[dolsey01]

Originally Posted by NB_Dude

I just recently joined this AA.org after stumbling onto these great manufacturer forums. My VSi75 has its original Kt120s and its coming up on replacement time, which i understand is suggested to be at or before 2000 hours.

Now, i see some folks have been debating the subject and some indicated they have indeed replaced the KT120 tubes with KT150s but I had emailed ARC specifically on this subject last winter and they indicated:

"..The KT150's will not work in that unit because it isn't made to handle that high of heat. Please remember bigger isn't always better. The unit was designed around the KT120's .."

Just thought I'd share this....

Paul

I guess they changed their tune, this image is from their product page showing the VSI75 with KT150s:

And this is their description:
Performance-wise, the VSi75 is in an entirely different league for a number of reasons. It has a new power transformer that was designed around the KT150 output tube. The VSi75’s wide bandwidth output transformers are the same as those in the remarkable Reference 75, and we also incorporate some key REF75 parts including proprietary coupling caps. And, we doubled the bulk power supply caps.