Consider the following scenario to illustrate why people think the tubes that they recently had installed in their amplifier whether it be for a guitar amplifier, a bass amplifier, or any other type of tube amplifier are so much better than the brand they had in there before. (In other words how tube rumors get started)
Most people do not change their tubes until they have a repair issue. We find that on a average most tube amplifiers we take in for repair have not had their tubes changed for 2-3 years ! After 2-3 years any set of tubes are not going to sound good in your amplifier. So pretty much no matter what tube is installed now will sound so much better that what you had that you will think the new tubes are best thing since sliced bread. In other words it is not so much the brand of tube that you installed, but the fact that you changed the tubes at all that made the amp sound so much better.
Randy Morgan ….. Owner & head technician at All Service Musical Electronics Repair