Convergent Audio Technology SL1

It was originally my plan to
source a very special amplifier
to enjoy and hopefully sell. I did
not plan to get a Preamplifier,
because the built in Pre section
on the Audio Aero Capitole and
Prestige are so exceptional, as is
the Consonance R1.3 if other CD
players are used that I felt I didn't
need one, but the performance of
the SL1 is so special, that I just had
to get it.

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The SL1 series has dominated the high end preamplifier scene since 1985. Each Preamplifier in the
series has established the reference standard of its day. The reference against which all others must be
judged.   
Now CAT are proud to release the new generation of this legendary preamp. The SL1 Ultimate, which
we are getting, is as pure and grainless of preamplifiers costing several times its price. Indeed in direct
comparisons it is even more pure, more liquid and more natural. Additionally the latest SL1 significantly
bests the worlds previous reference for transparency and dynamics, the SL1 Signature!
There is no longer a need for the music lover to decide between a "musical" preamp and an "accurate"
preamp. CAT has proven that, when taken to the highest level, these attributes converge, just as they
do at a live concert.

CAT's philosophy is to design their products to neither add to, nor detract from the music. They never
attempt to cover up a design problem with another problem, nor do they try to introduce a supposedly
complementary problem to "Synergise" with it. Two wrongs do not make a right. Only the eradication
of the problem is correct.
The SL1 Ultimate is the product of relentless refinement to the original SL1 introduced in 1985. We
have identified and eliminated every electronic artefact. Rather than attempting to "synergise" with badly
flawed systems, this preamplifier is designed to allow superior systems to reach their fullest potential.
The SL1 Ultimate also makes the perfect 1st step towards assembling such a system.
Available either with or without Phono Stage.

Power Supply

*External Power Supply Chassis contains the transformers magnetic field eliminating it as a source of hum.
*Rectification, Initial Regulation and noise filtering are all performed in the EPS thereby delivering pure,
quiet DC power into the main chassis eliminating the grain and dryness associated with noise intermodulation.
*Three independent fully regulated Filament Supplies eliminate the dynamic compression caised by filament
to filament crosstalk. These supplies are also noise filtered.
*Slow filament Power-Up extends tube life greatly.
*Quadruple Cascaded Audio comprising twenty two zero feedback regulators with over 30 energy storage
and by-pass capacitors for unequalled dynamic life, soundstage precision and musicality.
*Isolation transformer eliminated the entry of Radio Frequency noise through the AC Power line yielding
greater benefits than any of the expensive add-on power line conditioners without any of their sonic shortcomings.

Circuitry

*Pure Vacuum Tube Circuitry for vibrant and natural music.
*Extraordinary quiet high gain phono amp (Optional) accommodates both high and low output cartridges..
*Fastest tube Preamplifier, without any of the high frequency circuit-induced edginess which slower frequently
substitute for real speed. This speed is maintained, even into long runs of cable.
*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 maintains correct focus.
*Matched output impedance snubs reflections 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 circuits.
*Damping material lines both chassis to stop mechanical resonances which could otherwise modulate the electric
fields in the preamp.
*Mechanical isolation from floor vibrations provided by high loss viscelastic feet.

Quality

*Exotic low loss circuit board material combines the transparency of hard wiring with the low resonant signature
and musicality of a circuit board.
*Balance and volume controls are military grade rotary switches with solid silver contacts wired with precision
resistors.
*CAT manufactured 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 their specifications and are better than any other audiophile grade capacitor.
*CAT Audio Wire uses ultra pure, soft annealed copper and super low loss insulation.
*Rhodium/Gold jacks for superior connection.
*Silver solder used for the 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 eliminates 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 fior special audiophile setups.
*LOAD Jack allows changing MC cartridge loading whilst listening to music.
*CD and A/V Volume Control Tapers available.

Specifications: (Phono Stage is optional)
Gain (@ 1kHz)	Line 25.5 dB Phono 47 dB
Gain Tracking	Line .05 dB, Phono .05dB
Frequency Response	Line 0.1Hz to 600kHz +0, -3dB
Harmonic Distortion           (@ 1 volt)	Line < .0005%    Phono < .001%
Maximum Output (@ 1kHz)	Line 50 volts rms    Phono 50 volts rms
Input Overload  (@ 1kHz)	Line 100 volts rms     Phono 250 mv rms
Noise	Line 112 dBA below 2 volt output Phono 96 dBA below 10 mv input
Separation	Line greater than 90dB Phono greater than 90dB
Input Impedance	Line 50 kohms, 20pf Phono 47.5 kohms, 180pf (User adjustable)
Output impedance	100 ohms
Maximum Load	Line: under 4000pf, over 5000 ohms Phono: under 4000pf, over 10,000 ohms
Dimensions	Main Chassis - 48.3 x 13.3 x 31 cm Power Supply - 31 x 10.2 x 15.24 cm
Weight	Net - 29kg, Ship - 31.75 kg
Power Requirements	240V, 50 Hz 80 watts, for Australia.