AP215L

215L

API AUDIO

Designed for use with 200-series API Audio hardware such as the Legacy and Vision consoles and the L200 rack enclosure, the 215L is a high-pass/low-pass sweep filter module designed to cover a 20 Hz to 20 kHz range. With a 6 dB per octave low-pass filter and 12 dB per octave high-pass filter, the 215L makes it easy to shape frequencies while preserving natural tone.The 215L sports a passive filter design, which ensures a smooth tone with sculpting frequencies. The circuit features unity gain throughout and a transformer-balanced output set to +28 dBu. The module includes a hardwired bypass switch for silently disengaging the filter. With a fully discrete analog design that includes the reliable 2510 and 2520 op-amps, the 215L provides the signature sound API hardware is known for.Useful Studio Utility Because of the subtle nature of the 215L filter, it finds a home with uses like rolling off the low end of a hi-hat, where a natural sound is desired, not the usual phase-shifter sound of a 18 to 24 dB per octave filter found on most consoles. It can also be used to thin out room mics, without the complete loss of low end, which again, usually results from steep filter circuits.Isolated Filters The 215L design is a passive low-pass filter with a slope of only 6 dB per octave, and a passive dual high-pass filter with a slope of 12 dB per octave. The filters are isolated from each other with the same discrete transistor buffer used in the famous 550 series equalizers. This minimizes interaction between the filters as well as providing a low-impedance source for the filter following the buffer.Discrete Analog Circuitry The input section is a balanced circuit using the API 2510 all discrete op-amp, minimizing the loading effect on any device plugged into it. The output stage is a transformer balanced output, driven by the all discrete API 2520 op-amp.The 215L can be used in the Legacy, Legacy Plus, or Vision series consoles, or in the L200 Rack. The 215L filter makes use of the 2520 and 2510 op-amps and therefore exhibits the reliability, long life, and uniformity which are characteristic of API products.