The secret of the Neodio amplifiers’ inherently musical qualities lies in their balanced design. That’s got nothing to do with the fact that it’s equipped with XLR inputs or whether it uses symmetrical circuit topology (it doesn’t). In this case it is to do with balancing the size and complexity of the different parts of the circuit. If we take the transformer as an example, it needs to be big enough to maintain the reservoir capacitance without sagging under load, but any bigger than that and it starts to eat the budget that needs to be spent elsewhere. Likewise, simply overbuilding elsewhere comes with real performance costs and a direct impact on value. Huge power supply caps need to have their sluggish delivery off-set by (inevitably expensive) bypass capacitors. Doubling up output devices can cause more problems than it solves. In each case, the essential infrastructure to mitigate the downside of such steps eats even further into the design budget. Simple, well-executed engineering is the order of the day, with clear design priorities and a brief that extends to the mechanical as well as the electrical aspects of the design.
On the face of it and in this Class D day and age, a bulky, full-width chassis and a chunky 14kg weight might seem like overkill for an 80 W/ch amplifier, flying in the face of material efficiency. Sure, even retaining the linear power supply, you could cram it into a box maybe one third of the size, but that would in turn seriously undermine one of the essential goals behind the design. Look inside the HQA and you find the dual-mono circuit laid out on a substantial PCB that occupies all of the space not colonised by the chunky transformer. That allows for well-spaced components, many of them discrete, with a circuit that it’s easy to trace – and thus repair should it ever fail. These are mainly conventional components: specially selected but ultimately replaceable for value and function if not type. So any competent service engineer should be able to look at (and fix) this amplifier, long after I’m dead and gone.
But being big gives also gives the circuitry space to breathe. That translates to thermal stability, a reduction of thermally related distortion mechanisms and lower levels of component interaction. The socketry is suitably minimal, with single pairs of RCA and XLR inputs and 4mm sockets for the outputs. These passed from popularity decades ago, replaced by glitzy binding posts that also accepted the spades demanded by global markets and certainly looked more impressive. But those of us with longer memories and who have ever done the comparison, know that those prosaic looking 4mm banana sockets sound as good or better than all but the very best (and most expensive) binding posts.
Old fashioned – but in a good way…
It’s a design choice that encapsulates and sums up so much of what the Neodio HQA is all about: Nothing flash, nothing extraneous; just simple, clear priorities, an uncluttered signal path and an appreciation of those aspects of mechanical design and component selection that help sound quality but have got lost in the high-tech wash.
