Focusrite CM25 Mods

The Focusrite CM-25 (aka Scarlett) mic is a small diaphragm condenser in a large-diaphragm mic body.


The mic isn't actually terrible. It avoids most of the sins of cheap condenser mics. The circuit is a through-hole design made with generic but not awful parts. The capsule, while tiny (like 16mm diameter), isn't painfully bright or sharp or thin.

The mic is one you'll outgrow quickly, though. And because the metalwork is pretty nice, we recommend replacing the mic's capsule and circuit with upgraded parts.

TSB-2555 capsule with harness

First, replace the capsule with our TSB-2555. The capsule includes our custom-designed harness, plus all the screws and wires needed for installation.

ETL1 Circuit Kit

Next, replace the mic's circuit. We offer two options.

The first is called the ETL1. This is a premium implementation of the Schoeps CMC5 design, adapted for use with the TSB capsule. It is uncompromising in its parts selection, and impressive in its performance, thanks to its carefully selected and biased NOS JFET, imported polypropylene signal caps, and low-noise parts throughout.

Note too that the circuit board has a pad switch. To access it, remove the mic body. (There is no easy way to make it accessible from outside the microphone.) With the pad engaged, the modified CM-25 makes a formidable close mic for toms.

Read more about the ETL1 circuit kit.

EXF1 Circuit

The second circuit choice is the EXF1. This is a transformer-coupled circuit design based on the Neumann KM84. We designed this circuit to produce a rich sonic character, giving it the saturated texture more often associated with tube gear. It also creates a mild compression effect on sharp transients (again, like vintage tube/transformer gear).

Like the ETL1, the EXF1 contains a pad switch on the PCB. Remove the mic body to access it.

The EXF1 is easier to build than the ETL1, but both have been successfully built by first-time DIY kit builders.

Read more about the EXF1 circuit kit.