Apex 480 Mods
The Apex 480 is a 3-pattern FET/transformer microphone with switchable pad and filter. It uses a familiar 2-stage emitter follower circuit and a common 32mm K67 capsule. The result is peaky and harsh-sounding on most sources. We recommend replacing at least the capsule, and possibly also the circuit.
#1: Capsule Replacement
The stock capsule is a 32mm K67 type, found in just about every inexpensive large-diaphragm condenser microphone on the market. It has a peaky and uneven response that is not very musical, and tends to require EQ to fit into a mix.
We recommend replacing it with a K47 type, which will give a more neutral top-end response, with rich midrange detail. Our favorite capsule for this mic (assuming the stock circuit is retained) is the RK-47.
Another option is our RK-12. The voicing of this capsule is bright, but it sounds different than the stock GAP capsule; it has a smoother top-end response and warmer lows. It excels for female vocals.
#2: Circuit Replacement
The Apex 480 circuit is a 2-stage transistor design with a low-ratio output transformer. We don't care much for the design; the 2nd stage transistor seems to clip under moderate SPL, and the transformer is not adding any sonic value.
We've developed a version of the KM84 circuit, which is a linear single-stage JFET design with a very high-quality output transformer. We designed custom circuit boards for this circuit, to make room for the best-quality parts we could find. Customers say the results more than justify the cost.
Click for more info on what we call the Linear 87 Circuit kit.