AKG Perception 420 Mods

The AKG Perception 420 can be thought of as an affordable Neumann U87. It has the same circuit design, same capsule type, and the same switchable features. Yet the mic doesn't sound much like a U87 -- it is far too bright and peaky, rendering it "hyped" and sibilant on many sources.

There are several reasons for this, most of which would be difficult to correct. However, there is one change that is simple to make -- with a significant sonic impact:

#1: Capsule Replacement

We recommend replacing the AKG Perception 420 capsule with our RK-87. Although similar in architecture to the AKG version, the RK-87 has a lower-amplitude high-frequency peak and a smoother response. If you find your Perception 420 to have too much output in the 10–12kHz region, making the mic sound like every other cheap imported condenser, the RK-87 will fix it.

#2: Input Capacitor Upgrade

Our full mod kit for the Perception 420 includes an upgraded input capacitor. The stock microphone uses a generic ceramic part in this critical position. We supply a polystyrene film capacitor to replace it; these are among the most neutrally voiced audio capacitors, and are commonly found in premium condenser microphone designs.

If you are modifying a Perception 420, we strongly recommend the full mod kit. It costs only a few dollars more, and adds only about 15 minutes to the time needed for the mod.

Click through to the Perception Mod Kit page to see before-and-after frequency sweeps for this mod. See how both compare to a U87 Ai, too.