CAT JL-2 amp upgrade

Thanks Johnny for the report here. Your evaluations of the CAT preamps and amps to the competition very much mirrors my reports elsewhere on A'gon. These amps are very special indeed.

Your suggested DIY updates sound interesting but I would be weary of bypassing the fuse. These amps pull a lot of current from the wall and any little problem I would prefer to have protected by a fuse. Perhaps a "safe and sane" compromise would be to replace the fuse with one of the "audiophile grade" fuses? If it fails, it ends up costing you $20 or $30 vs. a major amp disaster .... or your house burning down.

John

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I talked to Ken Stevens before bypassing my fuse and fuse holder and since I already have a 20 amp circuit breaker at my main fuse box we both agreed it should be fine. The 20 amp fuse was designed in for warranty reasons but in the 8+ production years for the cat amps he is aware of no problems with any potential power surges or damage that resulted. Ken indicated in a previous conversation that the JL2 is "self contained" meaning all major parts and assemblies are enclosed in a seperate retangualr steel case. The input transformer, output transformer and all wiring is enclosed with thick gauge steel greatly reducing any risk. In the rare event a fire does occur in one of these steel enclosures, none has occured yet, the damage would be limited to that specific area.

Johnny

Enjoy

Johnny

Johnny, thanks for the info. Has anyone experimented with tube rolling the output tubes in their CAT amps? Ken told me I was asking for trouble and I would end up blowing up the amp. I ordered the SED Svetlana 6550C tubes today from Upscale Audio. Kevin from Upsacle gave me a similar warning as Ken's about fooling with 6550 variants (KT90's, KT88's etc.)in CAT amps. I have got to say as I am listening to the CAT JL2 right now that the improvement from changing the 12AX7's and 6922's has made the amp much more musical and when my Amperex 12AU7's arrrive it should add more musicality to the presentation. I am very happy with the sound right now. My JL2 sounds very quiet, I don't feel the need to do the upgrade to improve performance in that area. My previous plan was to find a preamp to replace the CAT Ultimate MK2 to increase the musicality of the presentation but I am rethinking that option now. I may turn my attention to the digital front end instead.

Bart

I had a JL-2 and decided to sell it and purchase a new JL-2 Mk2 Signature. I am very happy I did as the signature version is a definite improvement over the non-Signature version. I believe that more expensive caps (black caps) are used in the Signature version. What you get is lower noise floor, better imaging and dynamics. The improvement in the sound makes the $5000 upgrade worth while IMHO. I am very happy that I got the Signature version. I have had it for a few months now. Happy listening.

Posbwp555, what preamps have you auditioned to replace your CAT? Have you found something you like better? I have a JL2 and use to have a SL1, which I have replaced with a Placette Active. I'm wondering about other pre-amp matches that might work well.