CAT (Convergent Audio Technology) JL5 Black Path
Review organized by Marc Loubeau / Prestige Audio Diffusion
Review sample provided by Vermeer Audio
Retail prices including VAT:
JL5 Black Path Edition – 19.600 Euro (as reviewed)
JL5 Black Path Edition LE – 28.500 Euro
CAT’s mission is to remove the barrier between the listener and the music and the company philosophy is to design products to neither add to nor detract from, the music.
The company maintains a low profile, not only in terms of exposure but also on its website. The site opens with a quote from Buddha: “THREE THINGS CANNOT BE LONG HIDDEN: THE SUN, THE MOON AND THE TRUTH.” Clearly, the people at CAT want us to care about music and not so much about technical details. I can respect that but there’s one thing that I wanted to know but that’s nowhere to be found: where are these products made? Elsewhere on the ‘net, I found the answer: USA!
The JL5 even uses the same driver tube technology as THE STATEMENT amplifier. This driver is specifically optimized for the high current KT120 tube. The new JL5 is said to deliver the “drive anything” sound of its bigger brothers while being fully competitive with the older 6550 version of the more expensive JL2.
CAT also offers the JL5 Black Path Edition LE which is the Limited Edition. This is a brand-new upgraded version with Teflon boards that will be available soon.
With 120 Watts into 4 or 8 Ohms at 1% THD, a bandwidth of 1 Hz to 70 kHz at +0, -3dB and a 116dB noise floor, the JL5 promises stellar technical performance. The manufacturer feels that it is silly to use long internal lengths of cable just for the convenience of having all connectors on the amp’s rear end. Instead, the JL5 has its input and output connections on the sides and right where the internal circuitry needs them. The input connectors sit right next to the input tubes and the speaker cable connectors sit right next to the output transformers. A nice extra benefit of the centrally-placed output transformers is that the amplifier has evenly distributed weight which makes its large heft easier to lift and move around.
JL5 with the Tube-Protector cages removed. This is necessary when using banana connectors.
The amp has 4 x 6922/6DJ8 driver/PS tubes and 8x KT120 power tubes in triode mode. Along with some more measurement specs, this concludes the technical information that is available on the CAT website. Perhaps they want people to listen and not worry about the technology. But for those who are interested in the details, I found lots more useful information on the GCaudio JL5 page, which I have summarized below.
Power Supply and Circuitry
The Power transformer is encased in a separate nickel-plated steel housing to contain the magnetic field.
An isolation transformer eliminates entry of AC power line noise into the amp, yielding greater benefits than add-on conditioners.
Slow filament power-up extends tube life greatly. The quadruple cascaded audio power supply uses a combination of time-compensated zero feedback MOSFETS and vacuum tubes.
Pure Triode audio circuitry eliminates the partition noise inherent in pentode designs and the resulting noise intermodulation (”grain”).
Low feedback (about 7dB) properly compensated design eliminates the tonal hardness of high feedback and/or improperly compensated designs.
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 allow the magnetics to operate at maximum linearity while still maintaining extremely low bass capability.
Unprecedented stability into capacitive loads, thus great for driving even the most difficult electrostatic speakers.
Black Path Edition Features
Low-loss aerospace circuit board material.
Amorphous Alloy core has less than 1/12 the hysteresis of conventional grain-oriented silicon steel used by the competition.
Black Gate power supply capacitors and BLACK PATH audio capacitors.
Heavy steel chassis, Mirror-polished stainless steel, and Golden Ratio proportions.
The output transformers are enclosed within their own magnetically isolated housing which is lined with Birch plywood. A constrained damping layer on the top plate silences vibration before it can be converted to electromechanical noise.
Mechanical isolation from floor vibration provided by anti-resonance viscoelastic feet.
Fully auto-biasing. OptiBias(TM) compensates for power line fluctuations up to 10% either way meaning that the tubes always sound their best.
Tubes are operated at only 1/4 rated power for very long life expectancy.
Tube life indicator. Green indicates the tubes are still good. Red indicates time to replace.
Power amplifiers do not get any simpler to connect than the JL5. There’s nothing on the rear end but the power inlet and a big power switch
You’ve sold the ESL15A’s???
Did you replace them with something else?
Indeed. ATM I am using only the Magico S1 Mk2’s. Long story, which I will work into a new chapter of the HFA Audio History when I find the time.
A typically excellent and thorough review of an American brand that doesn’t seem to get much coverage stateside. One question did something weird happen with your editing? The review seems to start mid-stride without any sort of introduction. Not that it matters it was another great read thanks!
Hi Jon, you’re right. In an effort to improve the readability by shuffling parts around, I agree I actually made it look less great. It started with a lack of Company Background that made me question how to start the article. I’ve now added a tiny bit of info and have done some more shuffling and I think it looks better now:-)
Nice review! It’s all in the match, and CAT matches very well with Ceramic based speakers. Most succesfull here was a pairing with the German made Consensus speaker. Having owned almost all CAT models starting end 90’s with the SL1, the JL1 is still a favorite CAT but they need service and attention. Lions can be lifelong friends, but not with everyone. Watch the Lion Wisperer at Youtube and see what i mean..
Cheers. Ron Callas-Audio