Positive Grid | 1 decade ago

BIAS is an Amp Designer, Modeler and Processor for iPad. It's warm, accurate and more versatile than any other modeler, processor in hardware or software ever created.

BIAS starts with stunning replications of 36 of the most sought-after vintage and modern amps in rock 'n' roll history and then lets you customize them to respond perfectly to your unique touch and feel. Swap out the tubes, preamp, transformer, tone stacks, cab and mic—even change the tube's bias—to create your dream amp and distinctive signature sound. Tap once to open your BIAS amp in JamUp and add awesome multi-effects.

http://www.positivegrid.com/bias