Conrad-Johnson PV12 preamplifier

Vaccum Tube Pre-amplifer

The PV12 draws on two decades of research at Conrad-Johnson into the reproduction of recorded music. The result is a line-stage preamplifier with a remarkable ability to recreate the dynamics, textures, tonalities, and ambience of live musical performances. With the PV12, we believe that you will experience the excitement of discovery in hearing more from your favorite recordings than ever before.

The audio circuit of the PV12 uses six vacuum tubes of three different types: two 12AX7 (V1 and V2), one 5751 (V3) and three 12AU7 (V4, V5 and V6).

Absolute Phase

Musical notes are heard through the ear’s response to waves of alternating rise and fall of air pressure. Musical ransients are almost exclusively positive: that is, the initial effect is a rise in pressure. The ear is capable of distinguishing these positive transients from the musically unnatural alternative of a negative transient (an initial fall in air pressure).

In terms of your stereo system, these transients are created by your loudspeakers. If the speakers respond to musical transients by first moving out, they are creating a rise in pressure, and the system is said to be "phase correct". If they respond by moving in, they create a fall in pressure and the system is said to be phase inverting. Each component

in the stereo system either preserves the phase of the incoming signal, and is said to be phase correct or inverts the phase and is said to be phase inverting. It is unimportant whether an individual component is phase correct or phase inverting, as long as the system as a whole is phase correct. This will be the case if the number of phase inversions is

even (or zero).

 

 

Specifications

Gain:

Phono Stage :  49 dB

Line Stage :  16.5 dB

Output: Maximum 20 V

Phase:  Line stage inverts phase of all inputs.

Phono Overload:  in excess of 200 mV at 1 kHz

Response:  bandpass 2 Hz to more than 100 KHz

RIAA Equalization to ±  .25dB (20 Hz - 20 KHz)

Hum and Noise (2 0Hz - 20 kHz):

Phono : 78 dB below 10 mV input

Line Level - 98 dB below 2.5V output

Distortion (Line Stage): THD & IMD less than .25%

Ouput Impedance: less than 800 Ω 

Dimensions (W x H x D):  19" x3,315" x  14.375"

Weight: 16 lbs