KT-120s in a c-j Premier 11A

Xti16,

Took your advice and called c-j and got Ed's voicemail in customer service. Left him a message about wanting to use the KT-120s in my 11A but haven't heard back from him yet.

If I do, I'll post his response.

Myles,

I've used the KT-120s in my Premier 140 and didn't have any problems but the 140 is currently out of commission which is why the 11A is back on active duty. Since it's an older unit with aging parts, I was hesitant to just plug in the 120s without getting c-j's blessing. I hope Ed gets back to me before I do something irresponsible like just try them out.

I took a look at your system. Wow! I'm sure it sounds just wonderful.

Thank you both for taking the time to respond to my query.

Regards,

I went ahead and tried them in the 11A. They've been running about 7 hours now without any issues so far. The transformer casing may be running slightly hotter than normal or it could be just my imagination. They sound pretty darn good: kind of a cross between the richness of a KT-88 and the detail of a 6550 but not to the full extent of either.

For a current production tube, they're quite good. Not a vintage Tung-Sol but then what is, except the original?

I agree regarding the Tung-Sol black plates. If I had to pick just one tube to live with from now on, that'd be it. The solid and three hole grey plates aren't too shabby either.

I've never been lucky enough to hear the EAT KT-88s but their reputation precedes them. They're as expensive as vintage Tung-Sol and Genalex though.

We'll see how long the KT-120s remain in the 11A before audiophilia nervosa sets in and something else replaces them.

Hi Jedinite24,

I had them in the 11A and they were never an issue. I did eventually get a hold of c-j customer service and was told it was okay to use them. Although they run at a higher heater current (1.8 amps) than most current production tubes, the 11A was designed and voiced around the GE 6550A which runs at the same heater current. Vintage Tung-Sol 6550s also run at 1.8 amps and I'd previously had both the T-S 6550s and the GE 6550As in the unit without any issues.

conrad-johnson is now supplying all of their current production amps with the KT120 and both Lew Johnson and Bill Conrad have both been quoted as really liking this tube. That opinion seems to be shared by most c-j owners, too.

I like the tube, but it seems I'm in a small minority of users, maybe just me, actually :) who prefer other tubes in my c-j amps. The New Sensor Tung-Sol 6550 and New Sensor Gold Lion KT88 being two current production output tubes that I prefer.

The KT120 is smooth sounding with excellent imaging. It has a solid bass response and the treble is generally also good. However, I find it a little lacking at the very top and in my opinion, it also lacks a little of the upper midrange, lower treble clarity of a good 6550.

Just my opinion naturally and I want to restate that I seem to be in the minority.