CONRAD-JOHNSON PREMIER SEVEN TUBE PRE-AMPLIFIER

The Premier Seven was the first Zero-Feedback preamplifier from conrad-johnson.

It was a true dual-mono preamp design with a separate external regulated power supply for each channel. The result was a mammoth preamplifier, housed in four separate chassis.

Using 12 triodes (six per channel) in a zero feedback configuration provided extraordinary transient response not common in vacuum tube preamps. A low noise nuvistor input tube accommodated low output moving coil cartridges. A phono impedance selector was included for cartridge matching.

New standards of circuit components were used in the Premiere Seven, including 300 micron linear-crystal solid silver internal wiring. Each channel had its own level control. Instead of traditional potentiometers, the level controls are actually stepped attenuators which switch discrete pairs of precision resistors. Special laser trimmed metal foil resistors were used throughout the audio circuit.

The Premier Seven was stunning in its ability to resolve inner detail, recreate a huge dynamic range, and extended frequency response while presenting the soundstage with incomparable accuracy.

The Premier Seven-A offered a new phono stage circuit using a pair of nuvistors at the input. The resulting stage was even quieter, and capable of finer gradations in dynamics. The Premier Seven-B switched to machined oxygen free copper input/output jacks, upgraded internal wiring, and power supply resistors were upgraded to the same metal foil types used in the audio circuits.

Inputs/Outputs:

• 1 phono
• tuner
• auxiliary
• monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• two amplifier (main) outputs

Controls:

• source
• record
• level
• mute
• power

Premier Seven | Replacement Tube Set RTPREM7 (two channels)

each channel | V1: 6CW4 | V2-V6: 6GK5

Premier Seven-A, Seven-B | Replacement Tube Set RTPREM7A (two channels)

each channel | V1 & V2: 6CW4 | V3-V6: 6GK5

Specifications:

• Gain: Phono Stage 40 dB (phono overload 150 mV at 1kHz)
• Line Stage 29 dB
• Distortion: less than .25% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA equalization +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 80 dB below 10 mv input
• Line Stage 88 dB below 2.5 volt output

Mechanical:

• Dimensions (control unit) 19w | 7h | 16 3/8″d inches
• Dimensions (power supply) 19″w | 3.5″h | 16″d inches
• Weight: 60 lbs.