Can a Matchless Clubman handle KT66s?

I would leave the Clubman alone. If you want a KT66 amp buy a Route 66

 

The heater currents are almost the same (EL34 1.5A, KT66 1.3A) so that part is fine. Output Z is similar, but that's not super critical so no big deal there. A socket wired for EL34s can accept KT66s. Where you're going to run into problems I think is (1) the cathode resistor is too low, which will cause the KT66s to run too hot, (2) size: KT66s are approx. 3/4" larger in diameter than an EL34, which means you need at least 2-1/4" (and preferably 3") between sockets (center to center).

 

v-verb-i rember phil jamison (spelling?) debunking some hc posting that said you could swap the el 34s for 6l6s- he said this would kill the OT. just in case thats where you were going next!
but...
what about swaping the ef86 for the original pre amp tube?
i love my clubman (94) but allways wanted to hear the original version. does anyone know if this could be done?

 

I had a Clubman many moons ago. I had an open input jack, and I called Matchless for help. I spoke to Rick, and he walked me through the quick fix. As an aside, he said, "Ever put 6L6s in your Clubman?" I hadn't but he assured me it was cool. I never tried it, because I like the EL34s so much. In hindsight I'm glad I didn't get transgenic with my Clubman's output tubes. I'd hate to have fried an OT.

Sam

 

Not without modifications
The amp can handle it, could even handle KT88's.
But, you'll need to change the cathode resistor
for either tube.

 

MR Roccaforte, any info or thoughts on changing the the ef86 to the original pre amp tube- i forget wich one that was. i know you have worked on clubmans from your past post.

 

The last I owned had an all triode preamp,
the was an extra single triode stage of gain
used to bump the front end.
Personally, I'm not a big EF86 fan, but
the Clubmans sound good with either preamp.
I would leave it alone. Doug

 

thank you

 

In a cathode biased circuit these two tubes bias very differently and the screens of a EL34 is going to look to push about 8 watts and the 66 will try this and fail in short order.

Do not do this.

 

Forgive me for my ignorance, but is it possible to put a solid state rectifier in a Clubman? If so, has anyone tried this?