KT66: very dynamic

I play mostly thru my new (used) Marshall 2266 amp. loaded with 2xKT66 in power section. very dynamic and responsive to pick attack.

No Mesa amps with KT66 stock? Can you replace 6L6 (same family) with KT66 in a Mesa amp? or would you actually have to re-bias, which you can't (i.e. screwed!)

you can use KT 66's if you find a set that are within the mesa range (mA) for your amp. or swap out one resistor to adjust the bias correctly.

scott

That would be an interesting configuration. KT66's in a Mesa.....Triple Recto?? :?:

zodiac272 said:

you can use KT 66's if you find a set that are within the mesa range (mA) for your amp. or swap out one resistor to adjust the bias correctly.

scott

Click to expand...

Well, would Mesas be able to accept the higher current draw from those KT66s???

I just called eurotubes and the guy said that it's safe to plug-n-play a KT66 in a 6L6 spot b/c the amps are typically biased so cold, it can't harm anything.

Most likely if you call Mesa they'll say it will void your warranty and they want you to buy their tubes anyways to maximize profit.

Try it, you'll like it (except for the price: KT66 is very expensive!)

I'm not too sure about that. Eurotubes has always said many amps would be able to run with KT66s and KT88s, but some people apparently has had problems doing so. I would just like a larger consensus to make sure that it is definitely safe to do so...

Just bear in mind that putting in KT66s won't necessarily mean you'll get the dynamics and response of a Vintage Modern.
The VM is one hell of a special amp and if the JVM didn't exist, I would probably end up owning one.

I doubt it's just the tubes that are guilty for that kind of response. It's like expecting to get a Mesa-like tone from a Marshall just because it's loaded with 6L6s (yeah, I know, that old moldy analogy, but it sorta applies here too).

There's not a huge amount of difference between max plate current draw/dissipation of a modern production kt66 and a modern 6l6gc. The heater current is similar to what is drawn by an el34, slightly more than a 6l6 type. I'm pretty sure that the power tube sockets need pins one and eight connected together like for el34. Finally, I'd install or have installed one of the new adjustable bias pot "mini boards" found on ebay instead of changing out that bias resistor if your amp can use such a thing. Voids the warranty though.

My Maverick needed something special in design to pull off the adjustable bias thang but it was worth the effort. It's long out of warranty.