Tip: Turn off the Noise Gate
I bought a Line 6 Spider 15 watt amp 2nd hand, like many people do. It was my fist modelling amp, and the layered ramped up tone controls took some getting used to. They are not linear 1-10, they have three levels within each control, each a little more potent.
I like the built in effects but I felt something was missing from the sound, like part of the spectrum was left off. I did find out how to default the amp with a quick google search but it was only after 6 months and finding the manual to find the answer to why muffled picking sounded so so dead.
Tip 1
If you want all of your dynamic range, turn off the built in noise gate! If you want to emulate old U2 for instance, until this is turned off, you guitar will sound muffled and dead. This also makes a huge difference if using the amp as a preamp to a a guitar sim. With this turned on, you will always have a higher tome with very little bass compared to other small amps wither everything tuned to 0, just as a preamp for the online amp. The online amps needs a good signal, the noise gate interferes with the tonal spectrum.
To turn off: Hold down the TAP DELAY button while the "B" effect know (sweep, echo reverb), to the reverb setting, or all the way up. You should hear a little background noise that has been hushed by the noise gate.
Noise gates have their purpose, but it should not be on without the users knowledge as it does take away sounds. This is not a problem for owners that bought them new and realize this, but the rest of us might not know. It took me several months before I was convinved some sort of built in device was hurting the sound for what I used it for. Sure enough I was correct.
TIP 2
Download the manual!