radial engineering prormp studio re-amper passive re-amping direct box radial engineering the radial engineering prormp is a 100% passive re-amplifier that takes a prerecorded track and re-amplifies it through a guitar amp or effects pedal creating new and exciting tones. re-amping has been the "secret weapon" for countless recordings by the biggest names in the business and the process is often used on guitars, bass, keyboards, percussion, and even voice to create new textures! plug and play and easy to use, the prormp studio direct box connects from the recorder to your amp and effects units and does all the impedance matching for you. just adjust the level to suit!the magic behind the radial engineering prormp's great tone is a custom-wound transformer that at once converts the balanced low-z source to a hi-z input for your amp while also acting as an electrical isolator to eliminate troublesome ground loops that can often cause buzz and hum in the sound.like all radial products, the prormp is built tough. encased in a 14 gauge steel, the prormp employs a unique bookend design with a welded i-beam frame that protects it from damage and assures the pc board and solder points will not be stressed, adding durability. a full-bottom no-slip pad works double duty by providing plenty of stay put while also eliminating electrical contact points from guitar amp chassis bolts that could cause ground loops.the radial prormp direct box gives you affordable professional re-amping for every recording studio.prormp applicationplug a standard balanced cable from your recorder or mixer output to the prormp's xlr input. connect the 1/4" prormp output to your instrument amp. adjust the prormp's output level control as required to match the amp input and engage the ground lift switch to eliminate any hum and buzz caused by ground loops.