being smashed down by men with sledgehammers and which wrote off a number of drivers in the speakers.

The long awaited Carver Cube power amplifier is at last available in the UK. Bob Carver, its designer, is not a particularly well known figure in the UK but most people have heard of Phase Linear, which was founded by him, and he also designed its range of products. His special interest has been in high-power amplifiers, with the 400 B and 700 B Phase Linear models now audio legends.