JeffB Posted April 25, 2010 Share Posted April 25, 2010 Ive got an 81-82 Rivera designed Fender Concert I have owned for years. I just converted it to a head and while installing it in to the headshell I noticed that the volts selector was set to 260 not 240. I dont know how long its been set to 260. I didnt do it and its not a button that can be easily bumped. So its beyond me how it got there. I have let other people use this amp at different times though. Any thoughts on what damage may have occurred, if any, from having it being on this setting? It works and sounds great. Thanks Link to comment Share on other sites More sharing options...
mars_hall Posted April 25, 2010 Share Posted April 25, 2010 Don't think it would hurt the amp at all. The selector switch usually just send the input to a different tap on the transformer windings (fewer windings for higher voltage input) , resulting in a lower voltage on the output side of the transformer. Eddie Van Halen used to use a variac to apply lower voltage to his amp and change the tone. I don't think you would ever want to change the selector to less than correct input as this will have the opposite effect (higher voltage on the output side of the transformer). Think pyro-effects ;P Others should probably chime in Link to comment Share on other sites More sharing options...
mars_hall Posted April 25, 2010 Share Posted April 25, 2010 Lower input voltage Link to comment Share on other sites More sharing options...
MuDBoNe Posted April 25, 2010 Share Posted April 25, 2010 I build amps and modify amps as a hobby. I had a 1981 Fender "75" with the same power transformer. These amps from that era were running about 500 volts on the plates of the tubes. Dropping the voltage would not hurt anything at all, and probably give you some extra power tube life. If you put it back to 240, it will tighten up the amp sound giving you a bit more headroom. Link to comment Share on other sites More sharing options...
212Mavguy Posted April 25, 2010 Share Posted April 25, 2010 One not so good effect from variac-ing an amp is the possibility among other things that the tubes are forced to run with the heaters/cathodes at too low voltage/temperatures, if the variac is set for too low of a voltage going into the amp. In this case there's less than 10% difference in voltage going into the amp so heater voltage difference would not be enough to cause a problem, no problem with this minor thang at all. Link to comment Share on other sites More sharing options...
JeffB Posted April 26, 2010 Author Share Posted April 26, 2010 Thanks for the replies. I learnt somethings. The amp sounds and works fine. Link to comment Share on other sites More sharing options...
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