Studio Technologies 92 User Manual

User Guide

Issue 3

This User Guide is applicable for serial numbers:

AN2-00251 and later

© 1998 Studio Technologies, Inc.

5520 West Touhy Avenue

Skokie, Illinois 60077 U.S.A.

Telephone [phone]

Fax [phone]

www.studio-tech.com

50011, Issue 3

Table of Contents

Introduction.................................................................................. 5

Installation.................................................................................... 6

Operation..................................................................................... 7

Theory of Operation and Troubleshooting...................................1 0

Specifications...............................................................................13

Studio Technologies Limited Warranty........................................14

Figure 2 .........................................................Not included in PDF

Figure 3 .........................................................Not included in PDF

Schematic Diagrams ........................................Not included in PDF

AN-2 User Guide Issue 3
Studio Technologies, Inc. Page 3

Introduction

The Studio Technologies AN-2 Stereo
Simulator has numerous applications within
recording, live performance, film and broad­cast operations because of its ability to
create a simulated stereo signal from a
monophonic source. The AN-2 is also
capable of a number of audio effects cen­tering on its ability to simulate stereo. The
stereo signal produced by the AN-2 is
completely mono compatible, so that it can
be remixed back to mono without the seri­ous signal degradation often encountered
when remixing simulated stereo produced
by other equipment such as delay lines and
harmonizers. In addition, the AN-2 is
equipped with a proprietary circuit that
randomizes the non-reclusive filtering pro­cess, thereby avoiding the harmonic harsh­ness that often results from stereo
simulation with delay lines.

Operational Description

To understand the operation of the AN-2,
it is useful to have a basic understanding
of the way stereo recording techniques can
fool the brain into believing it is hearing a
number of sound sources.

When two or more microphones are used
to record music, two effects are noticed
when the recording is played back over
two speakers. They are:

• Directional effects: These are due to
differences in arrival times at the ears and
the intensity differences of the various
frequencies that make up the music.

• Spaciousness imparted to the sound:
The sound is perceived as originating
from an area that is wider than the room
in which the listener is sitting. This
spaciousness is caused by the interaction
of the sounds that reach the microphones
directly and those sounds that reach the
microphones after being reflected from
the surfaces of the recording studio.

The degree of spaciousness of the re­corded music coming from the two
speakers is dependent on the amount of
coherence (sameness or consistency)
between the signals fed to the speakers.

If the two channels are perfectly coherent
(the same signal fed to both speakers), the
sound heard is monaural and the source
of the sound seems to be midway between
the two speakers. As the signal fed to one
speaker begins to vary from the signal fed
to the other, the channels become incoher­ent and the spaciousness of the sound
increases. This effect is known as “imag­ing,” and results in the impression that each
instrument or voice is coming from a differ­ent point in space. The definition and clarity
of the sound sources seems to increase as
the imaging increases, up until the point
where the two channels become completely
incoherent, or different. At this point, the
stereo image collapses and there is no
spacial effect at all. What is heard, rather,
are two mono channels.

The AN-2 is designed to allow you to vary
the degree of coherence of the sound (and
the resultant amount of imaging) using the
depth and width controls, creating a simu­lated stereo signal from a monophonic
source. The two output signals of the AN-2
can be recombined, restoring mono.

AN-2 User Guide Issue 3
Studio Technologies, Inc. Page 5

Mono Compatibility

In many applications, especially recording
and broadcast, it is critical that any stereo
signal produced can be summed (L+R)
without adverse effects. The AN-2 was
designed so that the simulated stereo signal
produced is completely mono compatible.
No setting of the controls or circuit anoma­lies ever produce a problem in this area.

The AN-2 uses the classical technique of
creating comb filters, as shown in Figure 1.
The transfer function of the upper network
is H(z) = 1 – z
2/T, 3/T, etc. The lower network is merely
the complement of the upper; where the
upper network has an amplitude peak, the
lower has an amplitude dip. If the two out­puts are summed, it can easily be seen that
the delay line is cancelled out, leaving only
the direct, or mono, unaltered signal.

Figure 1

For musical reasons, the AN-2 uses a
network after the delay line to randomize
the peaks and dips. However, the peaks
and dips are still interleaved and the mono
sum is also the same as the input signal.

–n

, resulting in dips at 1/T,

Installation

The AN-2 is rack-mountable, requiring one

1.75-inch (4.45cm) rack space. It weighs
five pounds (2.27kg), and operates on
either 115Vac or 230Vac. Refer to the
Specifications section for more complete
electrical and physical specifications.

Placement

If you wish to mount your AN-2 near other
equipment, make certain that it is not near
the power transformer of another unit. The
AN-2 is well shielded, but some of the
circuitry is sensitive to high levels of EMF
from outside sources.

Connecting the Unit to Power

The AN-2 may be operated from either
100-125 or 200-250Vac power, 50/60Hz.
Units shipped to North America are factory
selected for 115V operation and are sup­plied with a 0.5A 3AG fuse. Units shipped
outside North America are factory selected
for 230V operation and supplied with a

0.25A 5 x 20mm fuse. Before connecting
the AN-2 to power, determine the actual line
voltage and check to see that the voltage
selector switch (located on the back panel
of the unit) is set to the appropriate voltage.
Please note that an incorrect setting could
seriously damage the unit. Should it be
necessary to change the voltage selection,
insure that the correct fuse value is used:

0.5A for 115V, 0.25A for 230V.
The AN-2 utilizes an IEC standard connec-

tor to mate with the line cord. The line
cord supplied has a North American stan­dard plug at one end and an IEC connector
at the other. In non-North American app­lications the plug must be cut off and an

Issue 3 AN-2 User Guide
Page 6 Studio Technologies, Inc.