I have been usung the ’63 Vibroverb Reissue ever sine I bought it new, in 1992. Never a problem mechanically.. I have been using all Groove Tubes for all the preamp tubes, since it was still almost new. And the 6L6s are the older Svetlana “Winged ‘C’” power tubes. All of the original tubes were Chinese, and some people gave them bad reviews, so I just replaced them all. The hugest improvement on sound was when I put a pair of new 10 inch Eminence 1028-K, [ALNICO], speakers in it… It was as if I took a thick wool blanket off it. It is the perfect amp for me. It sounds really good either at very low volumes or at very high volumes. I am always getting compliments on it’s TONE, when playing out with my 50s-60s R&R Band…..