Review Demo - Keeley Compressor Plus

The serial number on the back of our review model Compressor Plus is 47061. But the digits don’t represent some cryptic in-house code. Oklahoma’s Robert Keeley Electronics has actually sold nearly 50,000 U.S.-made compressor pedals—a remarkable figure for an indie builder. The latest iteration of Keeley’s squeezebox is the Compressor Plus, which replicates the tones of earlier Keeley models while adding several meaningful new features: a blend control, a post-compression tone circuit, and a single-coil/humbucker toggle. It runs on standard 9V power, and there’s a battery compartment. Like most of Keeley’s compressors, the Plus is based on the 1970s Ross Compressor, which was itself a near-clone of the earlier MXR Dyna-Comp. (Really. I’ve got schematics for the Ross and MXR right here, and the “two” circuits are very similar.) Both pedals had just two knobs (compression amount and volume), where many full-featured studio compressors enabled control of compression ratio, attack and release times, and more. The Compressor Plus remains a simple ’70s-style stompbox squeezer at heart. But it has some very nice new options. The blend control is especially welcome. Players who use compression rely on the effect’s ability to even out note attacks and increase sustain, but there’s a downside: Note and chord attacks lose impact, and dynamic nuances can vanish. But with a wet/dry blend, you can have strong note attack and increased sustain.