Grace Design Felix Acoustic Instrument Preamp (Discontinued) Leave a Comment / Uncategorized / By Alexander / September 22, 2017 90 GEARANK 90 out of 100. Incorporating 20+ ratings and reviews. Street Price: $1075.00 Manufacturer: Grace Design Features: XLR Input Two 1/4″ Inputs 48V Phantom Power EQ Hi/Low Shelving Parametric Mids Sweepable HPF Per Channel TRS Insert