For review I received the Spider IV 75, the #1 selling 75-watt amp in the U.S. It has 16 amp models selectable by a single knob--they are divided into two different styles for each model. There are over 300 presets designed by artists like Slipknot, As I Lay Dying, and Killswitch Engage.

Spider IV 75 uses a twelve-inch C12P-80 custom-designed Celestion® 8-ohm speaker with a 2-inch tweeter. The Spider IV 75 interfaces to a Line 6 FBV Shortboard MkII foot controller (optional) via a standard Ethernet network Cat-5 cable. The FBV Shortboard is not mandatory for operation as all controls are available on the front panel. In addition, the FBV has a USB socket for connecting to your computer for editing and organizing your sounds using the Spider Edit software. You may also trade tones at CustomTone.com.

I found the number of possible sounds endless and programming them easy and intuitive--the manual is just two pages of information. I liken the Spider IV 75 to a Swiss Army knife of guitar sounds--there are so many tonal styles here and also 20 popular effect treatments. There is a free firmware update that ups the total FX count to 76 but you'll need to have the Line 6 FBV Express MkII or Shortboard MkII to make that happen.

I especially liked the recording feature where you can record a loop and overdub--sound-on-sound-style. Once you have a loop recorded into memory, you can experiment with hearing the loop played through any of the different models. Of special note is the built-in reverb: your choice of a spring or hall reverberator. But the freeware Spider FX Infusion v2.0 upgrades that up to 6 reverbs.