MXL 550 Mods
The MXL 550 is an entry-level condenser mic that could perform much better than it does. Its front-end circuit is compromised by questionable design choices and noisy parts. Its capsule is hit-or-miss; some sound decent, but most do not.
We offer two modification/upgrade options for the 550: capsule replacements, and a full circuit replacement.
Most of the tone of this microphone comes from its capsule. The 550 is severely compromised in this respect; the MXL small-diaphragm capsules vary widely in tolerances and quality. Maybe yours sounds great, but chances are it doesn't stand up to professional gear. All of the Chinese SDC capsules we've measured had a 3-5dB dip around 9kHz, and a sharp 3-6dB boost around 15kHz -- not a recipe for great sound.
Our line of premium replacement capsules will re-voice your mic, giving you a much smoother and more musically useful sound. Replacing the stock capsule with one of our large-diaphragm capsules will lower the mic's self-noise too. And it can be replaced by soldering just two wires.
If you are keeping the stock circuit in your 550, we would recommend replacing the capsule with either the RK-47 or RK7. Both make wonderful all-purpose microphones, with great detail in the mids, and a neutral to dark top end — a welcome contrast to most over-bright condensers.
Our premier upgrade for all generations of MXL 550 is the MP-V57 PCB kit, which gives you a perfectly optimized, high sensitivity, low-noise circuit. Build it with either an internal Cardioid/Omni switch, or an internal -10dB pad.
Because the circuit provides the option for corrective high-frequency EQ, you can use any of our large-diaphragm capsules with the MP-V57 PCB kit, giving your SP1 a wide palette of possible sonic colors.
This circuit is no arbitrary bag of parts, but rather a handpicked collection of carefully selected parts that was developed over several years' worth of R&D.
The PCB set fits the MXL 550 and numerous similar FET condensers. Click for more info on the MP-V57 PCB kit.