Summit Audio's MPC-100A is a combination microphone pre-amp and compressor-limiter in a single, two rack space package. This single channel unit uses a tube microphone pre-amp with two inputs: a low impedance microphone input with phantom powering and an Hi-Z input for musical instruments like a bass guitar or synthesizer. There is a unique "loading control" that optimizes or matches the pre-amp's input impedance with the output impedance of whatever you have plugged into it. The instrument input is electronically balanced while the low impedance input uses a Jensen input transformer. Maximum input level is +25dBu.

The tube compressor/limiter section comprises the other half of the Summit MPC-100A recording chain. There are variable threshold and release controls and also pre-set attack and release switches. A clip indicator shows when the compresor circuit input is overloading. However, you may set the gain structure between the mic pre section and the compressor section so that a certain amount of tube saturation can be imparted on the finish sound. Once the desire overdriven sound is achieved, the overall output gain control sets the actual recording level to your master tape deck. The maximum output level of the MPC is +25dBu into a 75 ohm load impedance and Summit's famed 990 discrete operational amplifier is used in this final, transformerless stage.