CLOUD VMA240, VMA120 VMA_Series_Datasheet_EN_v1.1.pdf

VMA CONTRACTOR SERIES MIXER-AMPLIFIERS

MODELS: VMA120, VMA240

General Description

The Cloud VMA120 and VMA240 are cost-effective mixer-ampliers

for use in all types of commercial premises. They have been
designed to be as simple to install and operate as possible, but offer

a useful range of features and conguration options.

The units are mono power ampliers combined with a simple

mixer stage. The two models are identical in terms of facilities, and
differ only in the maximum power output available – 120 W or 240
W respectively. They may be used to drive either low-impedance
loudspeakers directly (4 ohms minimum) or
25/70/100 V-line loudspeaker distribution systems. The two different
types of speaker system cannot be driven simultaneously. A high-

pass lter, selectable by internal jumper, minimises the effect of

transformer saturation at low frequencies when driving 25/70/100
V-line systems.

The units have four stereo line inputs (typically for connection of
music sources), including an AUX input in the form of a 3.5 mm

jack socket on the front panel to permit the easy connection of

laptops, tablets and similar devices. Two balanced microphone
inputs are also provided: phantom power is available at each,

selectable by internal jumper. A high-pass lter for each mic input
may also be selected by internal jumper: this reduces the effects

of handling and breath noise. All mic and line inputs (except the

AUX input) have a preset-type gain control adjacent to the input

connectors on the rear panel.

The front panel has rotary controls for line input selection, music

level, the level of each mic input, and LF/HF EQ adjustment for

the summed mic inputs. Two switches enable priority options: one
allows the mic inputs to have priority over music sources to permit
announcements, the other gives one line input priority over all

others: this is useful for connecting a jukebox or message store, for

example. Two further switches enable/disable each mic input. The
front panel controls also include a master level control and HF/LF

EQ adjustment for the main output.

VMA120 illustrated: Model VMA240 is identical

The rear panel has a music mute control input which can be used

to mute all music sources in an emergency: an internal jumper

allows this to also mute the mic inputs if wished. There is also a

balanced auxiliary output to allow additional power ampliers to be

slaved.

VMA Series: main features:

• Industrial quality mixer-ampliers

• Power output: 120 W/channel (VMA120) or 240 W/channel
(VMA240)

• Outputs suitable for either low-impedance (min. 4 ohm) or
25/70/100 V-line systems

• Four stereo unbalanced line inputs (3 x RCA jack pairs,

1 x 3.5 mm TRS jack on front panel)

• Rear panel line inputs have individual gain controls

• Two balanced mic inputs (1 x multipin connector, 1 x ¼” TRS

jack), with individual preset gain controls

• Front panel controls for mic and music levels, line input
selection, mic EQ, master level and EQ

• Mic input mute switches on front panel

• Line 1 priority, enabled by front panel switch

• Mic-over-music priority, enabled by front panel switch

• 15 V phantom power available at either mic input (selected by

internal jumper)

• 100 Hz high-pass lter on each mic input (selected by internal
jumper)

• 70 Hz high-pass lter in output stage, for use with
25/70/100 V-line systems

• Fixed limiter – prevents clipping

• Front panel LED bargraph – indicates output signal level

• Over-temperature and output DC protection

• 230 V or 115 V operation

• Forced-air cooling

Block Diagram

0V

8Ω

RED

BLK

(OPTIONAL)LOW-Z OUTPUT

100V

70V

25V

0V

BLK

RED

(FACTORY) HI-Z OUTPUT

120W

LIMITER

-

+

ZONE AUX OUT

DISCONNECT RED/WHITE 2-WIRE MATING CONNECTOR

TO CABLE TO OUTPUTS FOR LOW IMPEDANCE OUTPUTS

FROM AMPLIFIER MODULE TO TRANSFORMER, THEN REFIT

PRI

LINE 1

MUTE

MUSIC

LINE 1

DETECT

PRIORITY

J100

HIGH PASS

LEVEL

MASTER

MUTE

MIC

DUCKING

70 Hz

EQ

MASTER

MIC

MIC

PRI

DETECT

PRIORITY

J203

LEVEL

100 Hz

MIC

J201

JP1

APPLY MUTE

EQ

TO MICS

MUTE

LEVEL

100 Hz

FILTER

J201/J203

HIGH PASS

MICROPHONE

J1 PRIORITY

TRIGGER PRE/POST

GAIN

LINE 1

SOURCE

LINE 2

SELECTION

GAIN

LINE 3

GAIN

AUX IN

GAIN

J205

J202

++

MIC 1

J204

J200

++

MIC 2

GAIN

TRIGGER

PRIORITY

J204/J205

PRE/POST

+15V

POWER

J202/J200

PHANTOM

Technical Specications

Line Inputs

Frequency Response 20 Hz to 20 kHz, ±1 dB
Gain range 0 dBu to +20 dBu
Input impedance 47 kohms
Noise <-82 dB (22 kHz bandwidth)
Equalisation LF: ±10 dB @ 50 Hz HF: ±10 dB @ 10 kHz

Microphone Inputs

Frequency Response -3 dB @100 Hz (xed lter) to 20 kHz, ±1 dB
Gain range 2.45 mV (-50dBu) to 245 mV (-10 dBu)
Input Impedance 3.3 kohms (balanced)
Phantom Power 15 V, switchable per-input by jumpers
Noise (EIN) -125 dBu (20 Hz to 22 kHz bandwidth, max gain, Rs = 150 ohms)
Equalisation LF: ±10 dB @ 100 Hz; HF: ±10 dB @ 5 kHz

Main Output

Output Power
(1 kHz continuous sine wave)

Minimum load

Frequency response

THD + N < 0.08% @ 1 kHz
Protection Fixed level signal limiter: DC and over-temperature protection

Auxiliary Output

Nominal output level 0 dBu (0.775 Vrms), balanced
Noise <-82 dB, 22 kHz bandwidth

General

Power input Selectable 115 VAC or 230 VAC, ±10%; 45 – 65 Hz

Fuse details 5 x 20 mm, time delay

Normal operating temperature

Cooling Forced air cooling, 80 mm dia. fan; airow front-to-back

Power Consumption

Heat Loss

Dimensions (W x H x D)

Weights

VMA120 120 watts
VMA240 240 watts
Low-Z output 4 ohms

VMA120 5.2 ohms
VMA240 2.6 ohms
VMA120 41 ohms
VMA240 20 ohms
VMA120 83 ohms
VMA240 41 ohms

High-Z output

25 V-line

70 V-line

100 V-line

Low-Z output 20 Hz to 20 kHz, ±1 dB
High-Z output 20 Hz to 20 kHz, ±1 dB (70 Hz lter off)

230 V models 2 A
115 V models 4 A

0 °C to 35 °C

(Note: performance and specications cannot be guaranteed outside of this range)

2

Idle

1/8th Power

1/3rd Power

Idle

1/8th Power

1/3rd Power

3

4

2

3

4

Net

Shipping (Gross)

Net

Shipping (Gross)

VMA120 13.5 W (19.2 VA)
VMA240 15.5 W (20.5 VA)
VMA120 88.6 W (119.7 VA)
VMA240 188.5 W (251.3 VA)
VMA120 136.5 W (177.7 W)
VMA240 252.1 W (330 VA)
VMA120 48.7 KJ/hr (46.1 BTU/hr)
VMA240 55.8 KJ/hr (52.9 BTU/hr)
VMA120 276 KJ/hr (262 BTU/hr)
VMA240 548 KJ/hr (519 BTU/hr)
VMA120 407 KJ/hr (386 BTU/hr)
VMA240 665 KJ/hr (630 BTU/hr)

482.6 mm x 88 mm (2U) x 267 mm
19” x 3.5” (2U) x 10.5”

535 mm x 185 mm x 350 mm

21.1” x 7.3” x 13.8”
VMA120 7.9 kg / 17.7 lbs
VMA240 9.6 kg (22.2 lbs)
VMA120 8.7 kg / 19.5 lbs
VMA240 10.5 kg (23.5 lbs)

Notes re Power Consumption and Heat Loss measurements:

All measurements at 230 VAC 50 Hz power input

1. Idle: amplier active, but no audio output

2. 1/8th. Power: constant sound level at one-eighth maximum rated output per channel (audio mainly clean, only occasional clipping)

3. 1/3rd. Power: constant sound level at one-third maximum rated output per channel (audio beginning to become compressed, limited or heavily clipped)

Dimensions

88 mm

482.6 mm

263.5 mm

SIDE VIEW

427 mm

87 mm

Performance Graphs

+14

+12

+10

+8

+6

+4

+2

d
B
r

-0

A

-2

-4

-6

-8

-10

-12

-14

20 20k50 100 200 500 1k 2k 5k 10k

Hz

+20

+15

+10

+5

+0

-5

d

B

r

-10

A

-15

-20

-25

-30

-35

-40
20

50 100 200 500 1k 2k 5k

65 Hz lter ON

20k

10k

4.8

4.6

4.4

4.2

3.8

3.6

3.4

3.2

2.8

2.6

%

2.4

2.2

1.8

1.6

1.4

1.2

0.8

0.6

0.4

0.2

Main EQ

5

4

3

2

1

20

THD + Noise

Frequency response

+10

+7.5

+5

+2.5

+0

-2.5

-5

-7.5

-10

-12.5

d

-15

B

-17.5

r

-20

A

-22.5

-25

-27.5

-30

-32.5

-35

-37.5

-40

-42.5

-45

-47.5

100 200

50

1k

500

Hz

2k 5k 10k

20k

20

100 200

50

1k 2k 5k 10k

500

Hz

20k

Mic frequency response

Architect’s and Engineer’s Specication

The mono mixer-amplier shall be equipped with four unbalanced

stereo music inputs: three of these shall be on phono sockets

(RCA jacks) and one on a 3.5 mm 3-pole jack socket which shall
be accessible from the front of the unit. The mixer-amplier shall

have two balanced microphone inputs on detachable multipin
connectors. The music input to be used shall be selected by a
four-position front panel rotary switch. The two mic inputs shall be
mixed to a mono signal and summed with a mono (L+R) sum of the
selected music input. Each mic input shall have its own front panel
level control. It shall be possible to control the level of the music
source independently of the mic levels. Each music input and each
mic input shall also have a rear panel gain control: the front panel
music input need not meet this requirement. Two-band equalisation

adjustment shall be provided on the front panel for the summed

microphone signals. The front panel shall also be provided with a
master level control and two-band equalisation: these controls shall

affect the nal mixed output. Visual indication of output signal level
shall be provided on the front panel by not less than ve LEDs: the

LEDs indicating the two highest levels shall be orange and red, the
remainder shall be green.

15 V phantom power shall be available at each microphone input:
this shall be selectable for each input by moving internal PCB

jumpers. Each microphone input shall have a simple high-pass lter

to remove frequencies below 100 Hz: this shall be selectable for

each input by moving internal PCB jumpers. Each microphone input

shall be provided with a front panel switch to enable/disable the
input: the switch shall be internally illuminated when the mic input
is active.

Front panel switches shall congure the mixer-amplier to perform

the following functions: i) detection of a signal on any mic input will
automatically reduce the music level by approximately 30dB, ii)
detection of a signal at one line input will automatically override
all others, even if unselected. The switches shall be internally
illuminated when the priority function is enabled. An external
control input shall be provided to allow muting of the music

source by a re alarm or other external emergency system. It shall

be possible to additionally mute the microphone inputs by this

command input by moving an internal PCB jumper.

The mixer-amplier shall be available in two models with different

output powers of 120 W or 240 W, measured into a four ohm

load. The mixer-amplier shall be capable of driving either low

impedance (four ohms or higher) loads, or 100 V-line, 70 V-line or

25 V-line line systems via an internal transformer tted as standard.

It shall not be possible to use both types of output simultaneously.
The 100 V, 70 V and 25 V transformer outputs shall be available
on a rear panel output connector of the detachable multipin type,
shrouded by a screw-attached safety cover. The low impedance
output shall be available on a separate detachable multipin
connector.

A switchable high-pass lter shall be tted to each channel to

remove LF content below 70 Hz (-3 dB) to minimise transformer

saturation in 100/70/25 V-line systems; this lter shall be by­passable by moving an internal jumper. A xed limiter circuit shall

shall operate in such a manner that it is not possible for clipping

to occur in the output stage. The amplier shall also incorporate

protection circuitry that isolates the output in the event of

DC being detected at the amplier output or if the internal

temperature exceeds a safe operating level.

The mixer-amplier shall be equipped with a balanced line level
output from the pre-amplier stages: this shall use a detachable

multipin connector on the rear panel.

The mixer-amplier shall be built in a 2U steel chassis for mounting

in a standard 19” rack. Temperature-controlled forced-air fan

cooling with front-to-rear airow shall be employed. The front
panel shall be tted with a mechanically latching mains power
switch and there shall be visual indication of the amplier’s active

status.

It shall be possible to specify either version of the amplier to

operate from an AC mains supply voltage of 115 V or 230 V, with a
tolerance of +/-10% applying to both voltages.

The mixer-ampliers shall be the Cloud VMA120 (120 W output)

and the Cloud VMA240 (240 W output).