Q: I cannot find the tuner feature on my Spider 15w, 30w, or HD75?
A: The tuner is not included on the Spider 15 watt, 30-watt combo, or 75-watt head.
Spider I: The tuner is only accessible by connecting the Line 6 Floorboard controller.
Q: When I am finished using the floorboard tuner and switch the tuner off, there is a load 'pop' that is heard through the amp?
A: This is not a problem with the floorboard. The Spider does this when you exit the tuner mode. The noise can't be eliminated entirely but there are a couple things you can try to do to minimize the noise.
1) When tuning, turn the volume pedal down all the way. After you exit tuner mode, wait a few seconds and then bring the volume pedal back up.
2) After tuning, let a few seconds of total silence (from your guitar) pass before exiting tuner mode.