Audio Research Ref 6SE pre-amplifier review
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Audio Research Corporation (ARC) as we know it today, was founded in 1970 and has been manufacturing valve amplifiers since that time. The roots of the company go back as far as 1951. By1970 there was no other American home audio manufacturer producing valve amplifiers, such was the speed of introduction and faith in transistor technology within the industry. Audio Research Corp. had other ideas, with the firm belief of the apparently superior sound quality valves were capable of. This argument still remains a point of hot debate, but undoubtedly there is a tonal difference between the two types. Spool on five decades and many models past and we have the introduction of the Reference 6SE preamplifier and Reference 750 SEL power amplifier.
Undoubtedly ARC have over the years, produced a wealth products which are respected and revered today as much as ever. As a classic equipment enthusiast, I can attest to just how sought after and cherished some erstwhile models are. And with very good reason, as many compare extremely favourably to modern modern designs. They are about as far off a “throw-away” product as you can have. This review is for the Reference 6SE line preamplifier which is a line input only unit. It's a fully balanced Class A design with zero feedback. Inside the weighty aluminium casing are six 6H30 tubes for the analogue stage and another single 6H30 for the substantial power supply, with a 6550 providing valve regulation.
The unit, as you would expect from ARC, is substantial and well constructed. This is not merely for aesthetic reasons but provides damping for air-borne and other external vibrations - unwanted by any audio device, but especially one equipped with valves. Of course, despite the care taken with construction, the unit should still be supported on a rigid surface or isolation platform. The design has a Deco look with no hard edges visible on the front panel or sides. The two large aluminium rotary controls provide input selection and volume setting, with the level clearly displayed on the front panel. It's a rather casing for a preamplifier, in fact as big as many a power amplifier, but this is no doubt necessary for air circulation as, thankfully, there are no fans inside. The perspex top cover is user removable to access the valves. These are packed separately and have to be installed by the purchaser, but this is a straight forward job and well documented in the manual.
The 6SE preamplifier has a total of 8 inputs – 4 single-ended RCA and 4 XLR balanced. There are 3 outputs: 2 main outputs and 1 record output which is unaffected by the volume control and has 0 dB gain. The main outputs are replicated as balanced (12 dB gain) or single-ended (6 dB gain). The inputs are selectable with the left-hand rotary control and can be named from the set-up menu. Usefully, one of the inputs can be assigned to by-pass the volume control in order that a source with its own level control (e.g an AV processor), can avoid having two such controls in the signal path. All in all, it's very nicely designed and user-friendly with a set-up menu which is intuitive and very straight forward. A remote control is supplied from which the functions can all be accessed.
Ideally, this brand new out-of-the-box pre should have at least 100-200 hours run-in time before serious listening, but can you imagine..... that would be akin to asking a 5 year old not to unwrap his/her newly released Playstation 5 until Boxing Day. Ridiculous! It just wasn't going to happen. Whilst it was ever so tempting to partner this pre with the matching ARC beefy power amp, I wanted to have a reference by keeping the rest of the system unchanged. I used a brutish pair of JL3 valve mono-blocks by Convergent Audio Technology, another respected U.S company, albeit considerably smaller than ARC. Each mono-block has a stack of 6550 valves which allows for a 150watt pure Class A design.
I managed to reach about 50 hours use before I began to listen more seriously. On switch-on, there is a 45 second mute period during which the pre settles down. Incidentally, the 6SE keeps a log of the time the unit has been in use to aid valve wear assessment. The signal valves shouldn't need replacing before at least 1500 hrs use. What struck me immediately was just how smooth sounding this unit was, positively silky in presentation virtually straight out of the box. It was very beguiling with even the most difficult hard-sounding recordings, always coherent and in control. The other immediately striking feature was the strong LF ….very forceful and punchy. It was all very promising.
It's easy to believe that a preamplifier is just a volume control with an input selector knob, so can't have such a big impact as say replacing a power amp, but nothing could be further from the truth. The pre is actually the “heart” of the system if you will, and the power amp the muscle. Both are as important as each other, with the former ensuring a powerful, confident, smooth flowing signal without ripple or over-emphasis. Conversely, on the couple of occasions I've heard a passive pre-amplifier, I have noticed a lack of force and punch, even when its coupled with a hefty power amplifier. Over time, if anything the sound from the Reference 6SE became even smoother, more open and beguiling. I played a vast array of music, bizarrely eclectic, from Monteverdi to Motown. Out came my recordings I consider faultless which are breathtaking in their realism (Tchaikovsky 6th, Ashkenazy, Decca, Rachmaninov Symphonic Dances, Eiji Oue, Reference Recordings)). The sound I heard could be best described as “majestic” and expansive. It was never constrained, restricted or tiring, felt consistently elegant and super-competent. To my ears, it was a characteristic dress-circle location as opposed to the front stalls. It was very different to what I was used to with my own pre, an FET design with valve rectification made by the original Audio Note (Japan) company. I had become accustomed to more of a roller-coaster ride, exciting as your ears get pummelled but dreading what was coming next. The drawback with my pre is, if the recording is less than pretty, then you're gonna be sent flying off the rails! By contrast the 6SE is a Bentley, providing a much more relaxing but still satisfying ride. On occasions, I did feel that the 6SE could be a bit too polite and not as searingly incisive as I have been used to, especially at the extreme upper end of the audio spectrum. However this is entirely my individual taste and there are very many, probably the vast majority, who relish the consistent performance and musical presentation of this design.
Dress-circle or mosh pit, the choice is yours! Without hesitation I would urge you give the 6SE a good listen and consideration. The 6SE provides a very solid and full-blooded performance and deserves its Reference label. It's a satisfying listen and I'm sure the design will be revered by many, not just now but for years to come.