CAT JL 7 Mono Block Power Amplifiers

Overview

Philosophy is the most important aspect of any design. 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 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 JL7 was designed to bring the famous CAT quality into a smaller more convenient chassis and make tube biasing much easier. The JL7 even uses the same driver tube technology as T H E S T A T E M E N T amplifier. This driver is specifically optimised for the high current KT150 tube, but also yields superior results with the venerable 6550/KT88 tube. The new JL7, delivers the famous CAT “drive anything” sound in full measure!

With triode purity, transparency, and vibrancy that surpasses even the most refined low power single ended triode amplifiers combined with brute force current delivery exceeding all other tube amps, even those rated at four times the power, the JL7 is an amplifier which will force you to reevaluate your reference standards.

Power Supply
The power transformer is encased in a separate nickel plated steel housing to contain the magnetic field.

The isolation transformer eliminates entry of AC power line noise into the amp, yielding greater benefits than add-on conditioners without any of their sonic drawbacks or expense.

Slow Filament Power-Up extends tube life greatly.

The Quadruple Cascaded Audio Power Supply uses time compensated zero feedback mosfets and vacuum tubes to deliver unequaled dynamic contrast, resolution and sound stage realism.

Circuitry

Pure Triode audio circuitry produces tonally natural music by eliminating the partition noise inherent in pentode designs and the resulting noise inter-modulation (”grain”).

Low feedback (about 7dB) properly compensated design eliminates the tonal hardness of high feedback and/ or improperly compensated designs while yielding more consistent sound quality.

Ultra-wide open loop in-circuit bandwidth of the output transformer enables operation of the amp’s closed loop response entirely within the open loop response, eliminating any requirement to use high feedback to force the output stage to perform beyond its natural capability.

Massive 15lb. output transformers allows the magnets to operate at maximum linearity while still maintaining extremely low bass capability.

Unprecedented stability into capacitive loads. Fantastic for driving even the most difficult electrostatic speakers.

Black Path Edition Features

Amorphous alloy core has 1/12 the hysterisis of conventional grain orientated silicon steel used by the competition, yielding a level of transparency no other tube manufacturer can match.

Low loss aerospace circuit board material. Legendary Black Gate capacitors.

Chassis

Beautiful Golden Ratio proportions.
Mirror polished stainless steel maintains luster and brilliance with minimal care.

The heavy steel chassis for tremendous strength and the elimination of low frequency vibration, yielding incredible bass solidity and rock solid imaging.

Constrained dampening layer on top plate silences vibration before it can be converted to electro-mechanical noise.

The output transformers are enclosed within their own magnetically isolated housing which is lined with Birch plywood (one of the most musical woods) and potted in place with a combination of epoxy and elastomers for mechanical stability and control.

Mechanical isolation from floor vibration provided by high loss visco-elastic feet.

Convenience
No user bias adjustments. Just plug in CAT supplied tubes and play.

Optibias (TM) compensates for power line fluctuations up to 10% either way. Tubes always sound their best!

Tube life indicator. Green indicates the tubes are still good. Red indicates time to replace.

Tubes operated at only 1/ 4 rated power for very long life expectancy.

 

Specifications

Power:  220 Watts, 4 or 8 ohms, 1%THD

THD @ 1 Watt: 0.005%

Energy Storage: 1800 joules per channel

Bandwidth: 20 Hz to 20 kHz (+/- 0.1dB)

Damping Factor: 14 across entire audio  band

Gain:  27dB (8 ohms), 24dB (4 ohms)

Input Impedance: 100K ohms single ended, 200K ohms balanced

Sensitivity: 2 VAC for full power
Noise: 120 dB below full power
Power Bandwidth: 20 Hz to 30 kHz

Tube Compliment:  2 x 6922 driver and power supply 8 x KT150, triode mode

Dimensions: 20” x 12.4” x 7.8” (L:W:H)  50cm x 31cm x 20cm.
Weight: 88 lbs. (40kg) each unit

Manufacturers Links

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