Small but mighty: How we managed to fit everything inside Evo

As an all-in-one system, Evo does a lot.

It has a suite of digital and analogue inputs, and by using our StreamMagic hardware and app, it can access music streaming services and internet radio alongside physical formats like record players. Even video sources can join in – just connect your TV’s HDMI ARC output to Evo’s ARC input.

Compared to a more traditional hi-fi build of separates, Evo doesn’t take up a lot of space – it’s one of the things that make it so good looking in your living room. But getting its form factor small enough, while offering great sound and connectivity at a fair price, wasn’t easy.

Francesco Bettucci, our Senior Electronics Engineer, spoke to us to explain how we managed to fit everything we wanted in Evo, and the main difficulties of designing all-in-one systems. 

Small but mighty: How we managed to fit everything inside Evo

First of all, what’s the biggest component you had to fit inside Evo?

The largest part of an all-in-one is the amplifier, so in order to make it compact, we had two choices: doing a small Class AB, but very low power, or move to Class D, which allowed for a significant reduction in space.

And as we know…

We went for the latter, and Hypex NCore. It's not cheap. This is a patented special implementation of Class D. And obviously, that adds a cost.  

But it wouldn’t be as convenient for the customer if Evo was bigger. The space available for hi-fi equipment in a flat is always less and not everyone wants a big unit. We wanted to make something easy to use, something relatively small and able to be placed pretty much anywhere in a house.

Once you have all of the pieces that you want to fit into an all-in-one, do they need to physically be positioned in a specific way relative to each other?

Yes! There are technical things to be considered, like reducing the noise inside the units. So the power supply should be as far as possible from the signal. 

Evo has a phonostage and that's very sensitive to noise – any kind of noise – so we specifically designed the digital board to act like a shield, so there are no pieces that could emit any noise firing down to the phonostage. That was a careful design choice to try to make it a silent as possible.  

We used many good design techniques to maximise the performance of Evo, like meticulously placing and shielding the antennas, so that they don’t radiate inside the unit and affect audio quality.  

We’ve talked about what’s inside the box. Can you tell me more about the case itself? How did we design it, and choose the materials?

The bottom, the top and the front are made of aluminium, which is generally very strong and avoids resonances. So the structure itself is very rigid and solid. We used thick panels to make sure that there are no vibrations in the unit, and it is isolated from external disturbances.  

The other thing we did is maximize the internal space by not doing rounded corners. And this also means we can fit more connectors on the rear panel.

Were there any features that we wanted to fit in that we just couldn't in the end?

No, that wasn't a problem. Using Class D helped a lot. And the mechanical design ran in parallel to electronic, so we could know the shape and the size, design the electronics accordingly and know they would fit then.  

Thanks for your time Francesco!