Conrad Johnson ART Phono MM & MC Tube Phono Preamplifier

The Conrad-Johnson ART Phono is very closely related to the ART88 in appearance, circuitry, and execution. Like the line stage unit, the phono stage is essentially a dual-mono unit with the two channels sharing only a power transformer and the chassis.

TRIODE GAIN STAGES
In the ART Phono, the circuit for each channel consists of two triode gain stages utilizing paralleled sections of 12AX7A twin-triode vacuum tubes coupled to the output through a buffer stage incorporating paralleled sections of a 12AU7/6189 twin-triode for low output impedance. Each channel is provided with two independent discrete regulated DC power supplies, one for the input gain stage, and one for the second gain stage and buffer stage.

The ART Phono is equipped with two phono inputs, one providing 53 dB of gain and featuring variable capacitive and resistive loading, and one available either with 47.5 kOhm fixed loading and 53 dB of gain, or optionally available with a step-up transformer for 63 dB of gain, with 46 Ohm load.

CJD TEFLON CAPACITORS
Conrad-Johnson proprietary CJD Teflon capacitors and Vishay metal foil resistors are used throughout the audio circuit and for the regulated plate voltage power supply. I/O connectors are machined from oxygen free copper, then silver plated with a Rhodium flash. The audio circuits are shock mounted on an independent daughter board and the casework is executed in heavy gauge aluminium to minimize microphonics.

Specifications
PHONO 1:
Gain 51db, load fixed 47K5 ohms
Gain 72db , load fixed 46 ohms
(with step-up transformers)
PHONO 2:
Gain 51db, load variable
147 Ohm to 47K5 Ohm
load variable 20pf to 956pf
Hum and Noise: <500uv
Phase: phase correct
Ouput Impedance: below 200 ohms
Mechanical
Dimensions: 16″D x 18.75″W x 5.44″H
Net Weight: 31 lb net