Apex 430 Mods

Apex 430 microphone

Several different microphones have been sold under the name "Apex 430." The one we've seen has two circuit boards and a transformer. It is a variation on the MXL 2001/V67G, in that the circuit borrows from the U87. Nonetheless, the mic manages to sound peaky and over-bright on most sources, because the high-frequency corrective EQ is not implemented properly.

We have three modification options for the 2-PCB version of the Apex 430. (If your 430 has only 1 circuit board, you could still upgrade the capsule, as noted below.)

#1: Capsule Replacement


The stock Apex capsule is a 32mm K67 style. These capsules are not very consistent in sound, but most tend to be peaky and harsh sounding.

We recommend replacing it with our RK-87, which is an upgraded version of the K67 design. We use thinner diaphragm material to improve articulation, and we tune the capsule to have a more neutral top end than the Neumann K67/K87.

Another option is our RK-12, which has a broader presence boost than the RK-87, and a warmer low frequency response. This capsule will give a very neutral top end on the Apex 420/430 platform, due to the circuit's corrective EQ.

MP-V57 PCB kit

#2: Transformerless Circuit Replacement

The stock Apex 420/430 circuit is underpowered (~34VDC at the capsule) and prone to distortion. Rather than make a few component changes to fix the worst parts of it, we've developed an entire PCB replacement kit.

The new circuit is transformerless; it's a highly optimized version of the circuit in the famous Schoeps CMC-5 microphone. It gives you a very high-sensitivity, low-noise, low-distortion microphone with a pristine, clean, uncolored sound.

With a replacement capsule, this circuit mod also gives you an internal switch that can be used for pattern control (Cardioid/Omni). Alternatively, configure the switch as a -10dB pad.

The photo at right shows the new circuit, which uses two high-quality two-layer PCBs manufactured in the US. This kit fits the MXL 2001 and numerous other models.

Click for more info on the MP-V57 PCB kit.

T-84 Circuit kit

#3: Transformer Circuit Replacement

If you like the idea of keeping a transformer in your microphone, consider our T-84 kit. Based on Neumann's KM84 circuit, the T-84 will provide significant sonic upgrades to your microphone: higher sensitivity, lower noise, lower distortion, superior tone.

Internal switches give your mic a second polar pattern (Omni) as well as a 10dB pad.

We recommend installing the RK-47 or RK-12 capsule with this circuit.

The photo at right shows the new circuit, which uses two high-quality two-layer PCBs manufactured in the US. This kit fits the Apex 420, 430, and most other MXL 2001/V67G types.

Click for more info on the T-84 circuit kit.