2. amps-preamps
  3. 1311914841

Questions About CAT JC-2

Those of you who know this amp can perhaps answer some of these questions:

1) What is the input impendance (not listed on CAT's website). Is it compatable with long IC cable runs?

2) I hear that tube biasing is for each channel at a time, rather than for individual tubes. Is that correct (bias all 8 tubes together). Does that mean you have to stick to sets of 8 matched tubes? If one blows, do you typically end up replacing all 8, or can you just replace the one?

3) Does it work with other tubes besides 6550's like KT-88's and KT-90's. What tubes do people have the most success with?

4) I'm looking at an earlier JC-2, not the signature version. I realize there have been steps along this amp's evolution. This one atleast has the 10 resistors rather than the 6, so is less susceptable to blowing out. In general, how quiet is this generation JC-2?

5) I'd be using this with Avalon Indras. I've heard that the CAT is a good match with Avalons. Any thoughts on that?

Thanks, Peter
peter_s

Showing 2 responses by peter_s

peter_s OP
1,319 posts
 
I did get a bit of info from CAT.

The input impedance is 110 Kohms

As for replacing a blown tube, Lee said that one should replace the whole set if they are getting close to worn out, but if they are still in pretty good shape and the "blown" tube seems to have blown early in its life, it would be OK to replace just the one.

A set of tubes should last 2000 hours.
peter_s OP
1,319 posts
 
Thanks Jafox,

Yep, that was a typo. Meant to type JL-2.

My understanding is that the original JL-2 began with 6 resistors, then up to 10, and like you say, there is now a newer resistor set which supposedly allow the amps to better handle a catastrophic tube failure.

In order to protect against having to buy a whole new set of tubes if just one blows, I'm thinking about buying a couple extras, and rotating them through as the tube set ages. This would mean that I'd always have a couple around that are similarly aged as the rest, if a replacement is needed.

Are you half kidding about not leaving the room? With the new resistor sets, is it sufficiently safe not to worry about torching?
More to discover