CAT JL-3 Versus VAC phi 300.1 monos?

Jwn's comments ring true. The CAT is great amp for all sorts of speakers, but it is the tube amp I would choose for speakers that generally need SS to sound their best, they have power current and can really control bass drivers for a tube amp and in absolute terms as well. I don't mean this as faint praise, it also sounds great with most anything you drive with it.

The VAC may be easier to maintain. When I had the 300.1, a power tube went out and amp was still able to play music despite increased background noise. Switched the tube and problem was gone. With the CAT, there is a chance you may need new resistors. The bass is better running 300.1 monos.

I also have a pair of VAC 300.1s and have had them for a little over a year now. They don't run as hot as I thought they would, and it is a very small price to pay for the great sound others have described above. I've heard CAT amps at shows and while they also put out great sound, there seemed to be considerably more heat generated than from my 300.1s at home.

I also agree that the bass gets considerably fuller, faster and more palpable with 2 300.1s as opposed to just 1.

IMHO, CAT stands above all in the amp dept, preamps are great but not the best...German press praised Cat amps 10 years in a row as best amp in the world!
These guys have MBl among other German brands in their back yard!

Choose your speakers first, then the amps. MBL and Avalon are very different from each other. No sense in putting the cart before the horse.