Just saw and thought I’d add my experience to the mix here.
I picked up a used Ref 75 from my local ARC dealer about 2 months ago. I was told at the time that it has a lot of hours on it, and that a fresh set of tubes would be a good idea, and that it would be a good idea to make the switch to running KT150’s.
I felt uncomfortable about just swapping out the tubes, without doing the full SE upgrade, so I did not do it.
A little while later it blew a fuse, so I took it back to the shop I bought it from to see if it was indeed just the fuse, or something else. When I got down there we had a great conversation about upgrading to the SE version or just switching to KT150’s. They recommended a call to George Meyer the local ARC service center, to get their input on it.
So that’s what I did. George Meyer’s tech was great. He said that yes indeed, just switching to the KT150’s was a good improvement to make.
So I did. George Meyer put in the new KT150’s, and found the cause of my amp’s blowing the fuse. To say they did a great job would be to make a real understatement. Fantastic service. It was done and ready to go in less than a week. Of course the amp just sounds fabulous.
So bottom line is, since ARC's LA service center recommend the switch to KT150’s, without going the full SE upgrade path, I see no reason not to do it. George Meyer is an authorized ARC service center, and I certainly trust them. Hope this helps.
