The Stam SA-432 is a 1:1 replica of the iconic Sontec MES-432, a mastering equalizer first introduced in the mid-70s. This fully parametric stereo EQ, known for its precision and musicality, became a staple of mastering studios, shaping countless hit records from the 80s and 90s. With fully stepped switches and highly musical op-amps, it remains a go-to tool for mastering engineers worldwide.
At the heart of the Stam SA-432 are six reverse-engineered HS2030 and six HS6000 discrete op-amps, identical to those in the original Sontec. After two years of development, these op-amps were recreated to match the originals’ sonic characteristics while addressing stability issues. The updated design improves heat dissipation and longevity by leaving the op-amps unpotted. Running at +-28V for extended headroom, each op-amp is fully discrete, containing 13 transistors for optimal performance.
The circuit remains faithful to the original design, ensuring the Q and overall behaviour are identical to the original Sontec. Fully stepped switches with 1% tolerance resistors ensure perfect stereo matching and easy recall, with 0.5 dB increments for the first 3 dB, making it ideal for mastering.
The three parametric bands offer wide, overlapping frequency ranges for precise and musical tone shaping. The filter design uses a Bridged-T-filter in the feedback loop of an op-amp, and, as with the original, the filter section is bypassed in bypass mode, but the amp section remains active with the HS2030 op-amps.
For added versatility, a switchable mid-side matrix is available as an optional upgrade, catering to mastering engineers looking for advanced processing capabilities.
Each Stam SA-432 is built with superior components, including a UK-made toroidal transformer with a high-grade core, Panasonic capacitors for silent operation, 1% tolerance resistors, matched WIMA MPK and Polystyrene capacitors, and Neutrik XLR connectors. Period-correct knobs maintain the aesthetic of the original, ensuring the Stam SA-432 is as visually faithful as it is sonically accurate.
