Most amp problems, ie: microphonic squeals, crackling, low power, mushy bass response etc... can be traced to bad or weak tubes. Remember, tubes are like car tires, they get worn out through use and need to be replaced. Sometimes they can go bad very quickly, even when new. Just as a light bulb works great one day and it blows the next time you hit the power switch, it's unfortunate but a fact of tube life. How loud you play and how long you play for affects how often you need to re-tube your amp. If you play alot, changing the power tubes once a year is normal, pre-amp tubes can often last twice as long, even longer.

When changing power tubes you should use a matched set of SVETLANA brand power tubes. As always biasing these tubes is a good idea for optimum tone. SVETLANA tubes are very well made and can reliably handle our high-power circuit designs, other newer brands of tubes may work but our tests show SVETLANA allow you to plug in a new set, adjust bia if needed and get back to making music fast!. CHINESE 12ax7 pre-amp tubes work great to maintain the original tone of your amp. SEAN'S TIP: Keep an extra set of tubes around, tubes always seem to go bad when you have that really big gig at the FORUM!