Phase Linear 1000 Owners manual

Phase Linear Model 1000
Autocorrelator Noise Reduction System

You have just purchased the most advanced and most versatile noise reduction and dynamic
range recovery system available. Proper use of your Phase Linear 1000 will allow you to
reproduce music with less noise and greater dynamic range than previously thought possible. We
hope you will read this manual thoroughly in order to appreciate all the benefits of the 1000.

Recording studios and record processing companies employ a number of "necessarily evil”
techniques brought about by the state of the recording art. Taken together, these techniques may
be described as processes which serve to limit and restrict the dynamic range of recorded
material. Unfortunately, their use is necessary in order to put the tremendous dynamic range of
live music onto the surface of modern phonograph discs and tapes. When used properly, the
Phase Linear 1000 will significantly correct these shortcomings inherent in the recording process.

Before leaving our factory your Phase Linear 1000 was tested and certified to be in perfect
operating condition. This manual has been prepared to help you operate your Phase Linear as
well as keep it in perfect condition. Your Phase Linear when used with care befitting all fine
instruments, is capable of truly providing a lifetime of musical fulfillment.

CONNECTIONS

1. Check front panel to insure:
a. The power switch is in the off position.
b. The 1000’s tape switch is in the source position (out).

2. Connect tape output on your receiver (preamp) to the input on the 1000 and connect the
1000’s outputs to your receiver’s (preamp) tape input jacks.

3. Plug in the 1000’s AC cord while leaving the unit turned off.

4. Turn on your receiver (preamp), and then turn on the 1000.

5. The tape monitor on your receiver or preamp should be in the monitor position.

6. Refer to the Operating Instructions for correct operation and adjustment of the Correlator and
Peak Unlimiter circuits.

AUXILIARY EQUIPMENT
Outboard units such as Dolby or DBX may be used with your 1000 but the 1000 must be placed

“after” the units in the signal path and “before” any equalizer in signal path, or as shown.

Any source played through the 1000 will be processed. It is not necessary, therefore, to process
a signal prior to recording since it will be processed on playback. However, if you wish to make a
tape to be played back on another system, simply install the 1000 between source and the tape
recorder.

Note: It is not advisable to use the Expander during recording since it will stress the recorder’s
dynamic range capability.

FRONT PANEL CONTROLS

Unlimit Threshold Lamp: Provides visual indication of peak unlimit operation. This lamp should

come on during the peaks in the program material but should not stay on all the time.
Unlimit Threshold: Rotate clockwise to increase dynamic range of program material. Adjust so

that unlimit indicator lamp illuminates on peaks and extinguishes between musical peaks. This
knob adjusts both the peak unlimiter and the downward expander.

Low Frequency Calibration: Adjusts low frequency noise reduction. Once this is adjusted
properly it should not be changed unless your cartridge or turntable is changed. An incorrect
setting of this control will cause a loss of bass response. (See Operating Instructions)

Correlation Threshold: Rotate counterclockwise to remove noise from program material.
Correct adjustment is indicated by absence of random hiss and presence of all high frequencies

associated with the musical program. Incorrect adjustment is indicated by complete loss of high
frequencies or by presence of noise in the program. Typically, proper settings are found in the
eleven to three o’clock positions though this setting will vary with the source material.

Power Indicator: Illuminates when unit is on.
Power: Press in to turn unit on.

Autocorrelator: Press in to activate correlator.
Peak Unlimiter: Push in to activate Peak Unlimiter/Downward Expander.
Tape Source: Press in to use tape path on Model 1000.

OPERATING INSTRUCTIONS

AUTOCORRELATOR

The AUTOCORRELATOR is a noise reduction system designed to remove noise from any
signal source. The following steps should be used to adjust the AUTOCORRELATOR:

Step 1: Rotate the CORRELATION THRESHOLD control fully clockwise.
Step 2: Check to insure that the Correlator is turned on.
Step 3: Put on a good quality record, advance the treble controls to full maximum on your

preamplifier or receiver. Select a portion of the record in which hiss may readily be heard
against the musical program. Slowly rotate the Correlation Threshold counterclockwise. As the
control is progressively rotated counterclockwise, a point will be reached at which the record
hiss drops to a very reduced level while the high frequencies of the musical program remain
unaffected. Further counterclockwise rotation will have no effect on the program until a rather
extreme counterclockwise rotation results in an abrupt and complete loss of high frequencies
associated with the music. The Correlator is said to be "in lock” when the threshold control is
set anywhere within the two limits outlined above. The correct setting is midway between these