Not so long ago the phono-stage was an integral (albeit central) element in every single serious pre-amp. But with the advent of CD the audio landscape shifted, and as vinyl fell from favour, designers were only too happy to dispense with the tricky and expensive necessity of providing onboard phono equalization and amplification. Pretty soon the phono-stage became first an optional extra and then a standalone purchase, turning turntables into linelevel sources like everything else – a step which naturally also added the cost of a dedicated power supply and casework to their price as well as adding another box and set of interconnects to your system.
But it wasn’t all bad news. Truth be told, a separate box is probably pretty much a pre-requisite for serious performance, as is an independent power supply. So, although phonostages became (in some cases, much) more expensive, they also started to deliver results that previously we’d only ever dreamed of. And as they, of necessity, became a more specialist item, they also became more specialized, with committed vinyl listeners prepared to countenance ever higher prices in pursuit of ever greater improvements in performance. But, as is so often the case, this specialization took two routes, routes with apparently conflicting goals. On the one hand, manufacturers sought to offer increasing flexibility and user configurable parameters. On the other, the ever increasing transparency and resolution of the latest phono-stages was ruthless in revealing the subtlest of changes in circuitry or componentry, driving a move towards ever simpler and more straight-line designs, an approach which had become pretty much de rigeur by the end of the 20th Century.
But the times they are a changing, and so is the audience for vinyl – or at least the vinyl they’re listening to. Ever increasing interest in older stereo and now even mono recordings is presenting new challenges to the designers of today’s phono-stages, while all that increased resolution has opening the window on turntable and cartridge performance, throwing the whole question of cartridge loading into stark relief. Suddenly, the adjustability of phono-stages and the variety of parameters those adjustments must address has become a hot topic: gain, loading (resistive and capacitive) and equalization are all back on the agenda. So much so that the question has ceased to be whether we should switch or not, but how to switch better? So with that in mind, I’ve assemble this contrasting trio of phono-stages, each with a different take on what you should adjust and just how you might set about it. Let the games begin… But before they do, a quick word on source components. I used two record players for the listening: the Grand Prix Audio Monaco with Triplanar VII tonearm and Lyra Titan i cartridge and the VPI TNT VI with its JMW 12” tonearm and the latest rim-drive setup. The JMW’s interchangeable armtops allowed me to run a variety of cartridges, including the Lyra Skala, the vdH Condor, the Koetsu Urushi Sky Blue and the latest Cartridge Man Music Maker, the latter representing highoutput moving-iron designs. Together these options certainly allowed me to ring the changes and investigate the effects and benefits (or otherwise) of loading on different cartridges.
The TEAD Groove Plus SRX
The extended family tree that culminates in the various TEAD Groove models has its roots firmly planted in the original Michell Iso. Designed by Evans for the late John Michell, the Iso might not have been the first standalone MC to line-level phono-stage (lagging behind the Vendetta Research in the US and the FM Acoustics in Europe) but as far as the UK was concerned it was the one that established the breed. Built around Evans’ novel IC-based phase corrective circuitry, it offered a performance whose resolution and transparency (if not its harmonic development and sense of instrumental substance) challenged the then state of the art, in a compact and affordable package that rewrote the rules of record replay almost overnight.
The design has developed and grown from that beginning, improving the performance in areas of weakness, further evolving the technology that has always delivered its significant strengths – as well as adding a new twist in the shape of the ultra-quiet Lithos regulation circuitry. But one thing has remained constant throughout; the Evans phono-stages have always been relentlessly minimalist – until now. Whereas previous models have been factory set for gain and loading, the latest iteration finally makes available the option of user adjustable resistive and capacitive loading. But whilst that’s the most obvious difference compared to the standard Groove Plus, the SRX version delivers a more fundamental step change in performance. The X in the nomenclature refers to the parallel circuit board, e-X-ternal to the signal path, that incorporates the banks of dip-switches for nine different resistive and five different capacitive loads. The SR stands for “Super Resolution” and indicates possibly the biggest change to the overall circuit topology since day one, the development of new front-end circuitry that drops noise and distortion by over 50%. And let’s not forget that the standard Groove Plus was already pretty exemplary in that regard. But what’s more, by making these gains right at the start of the amplification chain, you get the benefits at each and every stage thereafter. As we shall see, the resulting increase in sound quality is far from subtle, easily maintaining the Groove’s place at hi-fi’s top table.