Name:    Steve Kennedy
Email:   steve@pacair.com  
Subject: 112 rp.........6L6s or EL84s?
Thread:  61
Time:    Wed, 25 Apr 2001 03:08:19 GMT

I am guessing that you have a pre-1980 112RP-65 with silver badges. The black badges were phased in in the 80's, and the RD series was upgraded to 100 watts.


I owned a brand new 1979 112RD-65 myself and it was a marvelous amplifier that NEVER let me down and I NEVER replaced the original Sylvania 6CA7 output tubes in the 4 years I used that amp (used quite alot... at least 3-4 times a week).


The RD-65 amps, like all the pre-1980 models, were based on the 6CA7 tube, which are hard to get and expensive when you can get them so they are commonly substituted with EL34 types... NOT the little EL84 you suggested (I make that typo mistake too from time to time!).


6L6 tubes could probably be substituted but at least a rebiasing job would have to happen. I personally haven't done this but I have seen amps which have had their output tube types swapped like this and they work fine and sound a bit different than before.


This is essentially all that Music Man did when they "upgraded" the amps to 6L6 100 watts. I am sure that they did this because the 6L6 tube was much more available than the 6CA7 by 1980.


Steve