Shure M61 free download

File name Shure-M61 preamp.pdf

DATA SHEET MODEL M61 SERIES TRANSISTOR STEREO PREAMPLIFIERS General: The Shure M61 Series Transistor Preamplifiers are designed to furnish the voltage gain and equalization necessary to operate magnetic phono cartridges (such as the Shure Dynetic Cartridges) and tape playback heads with standard audio amplifiers. One of the primary uses of the M61 is in conversion of Stereo systems from ceramic cartridges to magnetic cartridges. It can also be used without circuit modification as a preamplifier for microphones. Advantages include complete freedom from microphonics, extremely low noise, the use of 50 feet or more of output cable in "phono" and "tape" positions, and years of maintenance-tree performance. The operating temperature range is from 32°F. (0°C.) to 140°F. (60°C.). The Model M61-1 operates on 105-125 volts 50-60 Hertz power line. The Model M61-2 Hertz power line. operates on 210-240 volts 50-60 The Model M61-3 operates on battery power. The Model M61 Preamplifiers feature a single slide switch for selection of either phono (RIAA), tape (NAB), or a microphone (MIC) function. The RIAA position provides the Standard Equalization for phono records. The NAB position provides the Standard Equalization for tape and the MIC position provides a flat amplifier for microphones. The preamplifier has dual input and output jacks which will accept standard phono pugs. The input impedance is optimized for Dynetic and magnetic phono cartridges, for tape heads, and for low or medium impedance microphones. The output load will typically be the 500,000 ohm Tuner or Ceramic input of an Amplifier. Earphones of 4,000 ohms or more nominal impedance can be connected directly, or through a 1,000,000 ohm control, to the M61 output with the following specifications obtaining down to 250 Hertz or lower. Channel Balance: 2 db at 1,000 Hz. (for Phono end Tape functions) Hum and noise: 76 db below IO millivolt input, unweighted Distortion: Less than 1%. Measured at I volt output Output Clipping level: More than 4.5 volts (at 1,000 Hz.) Available power supplies: 1. 105-125 volts 50-60 Hertz (included in Model M61-1) 2. 210-240 volts 50-60 Hertz (included in Model M61-2. Available separately as Model PS220). 3. Battery [included in Model M61-3. Available Separately as Model PSB30). The battery (Burgess type K20 or Eveready type 430) provides 170 hours minimum of operation. SPECIFICATIONS Overall Dimensions: Gain: RIAA (Phono) 46 db (5 millivolts input produces 1.0 volt) NAB (Tape) 41 db (2 millivolts input produces 0.225 volt) MIC 63 db (2 millivolts input produces 2.8 volts) Preamplifier or power supply Length 5ј inches (133.4 mm) Width 2-7/16 inches (61.9 mm) preamplifier has plug pins extending en additional Ѕ inch (12.7 mm) Height 2-5/16 inches (58.7 mm) over switch button Net weight (M61-1) 1ј pounds (567g) Packaged weight (M61-1) 2Ѕ pounds (1133.8g) Frequency Response and equalization: Phono: Standard RIAA equalization Tape: Standard NAB equalization M