Krell K-300p Phono Preamplifier

Description

K-300p Phono Preamplifier

The K-300p is a high-performance phono preamplifier for
moving coil and moving magnet phono cartridges. With separate moving coil and
moving magnet inputs, the K-300p provides an optimal interface for each
cartridge type.

With adjustable resistive loading from 47k down to 10 ohms
and up to 62dB of gain (at 1kHz), the moving coil input can accommodate a wide
variety of cartridges, even low output models. The input is fed to a hybrid
discrete-IC circuit using paralleled low-noise transistors and a Burr-Brown
SoundPlus™ opamp. This creates the low-noise environment necessary for high
gain operation while taking advantage of the best audio features of each
section.

The moving magnet input runs into a dual low-noise FET
circuit that provides a highly stable input impedance of 47k ohms. With
adjustable capacitive loading from 0 to 680pF and gain up to 36dB it is well
matched to modern moving magnet cartridges.

The output from the moving coil or moving magnet sections
goes into a passive RIAA EQ network featuring precision resistors and
polypropylene film capacitors. This produces a highly accurate frequency
response that has only a +/-0.2dB deviation from ideal.

From there the signal goes into a balanced output stage
utilizing Krell CurrentMode topology. This circuitry has greater bandwidth than
traditional voltagemode designs for exceptionally transparent and effortless
sound quality.

The power supply utilizes a custom designed linear tracking
regulator that is extremely quiet and stable. This is important for high gain
circuits in order to reduce the overall noise level and ensure symmetrical
treatment of positive and negative signal excursions.

The K-300p is very easy to setup and operate. All the
loading and gain settings are accessible on the rear panel without the hassle
of opening the unit. Moving coil or moving magnet inputs are selectable
on-the-fly from the front panel.

There is also a default input switch on the rear panel so
the most commonly used input can be set to come up whenever the K-300p is
powered on. The absolute phase button on the faceplate can correct for
recordings that may be phase inverted. And the infrasonic filter button engages
a 14Hz critically damped high-pass filter that can eliminate low frequency
acoustic feedback problems.

The K-300p is packaged in an attractive black or
clear anodized aluminum and steel chassis that will fit on a standard rack
shelf.