CAT JL-2 amp upgrade

I would hope that a JL-2 or JL-3 owner who had the upgrade done would chime in with some before and after comments. I have seriously thought of this with the JL-3 Sig's but they sound so mighty good already. But if the upgrade brings on more resolution and dynamics, woo hoo, that would be awesome. Just wish I could hear the two versions side by side. Would be a lot easier to quantify the differences to determine the value added right then vs. putting that same money elsewhere in the system. But CAT products do not see a version change too often so this change could truly be incredible.

In Late 2004 I had my early model JL2 updated to the Mk II status. The biggest improvement I heard was a great reduction of noise and a much more quieter backgroud. This very postive change was apparent from the first moment I played the first tune on my table. The reduced noise level results in better transparency and more inner detail being revealed. Was it worth it, Yes in my opinion.

Note: This is not the $5000 signature upgrade which is much more extensive and costly but the Mk II upgrade from there early version of the Mk I which I believe was about $1000 at the time. A nice improvement indeed.

Johnny

Hi, Johnny.
Do you remember how long it took CAT to return the amp? Do you know what they did internally to the amp for the standard upgrade, or do for the Signature? Did the changes to the amp reveal any changes necessary for the rest of your system, particularly cables or power cords? How many hours did you put on your original tubes before retubing? Do you get a warranty with the upgrade? Thanks for any further information.
Steve

I just purchased the CAT JL2 and am also trying to determine from people who have had the upgrade to Sig to describe the improvements and quantify the improvements (obvious improvement, subtle improvement, etc.). The person I purchased the amp from (a dealer) said that he has the new Sig but doesn't hear much improvement so far.
The Sig isn't really broken in yet but he will let me know when it is. My thoughts on the JL2 versus the Manley 350 monos I was using are as follows. The Manleys have a much fuller (sweeter, richer) sound across the spectrum (I prefer this), the JL2 sounds lean in comparison. Where the JL2 betters the Manley is in detail, transparency and coherence at high SPL's especially with large ensemble bands. I think where the JL2 gets this tendency toward detail and accuracy is from the output tubes (6550's). VTL used to use these in their old 300 monos and when they switched to KT90's the sound became decidedly more musical.
I did almost immediately get rid of the sovtek 6922 input tubes in favor of Amperex SQ 6922 made in Holland (nice improvement). I also replaced the stock EI 12ax7's with Amperex 12ax7 D getter long plates also a nice improvement.
I have some Amperex 12au7's d getter long plates in transit. For my taste the Manley was a better match in terms of musicality but the CAT does everything else better. So I guess I will start down the path you have travelled John. Finding a preamp (to replace the CAT Ult MK2) with full textural qualities to mate with the CAT's somewhat analytical presentation. Johnny, if you got the MK2 upgrade for 1000,
you did well. Ken told me he is charging 3000 for that upgrade and is urging people to do the Sig upgrade for another 2000 which is much more comprehensive

I know what you mean regarding the Manley vs. CAT products. Both operate from totally different design philosophies. For the past year and a half I have owned the Manley steelhead phono stage and it is rich, full bodied, has nice tone and is very enjoyable to listen to. The cat Ultimate preamp is faster and more detailed than my manley but lacks size, substance and body which is my I sold my cat preamp and bought a Jadis JPS 2 (the linstage version of the Jadis JP80). Ken Stevens will insist when you talk to him his design is superior to others but this is true with most manufactures and the reality is all designs are imperfect. When I go to live concerts I hear the excellent detail and great bottom end extension of the Cat. When listening to live music I also hear the rich full body sound of the Manley and Jadis products which add size, substance and rich tonality to the music, something sorely lacking the Cat preamp.

The Cat JL2 amp has the common Ken Stevens design signature that the preamp has and yes it is not as rich or full bodied as other amps but I will accept this one weakness for the many strengths this amplifier has. I prefer the Jadis line stage and Cat JL2 combo where Ken prefers the JL2 and Ultimate mix. Going from the JL2 Mk I to the JL2 MK II was a nice upgrade Ken did for me while my amp was in the shop for some repairs and for 1k the price was well worth it because of the reduction in noise and greater transparency. The Jl2 went from a numeric rating of 9.1 to 9.4, very noticeable and positive but not huge as the basic character is the same. When talking to Ken Stevens about the JL2 Signature $5,000 upgrade he said the improvement would be about the same as going from Mk I to Mk II, what I did in late 2004 with my JL2. The biggest improvement in the JL2 Signature over the standard JL 2 is the addition of black gate caps in the power supply. He told me the other circuit board design changes were very minor sonically and was done mainly to improve reliability. If I had to guess based my past experience the signature upgrade would take this already excellent amplifier to a 9.7 but at 5k the improvement becomes quite costly and there are a lot of other ways to spend 5k including buying more records, upgrading your preamp or upgrading a turntable all of which I suspect will provide more of bang for the buck improvement for the money. Yes black gate caps nice to have if you have the money to spend but not a necessity, the JL2 is already so good in many ways.

There are three things you can do yourself to really improve the performance of the Cat JL2 for very little money, about $200.

1) Remove and replace the cheap tin male IEC connector in the JL2 with a pure copper or bronze furutech IEC. This made a bigger improvement than I expected giving cleaner power to the power supply resulting in greater energy and more drive.

2) Remove and replace the two poor quality Cardas brass female rca’s on the side of the amp with Vampire pure copper rca’s. You will notice cleaner and clearer sound and improved bass that is fuller without the bloatness of brass.

3) Remove and replace the two brass cardas speaker binding posts with copper. Eichman cable pods or a good pure copper posting will yield positive results similar to the rca’s mentioned above.

If you want even more performance from your JL2 bypass the internal 20 amp fuse and fuse holder located next to the IEC and expect another 3-5% improvement in sound. All these just take a little time, very little money and a good soldering iron.

Johnny