The Orban 674A is a dual-channel eight-band quasi-parametric equalizer of high professional quality, and is the stereo version of Orban's popular 672A equalizer. Because optimizing the controls for convenient stereo operation required placing corresponding "A" and "B" controls physically close to each other, there is slight crosstalk between the channels at very high frequencies (typically better than -55dB at 20kHz, falling at 6dB/octave at lower frequencies). A small amount of leakage from one channel to the other may be heard if you attempt to use each 674A channel to equalize entirely independent program material, and we recommend that the 674A be used only with stereophonic program material. If you require absolute isolation between the two channels, we recommend use of a pair of 672A equalizers instead. The 674A is equipped with graphic-type EQ controls providing up to l6dB of reciprocal boost or cut. The center frequency and bandwidth of each band are continuously variable to enable precise control of the audio spectrum. Wide-range high- and low-pass filters (12dB/octave) follow each EQ section for added versatility. When these filters are overlapped (200-2000Hz), the 674A can be used as a combined graphic/parametric equalizer and tunable electronic crossover. Separate lowpass and highpass outputs are provided for this purpose. Each channel of the 674A has an electronically-balanced bridging input, and unbalanced outputs (which can be balanced by the addition of optional output transformers). Input, outputs, and power line connections all contain effective RF filtering. l2dB of gain is available. AH potential overload points in the equalizer are monitored by an extremely fast "peak-stretching" overload detector, so that peak clipping can be detected and corrected before it becomes audible. The flexibility offered by the 674A makes it a particularly powerful tool in nearly all areas of audio: sound reinforcement, public address, recording studio, broadcasting, motion picture sound, dance bars (discos), theater..... The 674A easily meets the quality, performance, and reliability requirements of the demanding professional, and is also well-suited for use in semi-pro or audiophile applications. The controls and features of the 674A are fully described in this manual. It will familiarize you with the unit's potential and enable you to imaginatively use the 674A for your specific installation and application.