Ampeg pedal preamp with built-in and user loadable IR ‘s. It’s sounds good but not great, the factory IR’s are dull, I think it’s because of the EQ (hi pass and low pass filters should be switched off in the software). With 3rd party IR it starts to sound better, however the BassRig still beats its. Ampeg V3 head that allegedly utilizes the same preamp circuitry sounds phenomenal, so it must be the DI/IR section that makes the difference. Build quality is excellent.