SCA S90-500 Series Microphone Preamp Module
This is the 500 series module only! It will not work in any of the SCA chassis! There is an SCA only version of the S90 available as well in the Classic series section. The 500 Series kits require voltage measurement and calibration which can be easier with the use of a 500 series extender kit. We recommend this: https://www.diyrecordingequipment.com/products/500ext-500-series-extender-kit
The Seventh Circle Audio S90 is a transformerless microphone preamplifier that delivers the unmistakable character of the popular SSL 9000 consoles. Instead of the gain trim knob, the S90 features a switchable High-pass filter going from OFF-220 Hz using a 12 position Grayhill switch. Available as a DIY kit or fully assembled mic preamp module.
The S90 delivers up to 70dB of gain. This is more than enough gain for most applications, especially with modern high-output condenser microphones.
Stepped Gain Control
A 12 position Grayhill switch provides accurate and repeatable gain settings in about 5dB steps from 15dB to 70dB.
Inverts the signal phase.
Slow-rise phantom power minimizes pops and thumps.
Switchable from OFF-220 Hz using a 12 position Grayhill switch provides accurate and repeatable filter settings
High quality PC mount connectors eliminate cabling and ease assembly.
Polypropylene Coupling Capacitors
Instead of an input transformer, the S90 uses a combination of high-quality polypropylene film capacitors and bipolar electrolytic caps to block +48V phantom power while maintaining flat frequency response to below 10Hz.