Audio Research, Sonus faber, and Transparent Cable: that’s basically high-end audio royalty, all rolled into one extremely elegant and competent system. OK, so two of the three brands (Audio Research and Sonus faber) are subsidiaries of the McIntosh Group, but their autonomy and manufacturing smarts make them distinct entities in their own rights, and they have been a trio of brands known to work in harmony long before two of them teamed up!
The other common factor between these three well-established high-end audio brands is a desire to push the envelope. Any of these three companies could rest on some quite heavy laurels and coast for a decade or so. And, let’s be honest here, inertia is endemic in the audio industry and – digital audio notwithstanding – this is not the fastest-moving river in consumer electronics. But, despite – or perhaps ‘because of’ – that, all three brands keep developing new products that often take their brands in very different directions. The old days of the big, mellifluous sound of Audio Research and the warm and enveloping sound of Sonus faber are behind us. They walk a different path today.
However, for this system, we have chosen a mix of the old(ish) and the new. The old is one of the longest serving products in today’s Audio Research line-up, and the only purely solid-state product in its current portfolio: the CD6 CD player. Despite a fine DAC in the company’s Foundation Series (the DAC 9), CD is still a very popular medium with Audio Research owners, and the CD6 refuses to quit!
The CD6 is unashamedly old-school in places. Its one-colour faceplate harks back to classic Audio Research products, its top-loading transport is the superb NOS (new old stock) Philips Pro2 mechanism (Audio Research bought up the last batch) and the green numeric LED panel harks back to classic players of the 1980s and 1990s. If it ain’t broke, don’t fix it!
However, the CD6 is not some throwback from audio’s recent past. Alongside the CD mechanism, there are four digital inputs (two Toslinks, RCA S/PDIF, and an asynchronous USB connection), all of which are said to handle up to 24-bit, 192kHz PCM files. While not at the bleeding edge of TLA (three-letter acronym) technology – DSD and MQA are MIA – the CD6 is ideal for those with an extensive CD collection who have no burning desire to rip it to anything computery but might want to dip a toe into the high-resolution waters. If you find those waters so refreshing, you start looking to DACs in the future, the CD6 keeps your options open by including a BNC-equipped S/PDIF output and an AES/EBU XLR connector. Or you can stay with the on-board quad 24-bit DACs of the CD6 a little longer and use its RCA single-ended or XLR balanced line-level analogue outputs.
Talking of analogue outputs conveniently moves us to the core of the system; the Audio Research LS28 line preamplifier from the company’s Foundation series. In fact, Audio Research has been doing a spot of consolidation recently, and in line preamps, there’s now just a Good-Better-Best line-up (with the LS28, the REF 6, and the two box Reference 10 – with the GSPre and the rest of the GS line allegedly soon to disappear). This preamplifer features four single-ended RCA and four balanced XLR inputs, with two RCAs and two XLR outputs. Audio Research learned a lot from its most recent Reference series preamplifiers, and the technology (both solid-state and valves) has filtered through to the LS28. The audio circuit uses a quartet of 6H30 valves. This valve is fast becoming the popular choice for preamp designers wanting to move from the ubiquitous 6922 because they are reliable, long-lived, readily available, have low plate resistance, high transconductance, and requires no cathode follower. In short, even before you take sonic performance into account, the 6H30 is an obvious choice for a modern high-end valve preamp.