Differences in KT-66's and KT-88's and 6L6GC

[xT00BZRG00Dx]

I'm thinkin' of getting a quad of JJ KT-66's or KT-88's. Can they be used in a Mark III without mods, and what differences would they make over 6L6's? Also, what are the differences between KT-88' and KT-66's?

 

[crane]

I think KT66 can be used instead of 6L6GC, but not KT88 !

 

[dmt]

I've used KT-66's for a long time, so long I've forgotten how 6L6's sound...

1. Make sure they are not Sovtek KT66's, those are really 6L6 WXT+ guts in a big bottle. Not the real thing.
2. If you can find Svetlana KT66's ( Groove Tubes used to relabel them as GT KT66-HP, but they no longer make them)
3. If you run Class A, use Tweed mode, I've found in my amp that the tubes redplate otherwise.

Sound-wise they are fat and chunky. They have a nice tight low end, not muddy. They are pretty warm sounding. I've been saying that I'll try out a set of =SED= 6L6's to compare at somepoint, but I just love the KT-66's so much I've never got around to it.

I use em in my Simul-Satellite and they are great. Just make sure if you buy em online from the tube store you tell em taht they need to be in the proper range for Boogies.

 

[stephen sawall]

Do not even put KT88 in your amp. I love KT88's but they are not in the range of tubes that can be used in your amp.

I used GT KT66-HP in my Mark IV for almost a year. They sound great for leads and clean with a huge low end. But they did not sound as tight as Winged C 6L6 for rhythm chunk stuff. So this is what is in mine most of the time now.