Ampex MX-35

We have two of these 4 channel 2-bus mic/line pres in Studio B. We built a control box for these which puts phantom power, phase reverse, and a -20dB pad before the mixer's input. They have a classic early 1960s sound reminiscent of early Motown and Beach Boys recordings. They don't have a ton of headroom, and the frequency response isn't perfect, but so what. When used with transformerless condenser microphones with low output impedance (less than 100 ohms) you may need to use the pad to properly terminate the input transformer and prevent distortion. They been modified (output fader bypassed) to dramatically increase performance when terminated with normal studio input impedances.