Giving Evo its Voice

As an all-in-one system, Evo is more than the sum of its parts – but it’s also very much comprised of a collection of components that are carefully designed and selected to get the best possible sound.

Everything, from the 4^th generation of StreamMagic to its preamp stage, makes sure Evo delivers the Great British Sound Cambridge Audio is known for – as the artist intended their music to be heard, with nothing added, nothing taken away.

We spoke to Sam Smith, Electronics Engineer at Cambridge Audio, about designing the preamp for Evo and how we voice products as part of the development process.

For those who might be new to hi-fi or have never owned separates like a preamplifier… what does one do?

A preamp takes the weak audio signal and conditions it before it reaches the main amplifier stage. When you change the volume on the front panel, it’s the preamp stage that is altering the level of the signal. It’s therefore very important that this stage is well-designed, and free from distortion and noise.

How did you design the preamp for Evo?

When designing the new preamp for Evo we had sound quality in mind throughout. We’ve always found that the preamp stage can greatly affect the sound quality of an amplifier and we went to great lengths to ensure digital and analogue circuitry were perfectly matched to the Hypex Ncore power amp module to ensure we retained the Cambridge Audio sound signature.

We painstakingly switched out components one at a time to make sure that the preamp stage worked together with the Hypex module to deliver Great British Sound. This is known as voicing. Only once our listening panel was happy with every aspect of the sound did we sign the product off for release.

Evo was voiced in London over hundreds of hours of listening tests… can you tell us a little more about the listening panel? Who takes part?

We have a number of people who are experienced in listening; they’ve been with Cambridge Audio for a while and know our sound. We have trained listeners as well, mostly from the Engineering team. Fundamentally, at Cambridge Audio we all love hi-fi, so it’s good to have different departments take part too.

So how does a listening test work?

We’ll start off by level-matching units and making sure the sound pressure level is the same across products.

We test products blind, so there’s no bias. The units are hidden – we don’t make people wear blindfolds! – so listeners don’t see them at all, and we’ll do A/B comparisons against a variety of different amplifiers. For Evo, we used the CX range as a good benchmark to try to get as close to as possible.

Thanks for speaking to us, Sam!