MV75 Vacuum Tube Power Amplifier

Introduced in 1979,

Introduced in 1979, the MV75 was conrad-johnson's second product, and first power amplifier. An immediate success, and widely acclaimed as a state-of-the-art contender, this power amplifier strongly signaled that conrad-johnson was indeed a serious company. Like the PV1, the MV75 employed metal film resistors and mylar capacitors throughout the circuitry.

The MV75 broke new ground in tube amplifier design by featuring a built in bias indicator circuit to simplify bias adjustment for the tube output stage-a task that must be performed whenever output tubes are changed, and periodically as they age. Earlier tube amplifiers required additional test equipment and technical expertise to set the bias for the output stage-a daunting task for many owners. The MV75 included a built in LED bias indicator for each output tube requiring only a screwdriver to accurately set the bias. This arrangement made it a simple matter for owners to keep their amplifiers operating at peak performance. All subsequent conrad-johnson tube amplifiers have included this built in bias indicator.

The MV75A upgrade added high-voltage fuses to protect the amplifier from shorted output tubes and upgraded the mylar capacitors to polypropylene. The MV75A-1 upgrade included circuit revisions to reduce the impedance of the regulated power supplies for the voltage amplifier and inverter stages.

Features: 4, 8, 16 ohm speaker taps (screw type), one pair of inputs, two plate fuses (MV75A, and MV75A-1), mono switch, power switch. Rack mount panel and tube cage were available as an option.

V1: 5751
V2 & V3: 6FQ7/6CG7
V4 V7: 6550
Replacement Tube Set RT75

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Stereo 75 watts per channel, RMS, at 4, 8, or16 ohms with both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD. Monaural 150 watts, RMS, at 4, 8, or 16 ohms from 30 Hz to 15 kHz, with no more than 1% THD or IMD.
Input Sensitivity: 2.35 Volts RMS to rated power
Frequency Response: 20Hz to more than 20kHz , +0, -.5dB
Hum & Noise: 94 dB below 75 watts
Dimensions: 15" X 10" x 9"
Weight: 43 lbs.