Shure M67 4x1 mic/line mixer

All of the Shures in this section are in VG to VVG condition.   They were purchased new in 1982 and stayed in the same racks until their removal by bts.

If you're unfamiliar with the M67, these mixers are true workhorses, with simple, discrete transistor electronics and solid construction, they feature shielded transformer coupled inputs and outputs for very low noise and great headroom. 

The transformer isolated line output is capable of driving long lines with little loss.  This unit is great for doing drum kit submixes or where ever extra mic inputs are required.

All of these mixers have been relamped, cleaned up and fully tested.   They are in very good working order and will likely last another 25 years.

From Shure Literature:

The M67 is a transistorized microphone mixer/remote amplifier specifically designed for professional applications. The excellent performance and versatility of this complete, compact console make it an ideal choice for studio, remote, or original sound reinforcement use, and as an "add-on" mixer for expanding existing facilities. It is also ideally suited for use with tape recorders and VTR's to provide multiple microphone inputs.

PERFORMANCE
Frequency Response: 1-2 db from 30 to 20,000 Hz.
Gain: (Outputs terminated; line 600 ohms, rnicrophone 150 ohms). Gain will decrease a maximum of 5 db with nearly exhausted battery.
Input I (Line I 600Ω Low lmpedance Microphone 150 ohms) / -90 db 1- 30- db Line, Bridging or Terminating  140db 1 -20db
Noise: Equivalent input noise: -129 dbV (low impedance microphone, 150 ohms -300 to 20,000 Hz.) into 600-ohm load, at full gain.
Equivalent input hum and noise: -125 dbV (low impedance microphone, 150 ohms- 20-20,000 Hz.) into 600-ohm load, at full gain.
Distortion: Under 1% T.H.D. from 20 to 20,000 Hz. at + I 0 dbm out (0.5% Typical).

Features include:

• Wide, flat frequency response and low distortion at up to  +18 dbm output.
• Extremely low noise and RF susceptibility.
• Four low impedance balanced-line microphone inputs with individual gain controls.
• Mumetal shielding on input transformers.
• Line input switchable for 600-ohms terminating, or bridging.
• Outputs, 600-ohm line and low impedance microphone level. Outputs may be used simultaneously.
• VU meter calibrated for +4 and + I0 dbm with range switch. Illuminated with AC operation.
• Meter isolated from DC on line. Line output transformer unaffected by up to I00 ma DC.
• AC or battery operation (with accessory battery pack). Noiseless automatic switch-over to battery in event of AC line failure. Battery test provision.
• Low frequency roll-off switch on each channel.
• Two-level headphone monitor provision designed to accommodate 600 to 2,000 ohm headphones. Any headphones from 8 ohms to crystal may be used.
• Direct mix bus input for stacking units.
• Built in 700HZ Test tone oscillator
• Line output terminals phase indicated. All connections phased.

Control Interaction: Under 1% db with any control combination.

INPUTS
Mic Input Impedance 25 to 600Ω:   actual Input Clipping point -30 dbV (150 ohms) Greater than +22 dbV
Line Input: Bridging=10KΩ, Terminated =600 ohms  Greater than +24 dbm  (terminated)
Minimum Common Mode Rejection:  100 db with microphone input of I0 volts at I00 Hz.

OUTPUTS
Impedance
Output Designed For Actual Output Clipping
Use With (Internal) Level Microphone Any low 0.5 Ohms 6 rnv, - 4 4 dbV
Line impedance microphone
*Other line impedances may be used; however, the VU meter is calibrated for 600-Ohm line termination. See "VU Meter"

Temperature Range:
Operating: O°F to 135OF (-17.8OC to 57OC)
Storage: -20°F to 160°F ( -29OC to 71 O C )