Sonic difference between the CAT JL2 Sig & CAT JL3

Wow, I am envious. The big and beautiful Avalons. Maybe I can bring the amps and aesthetix preamp and you bring the speakers and we can have quite a concert. 8-)

As I recall from following the Avalons over the years, the Ascent and then later the Eidolons needed powerful amps, typically reported ss amps, to really come to their full potential. But with the big Avalons, don't these have the subwoofers with accompanying sub amps? If so, these speakers could be much easier to drive than their smaller sibblings. None of the Avalons have any nasty dips in their impedance curves which makes it equally nice. This opens the door for consideration for either the JL-3s or a pair of JL-2s.

I have wanted to hear a head-to-head of the two CAT amps but logistics have just not allowed it .... yet. Maybe I will get the chance this year. But in this case, it would be the JL-3 sig vs JL-2 std models which both have the same capacitor types. Here it would come down to the potential of greater dynamic contrasts, ease, perhaps low-end control, etc., rather than much if at all any tonality or resolution differences.

The JL-2 Sig has the latest cap changes as does the JL-3 Sig MK II. These model suffixes get to be a little complicated! I have held off with the MK II update only because of the concern of shipping the amps back to CAT. This is almost something I would deliver myself to avoid the potential of damage. And for now, what the JL-3 sigs do for me leaves me little wanting for more tweaking to them other than getting the updated circuitry to better handle tube failures. And a CAT dealer can do this with some parts changes. I understand this latter work is standard to all CAT amps delivered now.

In my smallish room, 13x18x7.5, the single JL-2 would be plenty to bring happiness with the SoundLab A1s. But I bought the JL-3s with the intent of them being my last amp. I have bigger and greater plans for a larger room in the future. And I have felt that it would most likely only be Avalons that would displace the SoundLabs from my system. So I bought the JL-3 with all this in mind rather than to my specific needs at the moment.

With the money you are looking to spend, and having premier speakers in this wonderfully sized room, you need to find a way to hear these amps for yourself. A single JL-2 might be a good start if cost is an issue. But ideally, you will want one amp per speaker to truly get the separation and subtle details that I have no doubt your speakers are capable of. And then it comes down to a pair of JL-3s driven full range or a pair of JL-2's biamped. There's just no way to know how the outcome would be unless you tried it right then and there. I would love to have the opportunity to hear this. Either way, it's the same number of tubes so plan on listening to your music in summer clothes. 8-)

John

Wow, roaming around on the Avalon site makes me feel like a kid in a candy store. These things are works of art.

Bart, there might be some value to further research the VTL 750 amps. Albert Porter has had these for a year or so, and after much tube experimentation, he is very excited with their performance. He uses two pairs in his system. And he is a heck of a nice guy here so he shuold be able to give you some insights as to pros/cons of these amps. I have pestered him to try a pair of JL-2s in his system just to get an idea of the CAT vs. VTL sound but getting a pair of CATs is not an easy task and again, he really likes the VTLs.

And concerning the Callisto, I love this thing. But it took me a year, and for the Io as well, to go through a lot of tube trials to really get this thing to perform like nobody's business. And a quick look under the hood by Steve Huntley of GNSC here in MN shows there is much to be improved in these units with significant parts updates, wiring changes, etc., that far exceeds their "Signature" updates. But before you lock yourself too tight on the Aesthetix train, I hope you can try other models in your system vs. the UII.

As for the Stealth, when the Io and Manley Ref DAC return from their GNSC updates, and the JL-3s back from their mods, I will be ready to try some of the Stealth Dream/Indra vs the Dominus throughout the system. I will certainly let you know how that all works out.

John

Hi Bart - I have the JL-3 Sig but the original (MK I), not the MK II. The JL-3 Sig MK II like the JL-2 Sig has many passive component updates which could lead to major improvements in midrange and treble clarity and resolution.

In a recent upgrade of my Aesthetix Io at GNSC with many capacitor changes, these same improvements were heard in the upper octaves but there was also a significant improvement in the bass. This was the one area that I did not expect to benefit from these changes. So the component changes in the latest round of CAT amp updates might benefit in the same way.

It should be no surprise that the bass (and I would also suspect the dynamic contrasts) would be superior on the JL-3's simply due to their doubling of power tubes. And I believe the power supply in the JL-3 is beefier as well. And then take the same component changes to create the JL-3 Sig Mk II and it is no surprise that this model once again sits atop the product line. But even with all these upgrades, and benefits of the JL-3 over the JL-2, the original JL-2 amp is something I could easily live with and be very happy with forever. It truly is that good in what it does.

Maybe next year I will update my JL-3's as I want to focus on getting my system cables finalized. And then a little more effort into room treatments and component isolation. It may sound so incredible that I will not want to ship the amps off for the upgrade at all. Perhaps a super-duper tonearm upgrade would make more sense. It just never ends.

Funny guy you are, sirspeedy and Brian too. But you know something guys, I really am close. I am pretty sure that anyone out there with one of the CAT amps has a weaker link in their system than the amp. So there's little need to fuss over moving up to a Signature or Mk II etc. If a CAT amp needs to be sent back to the factory for a repair, then an upgrade could also make sense while the unit is there....otherwise I am very fine to leave my CAT alone.

As for upgrading other components, I am content here too. Look at all the fuss with the digital stuff: EMM, Esoteric, MBL, etc. These guys are spending a fortune for upgrades here. I may be running with a 10 year-old Manley Ref DAC, but what Steve Huntley at GNSC just did to this thing for under $1k is nothing short of a miracle. An update with a ton of coupling caps, a couple of signal-cap value changes in the audio circuit, some line filtering, output stage filtering, chassis damping, etc., this thing can so easily compete again with the $10-20k units out there. Even Steve said when he heard this, "where did you get this thing?" He too was mightily impressed...and equally surprised at the results after his first level of updates. And he has seen and heard all the good stuff come across his bench.

And just last week he did the same with the first pass on my Aesthetix Io. And again, for under $1k. You don't get this kind of component upgrade performance for under $5k when you change to another component.

I feel I have found a handful of products out there now that are incredibly musical. Each of them had some areas that their competition outperformed. But the core of the sound of the products I chose did something very right at the start. And now I have discovered what a master engineer can do to some of these products, by addressing some weak points that were due to cost-cutting measures before. And in 5 years when the next generation of high-performance passive components come along, I will consider this option again. I'm pretty much done with these silly $5-10k component changes. They just don't make sense any more - the recent upgrade experiences have made this very clear to me.

The size and heat and tube costs for the CATs are a pain. The size of the SoundLab speakers are a bit of a pain....and the need to tweak their bias and calibrate their levels when the weather (seasonal) changes. The multitude of chassis for the Aesthetix and all their tubes are a pain. But only when something comes along that matches these components' performance and resolves these issues will I change anything. Yep, I am a very happy camper now. I need to replace my aging Clearaudio linear tonearm and resolve some remaining cable issues and that's it. If only I had a bigger room! Sigh.

John