Phase Linear 4000 Autocorrelation
The 4000 Autocorrelation Preamplifier was a collaboration
design by Bob Carver and Bill Skinner. It was designed
to expand or uncompress the sonics of recorded material.
In audio parlance, it is called dynamic headroom. In the
midst of all the knobs and toggles is the four channel balance
The 4000 has the capability of controlling up to
six components: a tuner, two tape decks, two turntables and an
auxilliary. It has three switched and three unswitched
AC plugs. The 4000 was manufactured from 1973 to 1977.
It is still highly sought after today.
This unit is in good shape both functionally and
PL 4000 Features and contols:
Inputs: Phono1, Phono2, Aux, Tuner, Tape1, Tape2
Outputs: Front Main, Rear Main, Aux, Tape1, Tape2
Controls: Volume, Joystick 4 Channel Balance, Left & Right
Treble, Left & Right Bass, Unlimit Threshold, Correlation
Threshold, Peak Unlimit on Expand, SQ 4CH/2CH. Active Equalizer
In/Out, Stereo/Mono, Correlate In/Out, Tone Turnover Frquency
select 40/150/2K/8K Hz.
Phase Linear 400 Ampifiers
The 400 amplifier was, perhaps, Phase Linear's
most popular amplifier due to its more than adequate 200 watts
per channel and reasonable price tag. The 400 was introduced
in 1972 with a list price around $500.
PL 400 features:
Twin output VU meters.
8 output transistors per channel.
Factory rated frequency response of 5-250 KHz
200 Watts per channel.
There are 2 versions of the 400 before moving to
the 400 II model. This pair is the improved version of the 400
with the same additional heat sinking used in the 400 II model.
The 2 amps combined provide 4 channels at 200 Watts
each. Both amps work and sound excellent. One Amp has a small
scratch on the front face plate and the VU meter light is burnt
out (easily replaced). The other amp has a 1/4" hole in
the left most side of the faceplate where some chimp put a On/Off
toggle switch. Despite the hole, cosmetics are still good and
the VU meter light works.
All equipment is working. Enjoy!
The Pre-Amp Weighs about 18 lbs.
Each Amp weighs about 37 lbs.