Moog Music MF-104Z User Manual

Understanding and Using Your

moogerfooger®

MF-104Z ANALOG DELAY

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Welcome to the world of moogerfooger® Analog Effects Modules.
Your Model MF-104Z Analog Delay is a rugged, professional-quality
instrument, designed to be equally at home on stage or in the studio.
Its great sound and smooth player controls come from its state-of-the­art analog circuitry, designed and built under Bob Moog's personal
direction.

Your MF-104ZAnalog Delay features an all-analog delay circuit
with delay times from 50 milliseconds to 1000 milliseconds. Its finely
tuned frequency response and overload contours produce the sound
quality of the best classic vintage delay devices. Each of the three
performance parameters may be controlled smoothly and
continuously by panel knob, expression pedal, or external control
voltage. Audio input and output signals may be set to any instrument
or line level. Housed in a rugged steel and hardwood enclosure, the
MF-104Z, like other moogerfooger instruments, has the classic good
looks, versatility, and high sound quality of the well-known vintage
MOOG synthesizers.

The following pages will first tell you how to hook up your MF­104Z and set the panel controls for the ‘basic’ setup. Next, we'll explain
how your MF-104Z works. After that we'll go through the panel
features and give you suggestions on how to use your MF-104Z in
some specific applications. At the end of this booklet, you'll find
technical specifications, service, and warranty information, and
information about Moog Music.

CONTENTS

GETTING STARTED - - - - - - - - - - - - - - - - - - 3
WHAT IS AN ANALOG DELAY? - - - - - - - - - - - - 6
PERFORMANCE PARAMETER CONTROLS - - - - - - 7
THE WHITE SWITCHES - - - - - - - - - - - - - - - - - 8
THE AUDIO LEVEL CONTROLS - - - - - - - - - - - - 9
AUDIO OUTPUTS; EXPRESSION PEDALS - - - - - - - 11
TYPICAL SETUPS - - - - - - - - - - - - - - - - - - —- 12
TECHNICAL INFORMATION - - - - - - - - - - - - - 17
WARRANTY INFORMATION - - - - - - - - - - - - - 21

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SPECIFICATIONS - - - - - - - - - - - - - - - - - - - 22

GETTING STARTED

Here are simple instructions on how you can quickly plug in and
try out your MF-104Z.

1. Unpack your MF-104Z. You can place it on a table or on a floor. We
suggest that you place it on a table while you become familiar with its
features.

2. Check that the power adapter has a nominal rating of +9 volts and
is also rated at your country's standard power voltage (120 volts A.C.
for the United States and Canada, 100 volts A.C. for Japan, and 220
volts A.C. for most other countries). Plug the power adapter's cord
into the MF-104SD's `+9V' jack. Then plug the power adapter itself
into a power voltage receptacle. (See Page 19 for more detailed
technical information on power adapters for the MF-104Z.)

3. Note that the BYPASS light is on. It will light up either red or
green. Red indicates that
the MF-104Z’s delay
circuit is off-line
(bypassed), while the
green indicates that the
delay circuit is on-line.
Pressing the `stomp
switch' will toggle the
BYPASS light between
red and green. For now,
leave the BYPASS light
on red.

Refer to Figure 1 for steps 4.
and 5.

4. Connect an instrument
cable from the MIX OUT
jack to a line-level input
on your amp or mixer.

Figure 1 - Basic connections: Instrument to
AUDIO IN, monitor amp to MIX OUT, and
power adapter to +9V.

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Turn the volume control on your amp down but not off.

5. Connect an instrument cable from your signal source to the AUDIO
IN jack. You can feed virtually any instrument-level or line-level
signal through your MF-104Z. Examples are guitar, bass, keyboard,
theremin, drum machine, or Effects Send output on your mixer.

Refer to Figure 2 for step 6.

6. Set the MF-104Z panel controls as follows.

MIX 0
DELAY TIME 0.3
FEEDBACK 0
LOOP GAIN 0
DRIVE fully

counterclockwise
OUTPUT LEVEL fully

counterclockwise
Left Switch SHORT
Right Switch INT. LOOP

Play your instrument (or turn on
the signal source). Adjust the
volume control on your monitor
amp so that the sound level is
comfortable.

Now set the DRIVE and OUTPUT
LEVEL controls exactly as
described in steps 7. and 8.

Figure 2 - Basic settings for becoming
familiar with your MF -104Z.

7. Press the stomp switch so the
BYPASS light goes green. Playing your instrument, set the DRIVE
control so the INPUT LEVEL indicator lights up green-yellow or red­yellow most of the time, and becomes bright red only on occasional
peaks.

8. Set the OUTPUT LEVEL control so that there is no loudness change
when the BYPASS light goes back and forth between green and red.

Once the DRIVE and OUTPUT LEVEL controls are set, you should not
change them unless you change the loudness of your signal source.

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9. Switch the BYPASS light to green. Continuing to play your
instrument, turn the MIX control clockwise. When the MIX control is
at 0, you will hear just the direct (undelayed) signal. When the MIX
control is at 5 (midposition), you will hear both the direct and
delayed signal. When the MIX control is at 10, you will hear just the
delayed signal. Note that the delayed signal has a softer, more muted
quality than the direct signal, - just as natural echoes are softer and
more muted than direct sounds.

10. Set the MIX control to 5, so you hear both the direct and delayed
signals. Vary the setting of the DELAY TIME control. When the
control is fully counterclockwise, the delay is very short, - about 50
milliseconds. (A millisecond is a thousandth of a second.) When the
control is fully clockwise, the delay is about 500 milliseconds. Note
that when you turn the DELAY TIME control while you're playing,
the pitch will change briefly. This is because turning the DELAY
TIME control causes your sound to stretch or compress as it goes
through the delay circuit, thereby speeding up or slowing down the
vibrations.

11. Set the left switch to LONG. This doubles the delay time. It also
imparts an even more muted quality to the delayed signal.
Experiment with various settings of the DELAY TIME control and the
SHORT-LONG switch to get a feeling for how they affect the delayed
signal.

12. Return the left switch to SHORT and the DELAY TIME control to
midposition. Turn the FEEDBACK control slowly clockwise. You will
now hear a series of echoes of each sound that you play. The
FEEDBACK control creates the series of echoes by mixing a portion
of the delayed signal with the signal from your instrument. When the
FEEDBACK control is set to about 8, the echoes sustain indefinitely.
With the FEEDBACK control above 8, the echoes build up chaotically
into some amazing electronic textures.

In the next sections we'll explain how an analog delay works and
look at your MF-104Z in more detail. For now, get a feel for your MF­104Z's controls by experimenting with different settings.

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WHAT IS AN ANALOG DELAY?

A delay circuit produces a replica of an audio signal a short time after
the original signal is received. If you listen to the original (direct)
signal and the delayed signal together, the delayed signal will sound
like an echo of the direct. To make a whole series of echoes that die
out gradually, you feed the delayed output signal back to the input.
You can determine how far apart the echoes are by adjusting the
delay time of the delay circuit, and you can adjust how fast the
echoes die out by adjusting the amount of feedback from the delay
circuit output to its input. In addition, you can determine how loud
the echoes are by adjusting the mix between the direct signal and the
delayed signal.

Today there are three types of delay devices: tape, analog, and
digital. The first delay devices used magnetic tape to create the delay.
The sound was recorded on a moving tape, and then played back
after the tape had moved a few inches or so. Then, during the early
`70's, large-scale semiconductor analog delay circuits became
available. These were called bucket brigade delay chips, because they
functioned by passing the audio waveform down a chain of several
thousand circuit cells, in analogy to water being passed by a bucket
brigade to put out a fire. Each cell in the chip introduces a tiny delay.
The total time delay depends on the number of cells and on how fast
the waveform is `clocked', or moved from one cell to the next. Analog
delays were less noisy, easier to use, and more reliable than tape echo
units, and came to be more widely used.

More recently, digital delay units have come into use. In a digital
delay unit, the sound signal is first converted to numbers. The
numbers are stored in a digital memory for a certain time, and then
retrieved and reconstructed into the delayed audio waveform. One
significant difference between analog and digital delay units is that
the particular frequency and overload contours of well-designed
analog devices generally provide smoother, more natural series of
echoes than digital delay units. Another difference is that the echoes
of a digital delay are static because they are the same sound repeated
over and over, whereas a bucket brigade device itself imparts a
warm, organically evolving timbre to the echoes.

The design of your MF-104Z Analog Delay is unique because it
combines authentic, finely-tuned vintage analog bucket-brigade
delay circuitry with analog-synthesizer-style voltage control of delay
time, feedback, and direct/delay mix.

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PERFORMANCE PARAMETER CONTROLS

Performance parameters are controls that are meant to be played
during performance. Each of the MF-104Z's performance parameters
is controlled both by a front panel knob and by a pedal/control jack
on the rear panel. The parameters are MIX, DELAY TIME, and
FEEDBACK..

MIX control: As you turn the MIX knob clockwise from 0 to 5, the
delayed signal becomes louder while the direct signal remains at
maximum volume. Then, as you turn the MIX knob from 5 to 10, the
delayed signal remains at maximum volume while the direct signal
decreases to silence. This characteristic gives a natural-sounding mix
for most music signals.

If you're applying a sustained steady pitch to the MF-104Z and the
MIX control is set near midposition, you may find that the direct and
delayed signals alternately reinforce and cancel each other in rapid
succession as the delay time is varied. This is a normal result of
mixing a steady pitch with a delayed replica of itself. It is the analog­delay equivalent of `standing waves' in a reverberant room.

DELAY TIME control: With the

SHORT/LONG switch set on
SHORT, the delay time will vary

from 50 milliseconds to 500
milliseconds as the DELAY TIME
knob is turned clockwise. Note that
the knob is calibrated directly in
time (seconds).

With the SHORT/LONG switch set
on LONG, the DELAY TIME knob
will vary the delay time from 100
milliseconds to 1000 milliseconds.

FEEDBACK control: There is no
feedback when the FEEDBACK
knob is on 0. The feedback increases
as you turn the knob clockwise.
When the knob is around 8, the
echoes will sustain indefinitely for

Figure 3 - MF -104Z Front Panel.

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most delay time settings. With the FEEDBACK knob turned
clockwise past 8, the echoes will grow in amplitude until they reach
the overload point of the delay circuitry. In addition, the background
noise will also build up and compete with the delayed signal.

When you switch your MF-104Z into BYPASS, the feedback loop will
shut down and the echo stream will die out within less than a second.
Then, when you switch your MF-104Z on again, a new echo stream
will begin to build up. This is a convenient way of `canceling' an echo
stream while you're playing.

The SHORT-LONG switch works with the DELAY TIME control.
The delay time range is 50 milliseconds to 500milliseconds when the
switch is on SHORT, and 100 to 1000 milliseconds when the switch is
on LONG. In addition, the frequency response of the delay circuit is
more restricted when the switch is on LONG than it is when the
switch is on SHORT.

The INT.LOOP-EXT.LOOP switch selects the feedback path.
When this switch is in INT.LOOP, the feedback path goes directly
from the output of the delay circuit back to the input. When this
switch is in EXT.LOOP, the feedback loop goes through the LOOP
OUT jack and the LOOP IN jack. This provides you with an
opportunity to insert a signal processor of your choice in the feedback
path, thereby enabling you to process the echoes as they're being
generated. The LOOP GAIN knob affects only the external loop, and
has no effect whatsoever when the switch is set on INT.LOOP.
Detailed information on using the external loop and setting the LOOP
GAIN knob is given in the next two sections.

THE WHITE SWITCHES

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