Convergent Audio Technology

SL1 Ultimate Preamp MKII

The SL1 series of preamplifiers has dominated the high end preamplifier scene since 1985. Each preamlifier in the series has established the reference standard for its day. The reference against which all others must be judged.

Now we are pround to realease the ultimate version of the legendgary preamp. The new SL1 Ultimate is as pure and grainless as high end preamps costing several times its price. Indeed in direct comparision it is even more pure, more liquid and more natural. Additional this latest SL1 significantly bests the worlds previous reference for transparency and dynamics, the SL1 Signature!

There is no longer need for the music lover to have to decide between a "musical" preamp or an "accurate" preamp. CAT has proven that, when taken to the highest level, these attributes converge, just as they do at a live concert.

LISTEN! - the difference is obvious.

CAT's philosophy is to design our products of relentless refinement to the original SL1 intrduced in 1985. We have identified and eliminated every electronic artifact. Rather than attempting to "synergise" with badly flawed systems, this preamplifier is designed to allow superior systems to reach their fullist potential. The SL1 Ultimate also makes the perfect first step towards assembling such a system. Available with or without a Phono Stage.

Power Supply

  • External Power Supply Chassis conatins the transformer's magnetic field eliminating it as a source of hum.
  • Rectification, Intiail Regulation, and Noise Filtering are all performed in the EPS thereby delivering Pure Quite DC Power into the main chassis eliminating the grain and dryness associated with noise intermodulation.
  • Three Independent Fully Regulated Filament Supplies eliminate the dynamic comression caused by filament to filament crosstalk. These supplies are also noise filtered.
  • Slow Filament Power-Up extends tube life greatly.
  • Quadruple Casacaded Audio Power Supply combines twenty two zero-feedback regulators with over thirty energy storage and bypass capacitors for unequaled dynamic life, soundstage precision and musicality.
  • Isolation Transformer eliminates entry of Radio Frequency noise through the AC power line yielding greater benefits than any of their sonic shortcomings.

Circutry

  • Pure Vacuum Tube Circutry for vibrant and natural music.
  • Extraordinary Quite High Gain Phono Amp (Optional) accommodates both high and low output cartridges.
  • Fast Tube Preamplifier, without any if the high frequency circut-induced edginess which slower preamps frequently substitute for real speed. This speed is maintained even into long runs of cables.
  • Lowest Open Loop Distortion of any preamp yields unforced detail and resolution which must be heard to be believed.
  • Low Feedback Ratios eliminate the aggressiveness of high feedback designs and yet still maintains correct focus.
  • Matched Output Impedance snubs reflection on interconnects quickly, yielding exquisitely lucid midrange and treble.

Chassis

  • Very Strong Steel Chassis with anti-RFI plating ensures hum and RF free operating environment for the circuts.
  • Damping Materials lines both chassis to stop mechanical resonances which would otherwise modulate the electric fields in the preamp.
  • Mechanical Isolation from floor vibrations provided by high loss viscoelastic feet.

Quality

  • Exotic Low Loss Circut Board Material combines the transparency of hard wiring with the low resonant signature and musicality of a circut board.
  • Balance and Volume Controls are military grade rotary switches and solid silver contacts wired with precision resistors.
  • CAT Manufactored RIAA Capacitors use a unique dielectric with several times lower loss than any other dielectric including TFE Teflon.
  • The Best Sounding Precision Resistors are used everywhere for the best resolution and minimum unit to unit variability.
  • CAT Coupling Capacitors are made to our specifications and are better then any other audiophile grade capacitor.
  • CAT Audio Wires uses ultra pure, soft annealled copper and super low loss insulation.
  • Rhodium / Gold jacks for superior connection.
  • Silver Solder used for best electrical connection.
  • Custom Designed Hermetically Sealed Switches.

Convenience

  • Front Panel Muting Switch.
  • Automatic Mute at turn on and turn off.
  • Record / Normal Front Panel Switch eliminated the non-linear load of the turned off tape deck when in normal and provides uncompromised recording quality when in Record.
  • Extra Set of Main Output jacks special audiophile setups.
  • LOAD jack allows changing of the MC cartridge while listening to music.
  • CD and A/V Volume control Tapers available.

 

Specifications (PHONO STAGE IS OPTIONAL)

Gain (@1kHz): Line 26dB, Phono 47dB, IHF phono sensitivity: 0.12 mv

Gain Tracking: Line .05 dB, Phono .05 dB

Frequency Response: Line 0.1Hz to 600kHz +0,-3dB (rise time 0.6 usec) Phono RIAA 20Hz to 20kHz +/- 0.1dB

Harmonic Distortion (@1 volt): Line < .0005%, Phono <.001%

Slew Rate: Line 15 volts/usec, Phono 10 volts/usec

Maximum Outout (@1kHz): Line 50 volts rms, Phono 50 volts rms

Input Overload: Line 100 volts rms, Phono 250 mv rms @ 1kHz

Noise: Line 112dBA below 2 volts output, Phono 96 dBA below 10mv input

Speration: Line greater then 90 dB, Phono greater then 90 dB

Input Impedance: Line 50 kohms, 20pf, Phono 47.5 kohms, 180 pf (user adjustable)

Output Impedance: 100 ohms

Maximum Load: Line under 4000pf , over 5000 ohms Phono under 4000pf, over 10,000 ohms

Dimensions: Main Chassis - 19.0" x 5.24" x 12.2" Power Supply - 12.2" x 4.0" x 6.0"

Weight: Net 64 Lbs., Ship 70 lbs.

Power Requirements: 120v, 60Hz, 80 watts (export version available)