Was wondering if anyone has done any comparison of the smooth vs. ribbed plate Teles in their gear. I've compared a variety of 12ax7s in my phono stage (Ampex, Mullard, Tele, stock new reissue Tungsol, Siemens dual post) but stopped at the rib plate Teles since they sounded so good. Should I have gone on to listen to the smooth plates?
Hi Myles:
I have compare the ribbed and smooth Tele's and many other 12ax7/5751 as input tubes for my Rogue Audio amp. This position is very sensitive to tube changes. At first I thought the ribbed plate was the superior tube--it just seems to have more detail and high end shimmer. Now I m not so sure. The rib can seem a little relentless at times, almost as if it is emphasizing the leading edge of the music . The smooth plate is, er, smoother. More even handed and flowing. Both are good tubes, but IMO (in my amp) neither is close to the best 12ax7. The good news for those who pay the high asking prices is that they are a very well made, long lasting tubes. I have collected over 2 dozen of them, and never had a weak testing one, or one with a large imbalance between the triodes. I have one old rib that was obviously abused, it has burn marks in several places but it still tests perfect. I believe these tubes have a 10,000 hour life span (at least).