Under the skin of Sony's STR-DA2400ES - chassis, sockets and solder

We had the Sony people in the other day, bringing the new STR-DA2400ES receiver. And while we haven't got round to giving the thing the full test workout - we don't do listening or viewing with the proud (and slightly nervous) 'parents' looking on - we have now had the full technical rundown on the receiver, which Sony clearly sees as one of its key home cinema products for this autumn.

In fact, along with the receiver came what European Technical Marketing Manager Eric Kingdon called a 'Technical note': some note, running as it did to 28 pages of A4 with copious charts and diagrams! But then that's Eric for you - it's indicative of how involved he gets right down to the nuts and bolts of a product.

Or, in this case, right down to the cutting out of little copper dampers to fit on the top of the main power supply caps, in the snug workshop area at the back of the main listening room at Sony HQ in Japan.

It's there he works closely with the Chief Distinguished Engineer of Sony's audio division, Takashi Kanai, who's developed more products than most of us will ever own, and is an inveterate tweaker, not to mention a perfectionist. And if you want to know how much of a perfectionist, this is what he does as a hobby.

Aiming for Onkyo?
Anyway, back to the STR-DA2400ES, which looks like it was designed with the aim of being Sony's Onkyo-beater, It sits above the STR-DG820 in the range, and has two more models above it, the STR-DA3400ES and STR-DA5400ES, the latter being something of a 6 HDMI in/2 out monster. But at £500, the 2400 is clearly very much the core product.

And the receiver comes fully loaded, not just with features but with typical Kanai/Kingdon design tweaks. The chassis, for example, is a fairly simple sheet metal one, but it's embossed in various places to aid rigidity without adding mass, and spread the load of heavy components such as the power transformer and heatsinks.

Off-centre screws
Also in place are feet with off-centre mounting screws – because they sound better, of course – while the solid aluminium front panel has a further sub-panel behind it, thus isolating the display circuitry, a potential source of electrical noise, from the receiver's audio circuits.

Even the heatsinks have been redesigned: they're big, they're heavy and they're even sculpted to damp out resonances.

All HDMIs are not equal
The circuit layout is kept as short as possible, both on the audio and video sides, and it's interesting to see that one of the HDMI inputs is labelled "BD IN (for AUDIO)". Now there's on for the 'digits is digits' brigade - surely all four of the HDMI inputs handle audio as well as video?

Well yes, explains Kingdon, they do - it's just that the BD input is closest to the HDMI switching in the receiver, and thus sounds better, he says.

Smarter solder
Oh, and finally, let's talk solder. Yes, solder. Sony, like other companies, has had to give up the use of solder containing lead, due to regulations on the reduction of hazardous substances in products. So it switched in 2003 to lead-free solder, choosing the one with the least detrimental effect on sound quality.

Even so, the effects were there, not least because the 'safe' solder sets with a rougher surface than the original, and high frequencies tend to flow better on the surface - the so-called 'skin effect'.

So Sony has now come up with its own audiophile solder, which is almost pure tin with just 0.7% copper to lower its melting point and thus restore the smooth surface. The result, the company says, is even better than the original solder managed, with "a natural, rich texture and atmosphere" and a more enjoyable sound with voices.

That's the kind of thinking that's gone into this receiver - a mixture of getting the features right and applying some good old-fashioned audio tweakery.

It'll be fascinating to see what the review team makes of it.

Andrew has written about audio and video products for the past 20+ years, and been a consumer journalist for more than 30 years, starting his career on camera magazines. Andrew has contributed to titles including What Hi-Fi?, GramophoneJazzwise and Hi-Fi CriticHi-Fi News & Record Review and Hi-Fi Choice. I’ve also written for a number of non-specialist and overseas magazines.