twothemax
Well-known member
some preamp tubes provide different gain depending what they are used for. 12ax7a is the highest gain. power tubes should be matched for best performance. a 100 watt amp should be replaced with a quartet and a 50 watt with a duet. this way they are matched. replacing one at a time is no cause for alarm, but is best to change your power tubes at the same time.
