Pre/Power Amplifiers

If life is a journey, rather than a destination, then some brands, Audio Research included, have rather more air miles under their corporate belts than others. From a boutique audiophile business to a period swept up in the fast lane of venture capital, Audio Research has now returned to its roots. It's a gloriously niche brand that understands 'what it does' and is now, once again, driven and engineered by a team that is passionate about serving the diehards of the audiophile community.

What Audio Research 'does', in the main, is make very fine tube amplifiers, and while the brand was busily circumnavigating the globe, its amplifiers have been on a journey – an evolution – of their own. So while the REF80S featured here may well be a new and, viewed via the colourful prism of high-end hi-fi, 'affordable' step into the realm of ARC's Reference series, it's not some fresh experiment on us audiophile guinea pigs. This is fine wine, not home brew...

It's In The DNA
In practice, the genetics of this latest 70W-rated stereo power amp can be traced back through a few generations of Audio Research thinking. The industrial design, dominated by those etched-onto-acrylic 'GhostMeters' is a masterwork in its own right, while the frontal aesthetic and footprint of the REF80S is clearly modelled on the bigger REF160M and REF160S [HFN Aug '18 & Feb '20]. These big beasts of the tube amp jungle also feature 6H30 double-triodes as phase-splitters/drivers and bulbous KT150 output tubes, albeit twice as many as we find in the REF80S. They also offer switchable Ultralinear (UL) and Triode tube configurations, a popular novelty carried over into the REF80S.

Other production engineering updates are enjoyed by the REF80S, including the four-layer PCBs debuted in the REF160M/S. However, I'm tempted to suggest that many of the core circuit features that actually inform the sound of the REF80S owe more to the earlier 6H30/KT120-equipped VT80 [HFN Oct '17]. This was not only the first ARC amp to utilise an auto-bias regime but its custom-built output transformer is the blueprint for the lump of iron and copper weighing down the rear of the REF80S.

Incidentally, ARC's transformers have been made in North America for some 40 years – a third-party relationship that gives it decisive control over the sound and consistency of its tube amplifiers. Another tradition, despite the modern quad-layer boards, is ARC's avoidance of any flow soldering in its Minnesota production facility. Everything is hand-assembled, hand-wired and hand-soldered. Since the buyout, an increasing amount of assembly has been brought back in-house, or kept very local, including the laser-etching of the meters and chassis painting. Even some staff who had left in recent years have returned – important in ARC's ambition to offer service for every tube product it has ever made.

Step On The Ladder
The REF80S also marks a renewed emphasis on providing more accessible avenues into the ARC product family. We reported recently [HFN Feb '21] on Audio Research's new, and even more affordable, 50th Anniversary I-series that'll kick off with the I-50 integrated and be joined by the P-50 pre and A-50 power amp by the end of 2021. This marks a return to the, in my view, sensible strategy that gave us the SP17 preamp, VS60 power amp and VSi60 integrated some 7-8 years ago.

But back to now, and the REF80S's ghost in the machine. I've commented before on the accuracy, or otherwise, of ARC's metering. The old-school meters fitted to the REF75 [HFN Nov '12] were reliable, the large-format meters on the GS150 [HFN Jan '15] and the embryonic 'GhostMeter', unveiled on the REF160M, proving of decorative value only. Perhaps ARC's technicians read my Lab Reports because the subsequent REF160S's meters were better calibrated, as are the ethereal apparitions that grace the REF80S's visage.