Written by DBE intern, Elena Klinova.
You can hear sound clips of this and other reviewed pieces of gear here: https://jordantishler.wordpress.com/gear-review-clips/
Starting with the signal flow, there are two sections, as implying by its name, a mic preamp and a compressor. To get the signal inside we use preamp section with DI input on the front panel and line or mic inputs on the back panel. There is a front panel 48 volt switch for a condenser microphone. If you use the DI you can adjust the impedance as might be appropriate for a guitar or keyboard. Once inside, signal goes through the gain amplifier which can change the sound entirely. Even at moderate gain, the MPC-100A will add some warm tube saturation to the sound. If you push the signal level it starts to sound more convex and gritty. In fact, it adds certain amount of distortion to the sound which can be pleasant for some instruments and not very good for others.
By the way, there is a bypass switch on the front panel but it works only for compressor so the sound will go through the pre-amp gain anyway. But if you didn’t want this amplifier to work then you wouldn’t have inserted it into the chain, would you? Also this section has a LED indicator showing when the tubes saturate, and phase and pad switches that can be handy in some situations.
The next section is the compressor/limiter with it’s own gain and LED indicator. Along with output switch, this stage becomes a powerful tool to control the level and saturation of the sound. There are also the usual parameters that you can adjust: threshold, slope (ratio), attack and release time. In addition the link switch allows you to use two MPC-100A in a pair.
For me, if you want to use this piece of gear properly you should drive the tubes. I would prefer to chose a signal which would love saturation or distortion. It could be bass or electric guitar or anything that needs more grit in the sound. Probably I wouldn’t use it for smooth sounds and vocals since you’ll end up with a too soft or too distorted sound.
JT adds: The MPC-100A is a beast on bass, kick, snare, guitar, and occasionally keys. Its function ranges from moderate warmth to full on distortion. It’s just not a subtle piece. That’s why I love it. Elena is right, we use it on every session.