REF6 SE: Capturing More of Live Music’s Natural Cues



As attested to by uniformly positive reviews and customer feedback, the latest REF160 series amps (and now the REF750SEL) manifest speed, time coherence, dynamics and transparency –an overall aliveness– never before experienced in Audio Research tube amplification.

This is largely due to the superior capacitors and wire technology breakthroughs made available since the development of our last generation of amplifiers.

The newfound clarity and lack of blurring of these latest amplifiers also revealed an opportunity to improve music’s temporal coherence –timing and phase accuracy- in the preamplification that drives them, by applying the same techniques and ongoing parts refinement.

There are a total of 28 parts and wire upgrades incorporated into the REF6 SE, which has been thoroughly tested and sonically vetted for over six months prior to its release. Each of these substitutions were made specifically for their superior construction geometries, precision and dielectric material properties, working in concert to reduce energy lag and signal smearing along the entire circuit path from input to output.


Experiencing the synergy of the REF6 SE driving a REF160S or REF160M monoblocks, there is an apparent liberation of the vacuum tube’s greater untapped potential—the largest single step forward in realism we have offered since the introduction of our Reference series components 25 years ago. Going forward, it is evident that fine-tuning in the time domain will yield many of the subtlest and most elusive cues of audio realism yet to come. Not coincidentally, the most convincing loudspeakers today benefit substantially from this design emphasis as well.

The pure class-A, zero-feedback, all-triode audio circuit of the REF6 SE is matched by a power supply capable of delivering all of its power-amp-like energy reserves–at all frequencies–as quickly as the dynamic requirements of the music signal dictate. The new wiring and parts are specifically tuned to accelerate the meeting of these instantaneously fluctuating temporal power demands.

What does this mean for the serious music lover? From the lowest bass to the highest harmonics, the entire high-joule power supply reserve of the REF6 SE is now on tap for lockstep bloom of each musical note’s attack, sustain, and decay to unfold in the correct sonic temporal order, without dynamic energy lagging behind the music’s rapidly shifting signal contours at any instant. Bass pitch, impact and reach now fully match the mid-to-upper frequencies’ purity, speed, and extension.

The REF6 SE exhibits an exceptionally unbounded ‘dual-mono’ soundstage envelope, extending spatial hang-time of the subtlest ambient trails and depth to a degree not previously achievable in a single-box Reference preamplifier. Speakers disappear substantially more as the apparent origin of the music, with unparalleled separation, localization and focus in all planes. Enveloping coherence binds all of these musical elements into a more thrilling sense of a seamless event unfolding before you.

The speed and transparency of the REF6 SE unravel the subtlest to most complex musical passages without low-level blurring or rounding. Vocal sibilant purity will be readily apparent and constantly appreciated. A piano becomes more authentically percussive. Properly executed modern vacuum-tube technology is capable of faster pace and timing accuracy than solid-state devices under real dynamic musical conditions.

Finally, live music’s room-energizing directness, the sheer ease and density of intensity, along with the breadth and harmonic complexity of its tonal color palette, are advanced substantially beyond previous ARC product generations.

Entering our 50th year, we continue to reveal even higher performance available in the vacuum-tube. Prepare to be swept away by a REF6 SE at your nearest Audio Research dealer. Experience Bill Johnson’s original ethos, more alive and well than ever at ARC: The music is the trophy, not the electronics.


-Warren Gehl

ARC Engineering Sonic Development Evaluator

Sam Sadowsky
Author: Sam Sadowsky