CONVERGENT AUDIO TECHNOLOGY SL1 REFERENCE PREAMPLIFIER and POWER SUPPLY

Description: Known amongst audiophiles simply as "The CAT," the legendary SL-1 from Convergent Audio Technology is one of the most renowned tube preamps on the market, and certainly one of the best you can buy. Debatable? Sure, but the only valid arguments you'll hear will border on esoteric. This particular example includes the optional phono stage upgrade, and your vinyl will sound better than ever. Highs are sparkling and airy, lows are tight and defined, and transient signals are lightning fast. This is the preamp for a seasoned audiophile, one who knows his signal is only as good as his least capable piece. THE HISTORY OF CONVERGENT AUDIO TECHNOLOGYThe Convergent Audio Technology (CAT) story is actually the story of one man — Ken Stevens, an electrical engineer/applied mathematician with two degrees from the University of Rochester. While the school did not have an audio program per se, electrical engineering offered Stevens the best alternative. While a student, he worked on various amplifier and preamplifier designs, all of which were, predictably, solid-state, using transistors and op-amp chips. His first real design was something simply he called the "FET preamp."After graduation, Ken worked for more than a decade as an engineer with first Stromberg-Carlson, then Taylor Instruments, while continuing to refine the FET preamp. He eventually met a colleague who accepted an invitation to audition the FET. The friend's system consisted of an Audio Research SP-3 and D-76 with a Linn Sondek/SME/Denon front end driving Quads. They listened and finally substituted the FET for the SP-3 (or SP-3A). Rather than bowling over his friend, it was Stevens who was, in his own words, "simply thunderstruck." The FET, with its pedigree of measured purity, came in a poor sonic second.Stevens accepted the differences he heard, but rather than abandon everything he'd worked so hard on for so long, he tried to further improve the FET by making it perform even better in every measurable way. The sonic results, as you might have guessed, were the same. The oft-praised ARC preamp was simply better. Reluctantly, Stevens began studying and working with tubes, starting with the venerable 12AX7. Although tubes had been covered in his academic program as items of historical interest, he discovered that they actually had some wonderful characteristics (eg, impressive linearity) that weren't fully appreciated.Having decided to learn still more about tubes, Stevens purchased and built a Dynaco PAS-3X. While the FET was clearly superior at the frequency extremes, the 3X was superior in many other regards. He tried various modifications of the PAS circuit which led to improvements at both frequency extremes. No matter what he tried with the FET, the PAS remained superior in the other areas.Next came a series of experiments with cathode followers. That led to further investigations of other types of tubes, and additional circuit designs. Contrary to popular belief, the CAT's predecessor was a 12-tube monster preamp which was never sold. Frustrations with this design and a long gestation period ultimately yielded the refined 10-tube circuit that remains at the heart of every SL-1 series preamp.Once the design of the original SL-1 was finalized, Stevens began selling it directly to consumers. The primary competition, then as now, came from Audio Research and Conrad-Johnson. Nonetheless, many audiophiles came to know the CAT preamp. A review by Tom Miiller appeared in The Abso!ute Sound; another review by Anthony H. Cordesman appeared in Stereophile. Armed with these first positive reviews, Stevens began to build a dealer network. Like most small audio companies, the one-man CAT operation had its share of teething problems: uneven distribution, suspect reliability, and a constantly evolving product. Filling orders often seemed to take forever, repairs took longer, updates were offered only sporadically, and no two SL-1s sounded exactly alike. During this difficult growing period, CAT had as many detractors as admirers; a much larger segment of the audiophile population wasn't even aware of the company's existence.Near the late 80's, CAT's dealer network began to stabilize, repairs became more standardized, and product delivery began to become more predictable. At about this time, the SL-1 also made a big leap forward in performance. Audiophiles noticed, and the underground press began buzzing about the CAT after a very favorable review by Michael Gindi. Oddly, the model designation remained the same, which caused confusion—two samples of the SL-1 were often two very different preamps. The Mk.II, or final version of the SL-1 Reference, was very reliable, easy on tubes, and sonically splendid.Equally important are the changes that have occurred behind the scenes. A separate production arrangement now has the capacity to supply preamps in quantity. This had never been true of CAT products in the past, when Stevens himself built each one. The new production arrangement has had an added benefit of improved build quality, although rumors of reliability problems continue to plague the preamp.In early 1992, the Reference Mk.II was replaced by the Signature. One of the many things Stevens heard that had improved the performance of his design was George Tice's Power Block. Based on what the Power Block did for the preamp, the SL-1's own power supply was radically redesigned, and now includes an isolation transformer. As a result, CAT now suggests not using any external power-line conditioning with the preamp.A second insight came from the internal suspension of Andy Payor's Rockport turntable, which led directly to the bright blue, viscoelastic, hockey-puck-like feet found on all Signature preamps. These well-damped feet are said to have a very low 13Hz resonant frequency and act to decouple the preamp from vibrations coming up through the cabinet from the floor.The most significant change that led to the Signature was a major breakthrough in chassis construction. The primary design criterion had been the minimization of vibrations and resonance in the chassis. Most owners of earlier CATs had tried all sorts of things to control resonances. Owners had used AudioQuest tube dampers, VPI bricks, and Goldmund cones, all with the CAT sitting on a marble slab on my heavily braced wooden rack. Stevens was fully aware of these tweaks and their sonic benefits. To minimize resonances, the Signature chassis uses constrained mode damping much like the turntable platter introduced a number of years ago by SOTA. Chassis panels are constructed of layers of various materials of different physical properties, a form of construction often found in loudspeaker cabinets. These dramatically heavier panels act to damp the impacts of airborne vibration.FACTORY SPECSFrequency Response .0.1Hz to 600kHz, +0,-3dB (line), 20Hz to 20kHz, +/-0.2dB (phono)Total Harmonic Distortion Less than 0.001% (phono), 0.0005% (line)Tube complment 6x 6922s, 4x 12AX7sInputs Two line-level, one phono, tapeOutputs Two main plus tapeVoltage Gain 26dB (line), 46dB (phono). Both at 1kHzIHF Sensitivity .0.12mVSlew Rate 10V/microsecond (phono), 15V/microsecond (line), risetime of 0.6 microsecondNoise 90dBA below 1V (line), 96dBA below 10mV input (phono)Input Overload 100V (line) and 250mV phonoInput Impedance 50k (line), variable on phono, with 47k and 180pF standardDimensions 19"W x 5.24"H x 12.2"D (preamplifier); 12.2"W x 4"H x 6"D (power supply)Weight 64 lbs.Why Buy from Audio Gold?Audio Gold opened in Crouch End, North London in the early 1990s and we’ve been operating a busy, independent, hifi shop since then. Recommended by musicians, producers, DJs and many of London's record shops as the place to find the right stereo and turntable, we specialise in analogue vinyl systems and combining them with modern digital sources (be they high res or Spotify etc), exploiting wifi streamers and so on as appropriate - our aim is to have a wider range of good quality new and fully guaranteed used decks and stereo equipment than anywhere else in the countryWhat we like most is to help build the right system for you, based on your requirements in terms of sound, space and budget. With unparalleled stock of guaranteed, classic and vintage amps, speakers and turntables alongside new kit, we're also better placed than anywhere else to help you put together a hifi with the right look to sit happily in your home - a stereo that you can love, and use every day. We’re open 7 days a week for you to collect eBay purchases, to inspect, browse, and to listen before you buy. Alongside the Aladdin's Cave of the best of hifi from the last 50 odd years, our record shop stocks 1000s of new and secondhand vinyl LPsIf you have any queries, you can contact us via eBay, email, or by phone on 020 8341 9007. Or make an appointment to pop in to the shop at 308-310 Park Rd, N8 8LAWe use our eBay store to make lovely surplus stock available to a wider audience and to re-home items where the economies of time, money and space don't quite add up for us; we preach 'Extended Life Audio' and hate throwing things away, but London retail space comes at a premium and our engineers have only so much time!Please check out our other eBay listings for lots more new, used and vintage audio equipment and associated ephemera!

Price: 3495 GBP

Location: London, London

End Time: 2024-09-03T11:01:41.000Z

Shipping Cost: 252.38 GBP