Please help me with a Cary Audio tube question

you could wait for a response,
OR just Call????

If you want a KT-90 amp, then why not sell the CAD-40M Signatures and buy the design that you really are after?

You'll probably spend less money, and end up with a better result.

I can understand your desire to move away from those tubby EL34's. They certainly aren't my favorite power tube, either.

I am living in a country (Denmark in europe), where it is impossible to find other Cary Audio!!!!!
So if it doesn't need big changed, i would try KT 88/90 or if it need big changed I will keep the EL34

I have previously inquired about what I believe to be the same amplifiers as yours - with the same question. My concern was not having enough power to drive the speakers I was intending on in the future.

I called Cary directly(you should try), and was put in touch with a very helpful, courteous, and knowledgeable gentleman. He informed me that this was no problem. The only issue was to make sure to bias the amp correctly for the type of tube.

Why do you want to change tubes in your sweet sounding Cary´s?
In my opinion it´s one of the best compromises between transistor- and tubesound. I have a pair myself, and coldn´t dream of doing anything. They´re as perfekt as can be!