VX-1
Stereo
Program
Equalizer
Operating Instructions
The Meyer Sound VX-1 is a two-channel program equal-
izer featuring three bands of minimum-phase boost or
cut equalization per channel. Optimized for composite
response shaping of stereo program material, the VX-1
utilizes a unique Virtual Crossover™ implementation,
with two frequency breakpoint controls and separate
gain controls for the Low, Mid and High bands.
The VX-1 occupies a single 1.75" standard rack
space, and the clearly marked controls include a
Master gain control, a single EQ In/Out switch and
a convenient Mono switch. Single-pole, minimum-
phase circuitry assures natural, graceful sonic
characteristics, even at extreme settings. The
dynamic range of the VX-1 exceeds 100 dB.
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
VX-1
Stereo
Program
Equalizer
Operating Instructions
0
dB
0
dB
0
dB
0
dB
0
dB
0
dB
0 dB
-3
-6
-3
-6
-3
-6
-3
-6
-3
-6
-3
-6
+2
+6
+3
+3
+3
+3
+3
+3
-3
240
4
k
240
4
k
+3
+4
+5
-6
320
6
k
320
6
k
Power
EQ
Mono
175
110
3
k
175
110
3
k
-12
+6
+6
+6
High
+6
+6
+6
High
-12
-12
-12
-12
-12
-12
490
9
k
490
9
k
Low
Mid
Channel A
2
k
Low
Mid
Channel B
2
k
-24
VX-1 Program Equalizer
-
∞
60
1
k
1
k
17
k
60
1
k
1
k
17
k
Gain
Figure 3. VX-1 Front Panel Controls
EQ In/Out Switch
The EQ In/Out Switch engages (in) or bypasses (out) the
VX-1 equalization stages. When the equalization is engaged,
the LED lights and the equalization controls are active.
When the equalization is bypassed, only the Master
Gain control and Mono switch are active.
Master Gain Control
The Master Gain Control regulates the gain of the VX-1. Its
range is from off to +6 dB, with 0 dB (unity) gain at the center
position.
Mono Switch
When the Mono Switch is engaged (in), the LED lights and
the two input channels are summed and routed to both out-
puts with equal amplitude. When the Mono switch is
disengaged (out), the VX-1 operates in stereo.
Signal/Clip Indicators
Equalization Controls
Centered directly under the equalization controls for each
channel, the Signal/Clip indicators will flicker green when
their corresponding channels are passing audio. The
indicators flash red to register signal clipping.
The VX-1 features a unique, Virtual Crossover™ implemen-
tation which is well suited for tailoring the broadband re-
sponse of program material. Operationally, it may be likened
to a conventional active loudspeaker crossover.
Mid and High bands. The gain controls affect the
relative amplitude (boost or cut) within each frequency
band, with a range of -12 to +6 dB.
The VX-1 equalization sections are first-order (6 dB/
octave) minimum-phase networks that provide gentle,
natural sonic characteristics. Figure 4 illustrates
typical response curves for various midrange control
settings.
Each channel of equalization incorporates five controls: two
frequency breakpoint controls, and three band gain controls.
The left-hand frequency control regulates the frequency
breakpoint between the Low and Mid bands, while the right-
hand frequency control regulates the breakpoint between the
+6.0
+3.0
0.0
-3.0
-6.0
-9.0
-12.0
20
100
1k
10k
20k
Frequency in Hz
Figure 4. VX-1 Response at Various Midrange Settings
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
VX-1
Stereo
Program
Equalizer
Operating Instructions
Frequency Response1
Specifications
Equalization In (Controls set flat)
Equalization Bypassed
20 – 20,000 Hz +0, -0.5 dB
20 – 20,000 Hz +0, -0.5 dB
Total Harmonic Distortion2
Hum and Noise3
Dynamic Range4
Inputs
< .005%
< – 90 dBV “A” Weighted
> 100 dB
XLR
Type
Balanced, transformer-isolated ISO™ Input5
16k ohms, 8k ohms per branch unbalanced6
+4 dBu, 16 dB headroom
Impedance
Nominal Input Level
Maximum Input Level7
+20 dBu
RCA
Type
Unbalanced active
8k ohms
Impedance
Nominal Input Level
Maximum Input Level
-10 dBV
0 dBV
Outputs
Type
Balanced active push-pull, pin 1 to chassis = 500ý
Impedance
300 ohms, 150 ohms per branch unbalanced
Nominal Output Level
Maximum Output Level
+4 dBu
+25 dBu
Controls & Indicators
Front Panel
Power
Locking pushbutton, red LED
Locking pushbutton, green LED
Locking pushbutton, yellow LED
31-position detented rotary controls
Rotary control
Notes:
EQ In/Out
Mono/Stereo
Frequency, Gain
Master
1. Measured at 0 dB gain
2. +18 dBV input, 1 kHz
3. Unbalanced
4. “A” weighted noise floor
to maximum RMS
output
Rear Panel
5. ISO™ input: Pins 1, 2
and 3 are transformer-
isolated. Shell is
connected to chassis/
AC mains ground. Pin
3 positive for positive-
going output at pin 3.
6. Pure resistive through-
out audio band
7. Within operating band
of each channel, this is
the minimum worst-
case level achieved
before clipping.
+4 dBu/-10 dBV select switch
Connectors
Recessed toggle
Balanced Input, Output
Unbalanced Input
3-pin XLR male, female
Gold-plated RCA female
Power
100/120/220/240 VAC, 50/60 Hz (switchable), 20W
Physical
Dimensions
Weight
19" W x 1.75" H x 7.5" D standard rack mount
8 1/4 lbs (3.75 kg)
8. 0 dBu ³ 0.775 vrms
0 dBV = 1 vrms
© 1991, Meyer Sound.
05.045.010.01 A
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
VX-1
Stereo
Program
Equalizer
Operating Instructions
Examples of Program
Equalization
The examples on this page illustrate typical response
characteristics obtained with various settings of the VX-1
band gain and frequency controls.
The control settings (Channel A only) used to obtain a
specific response are shown in the detail below the curve
plot.
50 Hz
20 kHz
Frequency
0
dB
0
dB
0
dB
0 dB
-3
-6
-3
-6
-3
-6
+2
+6
+3
+3
+3
-3
240
4
k
+3
+4
+5
-6
320
6
k
EQ
175
110
3
k
-12
+6
+6
+6
High
-12
-12
-12
490
9
k
Low
Mid
Channel A
2
k
-24
-
∞
60
1
k
1
k
17
k
Gain
Symmetrical High- and Low-Frequency Boost
50 Hz
20 kHz
Frequency
0
dB
0
dB
0
dB
0 dB
-3
-6
-3
-6
-3
-6
+2
+6
+3
+3
+3
-3
240
4
k
+3
-6
320
6
k
EQ
+4
+5
175
110
3
k
-12
+6
+6
+6
High
-12
-12
-12
490
9
k
Low
Mid
Channel A
2
k
-24
-
∞
60
1
k
1
k
17
k
Gain
Symmetrical High- and Low-Frequency Cut
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
VX-1
Stereo
Program
Equalizer
Operating Instructions
50 Hz
20 kHz
Frequency
0
dB
0
dB
0
dB
0 dB
-3
-6
-3
-6
-3
-6
+2
+6
+3
+3
+3
-3
240
4
k
+3
+4
+5
-6
320
6
k
EQ
175
110
3
k
-12
+6
+6
+6
High
-12
-12
-12
490
9
k
Low
Mid
Channel A
2
k
-24
-
∞
60
1
k
1
k
17
k
Gain
Gradual Downward Tilt
50 Hz
20 kHz
Frequency
0
dB
0
dB
0
dB
0 dB
-3
-6
-3
-6
-3
-6
+2
+6
+3
+3
+3
-3
240
4
k
+3
-6
320
6
k
EQ
+4
+5
175
110
3
k
-12
+6
+6
+6
High
-12
-12
-12
490
9
k
Low
Mid
Channel A
2
k
-24
-
∞
60
1
k
1
k
17
k
Gain
Gradual Upward Tilt
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
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