Audio Research Reference 5 Linestage Preamplifier

Solid-state preamplifiers
Audio Research Reference 5
 Audio Research Reference 5 Linestage Preamplifier

Since the early 1970s, the arrival of a new preamplifier from Audio Research has been an occasion for excitement, and sometime early next week I’ll be getting ARC’s latest thinking on a piece of equipment that, almost literally, sets the tone for the rest of a stereo system.

The fully balanced, zero-feedback, Class A triode Audio Research Reference 5 linestage preamplifier—ARC skipped from Ref 3 to Ref 5 because in the Far East, which is an important market for all high-end audio companies, the number 4 is considered to be bad luck—is a completely new design. Owners of Reference 3s are out of luck; there is no upgrade path.

The Ref 5 departs from previous design practice in many ways. For instance, it is the first Reference Series linestage with circuit boards that are laid out horizontally rather than vertically, presumably to shorten signal paths and reduce noise. In addition, power transformers have been moved off the circuit boards and mounted on the sides of the chassis, presumably to better isolate them (and the rest of the circuit) from noise and vibration. Bandwidth, resolution, dynamic range and scale, the level of noise and grain are all said to have been greatly improved, which, given the high quality of the Ref 3, is saying a good deal.

I will, of course, report on this blog (and later on a separate thread) on the sound quality of the Reference 5, though I think I can make an educated guess about how it’s going to perform based on my experience with the Reference 2 phonostage preamplifier (which also incorporates some of the same design changes as the Ref 5, including horizontal layout of its circuit boards).

Here’s the thing. Since its inception, the Audio Research Corporation has had a single goal: to achieve the lifelike bandwidth, resolution, low noise, and transient response of solid-state without giving up the lifelike air, light, bloom, color, texture, imaging, and soundstaging of tubes. With a couple of exceptions, each generation of gear has taken ARC closer to this goal. Sometimes, the progress made has been subtle; sometimes it has been dramatic. Lately, it has been dramatic.  If the Reference 2 phonostage is a bellwether, then I expect the Reference 5 linestage to have truly solid-state-like transient response (and not just in the midband but in the bass and treble), truly solid-state-like extension at the frequency extremes (with power and definition at the bottom and on the top that are unparalleled in an ARC tube circuit), markedly improved resolution of inner detail, markedly lower tube noise and grain, perhaps a darker, smoother overall tonal balance (with slightly less of ARC’s signature—and to me, quite appealingly lifelike—overall brightness and lightness and bloom in the upper mids), better dynamic range and scaling on the forte side (with less of the a tube circuit’s gemütlich softening of peaks during big crescendos with big ensembles), and even better imaging and soundstaging with improved focus, separation, and articulation.

We will see, of course. But these are among the things that have been dramatically improved in the Reference 2, and I kinda doubt that ARC would let its linestage lag behind its phonostage.

Stay tuned. I will report on whether the Ref 5 lives up to expectations as soon as I've broken it in and begun to listen.