Cloud Electronics CV250 User Manual

CV AMPLIFIER

User Guide

Cloud Electronics Limited

140 Staniforth Road, Sheffield, S9 3HF England

Tel [phone]

Fax [phone]

e-mail

web site http://www.cloud.co.uk

[e-mail]

CV AMPLIFIER USER GUIDE 1

Installation

Installation

InstallationInstallation

CV500, 800 & 1000

CV500, 800 & 1000

CV500, 800 & 1000CV500, 800 & 1000
These amplifiers occupy three units of rack space (i.e. 5.25"/133mm). All three amplifiers feature front
entry forced air cooling which enables any number of amplifiers to be racked without the need for
special ventilation provided th at a free flow of air is available at the rear of the rack housing.

All the CV range of a mplifiers are de si gn ed f o r c on t inu ous operation at h igh power levels and wi l l to l er ate
a good deal of abuse. Output short circuits or mis-matched loads, can be tolerated without harm.

Input Connections

Input Connections

Input ConnectionsInput Connections

Inputs to all the amplifiers are con ne cte d via XLR-3-31 type connectors. The input cir cu it is electr onic all y
balanced and where possible, the balanced mode is preferable. If the input is used in the unbalanced
mode, pin 3 must be linked to pin (Ov). The input is then connected to pin 1 (ground) and pin 2 (hot).
When used in the bal anced mode, pin 1 is ground, pin 2 is in-phase, pin 3 in non phase.
Input impedance is 20K ohms balanced, 10K ohms unbalanced.
Provided pin 3 is grounded in the unbalanced mode, the input sensitivity is 0dBu (775mV) for both
balanced and unbalanced modes.

Output Connections

Output Connections

Output ConnectionsOutput Connections

The output from all the CV amplifiers is connected via an XLR-3-32 type connector or binding posts. The
minimum recommended load is 4 ohms. The two output channels must never be connected in parallel.
XLR connections are pin 1 = 0v, pin 2 = phase (hot).

Mode of Operation

Mode of Operation

Mode of OperationMode of Operation

All amplifiers have a 3 position mode switch on the rear panel, adjacent to the Channel B input socket.
Stereo

Stereo

StereoStereo
In the centre position marked "Stereo" the amplifier operates as two independent channels for typical
stereo operation.

Mono

Mono

MonoMono
With the switch in the "Mon o" po si ti on th e ch an nel A inp ut is in te rn al ly c on nec te d to driv e bo th channels
of the amplifier. The front level controls remain in operation as normal and the limiters also work normally
on each channel. When the "Mono" mode is in use, the appropriate LED on the front panel illuminates,
and channel B input is disabled.

Bridge

Bridge

BridgeBridge
With the switch in the "Bridge" position the load should be connected between the two "Hot" output
terminals (XLR pin 2 or Red binding posts). The amplifier then operates as a single channel unit with a
minimum load impedance of 8 Ω. Channel A input socket, limiter and level control are operative, with
channel B input circuits disabled. The "Bridge" LED on the front panel illuminates when the mode switch
is in this position.

Important.

Important. In the bridge mode, the full output of the combined channels is available at the output

Important.Important.
terminals and care m u st be taken to e nsure that the lou dsp eakers are ca pable of han dli ng t h e ava i lable
power.

2 CV AMPLIFIER USER GUIDE

Mains Connections

Mains Connections

Mains ConnectionsMains Connections

The amplifi er is provided wi t h 3 pi n Euro connector mounted on t he re ar pa ne l, a s ui t abl e ma i ns l ea d w ith
plug is supplied.

CAUTION: This amplifier must be

CAUTION: This amplifier must be earthed.

CAUTION: This amplifier must be CAUTION: This amplifier must be

All the CV amplifiers can be supplied to o perate o n 2 20v o r 240 v A.C . main s suppl ies . Refer to the se rvice
manual if the supply voltage requires changing.

Level Control

Level Control

Level ControlLevel Control

Independent level controls are provided for channels A & B. These would normally op erat e in the fully
clockwise position. The limite r op er ates in th e post level circuitry and is n ot af fec t ed by th e posi tio n of th e
level control.

Limiter

Limiter

LimiterLimiter

The limiter circuit us es a studio quality VCA with co mpreh ens iv e side chain circ ui try. The fast attack time
of 0.5ms ensures accurate control of transients, and the release time is program related: Fleeting
overloads recover quickly whilst sustained limiting has a longer release characteristic. A release hold off
circuit preven t s " con tr o l vol t age i nduced distortion" at low f re quencies. All thi s adds up to a s tu dio qu ality
limiter, with very musical performance. When the limiter is correctly set up it is not possible to drive the
amplifier into clipping, this protects the loudspeakers from overdrive, and is par ticularly effective for
tweeter protection.
The limiter is factory set at 0.5dB below the onset of clipping with a 4 Ω load. All amplifiers are supplied
with the limiter circuit switched on.

earthed.

earthed.earthed.

To av oid th e risk of un auth or ised adjustm en t the li mite r on-off switc hes are mo unte d on the powe r ampli fier
printed circuit boards. Each channel can be switched independently. A small LED on the rear panel
illuminates when the limiter is switched into operation.

Limiter switching

Limiter switching:::: To switch the limiter in or out of circuit, first remove the top cover. Locate the switch

Limiter switchingLimiter switching
marked "SW2" which is on the upper main PCB, on the right side when viewed from the front. The switch
on/off position is detailed on the PCB. A small screwdriver is required to operate the switch on channel
B. Insert the screwdriver through the hole adjacent to "SW2" on channel A to operate an identical switch
on channel B. Visual indication of limiter in/out status is provided by small LED's on the rear panel.

Limiter Threshold

Limiter Threshold:::: This control adjusts the point at which limiting commences. It is factory set to limit the

Limiter ThresholdLimiter Threshold
output to 0.5dB below the threshold of clipping when operating into a 4 ohm load. If the amplifier is
operating with a load impedance greater than 4 ohms, a small increase in output can be gained by
adjusting the threshold control. This should only be carried out by experienced technicians, using
electronic test equipment. Refer to the service information for further details.

CV AMPLIFIER USER GUIDE 3

LED Indicators

LED Indicators

LED IndicatorsLED Indicators

Protect:

Protect: The Red "PROTECT" LED indicates the operation of various protection circuits built into the

Protect:Protect:

CV range of amplifiers. It also illuminates when the 5 second switch-on delay is operating.

Signal:

Signal: The Green "SIGNAL" LED illum inates to indi cate no rmal operation of the amplifier and th e prese nce

Signal:Signal:

of an output signal above 20dBm (7.75v).

Peak:

Peak: The R ed " PE AK " LED illum i na te s ap proximately 1 dB be f or e the amplif ier reaches clippin g po i nt. The

Peak:Peak:

reference circuits are load dependant and operate accurately for 4 to 16 ohm loads.
This LED also indicates that the threshold of limiting has been reached when the limiter is

in circuit.
NOTE: If the "PEAK" LED's are on, no damage is being caused to the amplifier, it merely
indicates waveform clipping, or limiting, if the limiter is operating.

Mono:

Mono: The Yellow "MONO" LED indicates that the "Mono" mode is in operation.

Mono:Mono:
Bridge:

Bridge:The Yellow "BRIDGE" LED illuminates when the amplifier is switched into the "Bridge" mode.

Bridge:Bridge:

Protection

Protection

ProtectionProtection

The Cloud CV multiple protection circuits include output open and short circuit protection, thermal sensing
operating inde pe n dently on each ch an n el , D .C l oad p r ote c tio n, 5 second s wit c h -on mute , s ophisticated
Over-current protection.

The CV800 and 1000 also have anti-surge power switch-on units fitted. (Soft-Start).

This product conforms to the f o llowing European Standards

This product conforms to the f o llowing European Standards

This product conforms to the f o llowing European StandardsThis product conforms to the f o llowing European Standards

BS EN 50081-1

BS EN 50081-1 : 1992

BS EN 50081-1BS EN 50081-1
BS EN 50082-1

BS EN 50082-1 : 1992

BS EN 50082-1BS EN 50082-1
BS EN 60065

BS EN 60065 : 1994

BS EN 60065BS EN 60065

TO REDUCE THE RISK OF FIRE R E P LACE THE MAINS FUSE ONLY WITH THE SAME TYPE, WHICH MUST BE A CLASS 3, 240 VOLT, TIME DELAY TYPE, RATED

TO REDUCE THE RISK OF FIRE R E P LACE THE MAINS FUSE ONLY WITH THE SAME TYPE, WHICH MUST BE A CLASS 3, 240 VOLT, TIME DELAY TYPE, RATED

TO REDUCE THE RISK OF FIRE R E P LACE THE MAINS FUSE ONLY WITH THE SAME TYPE, WHICH MUST BE A CLASS 3, 240 VOLT, TIME DELAY TYPE, RATEDTO REDUCE THE RISK OF FIRE R E P LACE THE MAINS FUSE ONLY WITH THE SAME TYPE, WHICH MUST BE A CLASS 3, 240 VOLT, TIME DELAY TYPE, RATED

: 1992

: 1992: 1992
: 1992

: 1992: 1992

: 1994

: 1994: 1994

SAFETY CONSIDERATIONS

SAFETY CONSIDERATIONS

SAFETY CONSIDERATIONSSAFETY CONSIDERATIONS

CAUTION

CAUTION - MAINS FUSE

CAUTION CAUTION

AT 5A-CV500, 6.3A-CV 800, 8A-CV1000 WHERE THE MAINS INPUT VOLTAGE IS SET TO 230 Volts ±5%AC.

AT 5A-CV500, 6.3A-CV 800, 8A-CV1000 WHERE THE MAINS INPUT VOLTAGE IS SET TO 230 Volts ±5%AC.

AT 5A-CV500, 6.3A-CV 800, 8A-CV1000 WHERE THE MAINS INPUT VOLTAGE IS SET TO 230 Volts ±5%AC.AT 5A-CV500, 6.3A-CV 800, 8A-CV1000 WHERE THE MAINS INPUT VOLTAGE IS SET TO 230 Volts ±5%AC.

FOR A MAINS VOLTAGE OF 115 Volts ±5%AC. THE FUSE SHOULD B E R ATED AT 8A-CV500, 10A-CV800,

FOR A MAINS VOLTAGE OF 115 Volts ±5%AC. THE FUSE SHOULD B E R ATED AT 8A-CV500, 10A-CV800, 15A-CV1000

FOR A MAINS VOLTAGE OF 115 Volts ±5%AC. THE FUSE SHOULD B E R ATED AT 8A-CV500, 10A-CV800, FOR A MAINS VOLTAGE OF 115 Volts ±5%AC. THE FUSE SHOULD B E R ATED AT 8A-CV500, 10A-CV800,

THE FUSE BODY SIZE IS 20mm x 5mm.

THE FUSE BODY SIZE IS 20mm x 5mm.

THE FUSE BODY SIZE IS 20mm x 5mm. THE FUSE BODY SIZE IS 20mm x 5mm.

- MAINS FUSE

- MAINS FUSE- MAINS FUSE

15A-CV1000

15A-CV100015A-CV1000

CAUTION

CAUTION - SERVICING

CAUTION CAUTION

THIS UNIT CONTAINS NO USER SERVICEABLE PARTS. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONNEL. DO NOT PERFORM ANY SERVICING

THIS UNIT CONTAINS NO USER SERVICEABLE PARTS. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONNEL. DO NOT PERFORM ANY SERVICING

THIS UNIT CONTAINS NO USER SERVICEABLE PARTS. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONNEL. DO NOT PERFORM ANY SERVICINGTHIS UNIT CONTAINS NO USER SERVICEABLE PARTS. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONNEL. DO NOT PERFORM ANY SERVICING

UNLESS YOU ARE QUAL I FI E D TO DO SO.

UNLESS YOU ARE QUAL I FI E D TO DO SO.

UNLESS YOU ARE QUAL I FI E D TO DO SO.UNLESS YOU ARE QUAL I FI E D TO DO SO.

TO REDUCE THE RISK OF FIRE O R EL ECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.

TO REDUCE THE RISK OF FIRE O R EL ECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.

TO REDUCE THE RISK OF FIRE O R EL ECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.TO REDUCE THE RISK OF FIRE O R EL ECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.

- SERVICING

- SERVICING- SERVICING

WARNING

WARNING

WARNINGWARNING

4 CV AMPLIFIER USER GUIDE

Specifications

Specifications

SpecificationsSpecifications

GENERAL SPECIFICATION

GENERAL SPECIFICATION CV500

GENERAL SPECIFICATIONGENERAL SPECIFICATION

INPUT

INPUT Electronically balanced via XLR 3-31

INPUTINPUT

OUTPUT CONNECTORS

OUTPUT CONNECTORS 1 XLR 3-32 & 2 heavy duty binding

OUTPUT CONNECTORSOUTPUT CONNECTORS

PROTECTION

PROTECTION VI Limiting,DC Offset,Thermal

PROTECTIONPROTECTION

LED INDICATORS

LED INDICATORS 'Peak Output', Signal Present' 'Limiter

LED INDICATORSLED INDICATORS

COOLING SYSTEM

COOLING SYSTEM Fan assisted by 120mm low noise fan Fan assisted by 120mm low noise fan Fan assisted by 120mm low noise fan

COOLING SYSTEMCOOLING SYSTEM

DIMENSIONS

DIMENSIONS 483mm x 370mm x 132mm 483mm x 370mm x 132mm 483mm x 370mm x 132mm

DIMENSIONSDIMENSIONS

WEIGHT

WEIGHT 18.5Kgs 19Kgs 23Kgs

WEIGHTWEIGHT

TECHNICAL SPECIFICATION

TECHNICAL SPECIFICATION

TECHNICAL SPECIFICATIONTECHNICAL SPECIFICATION

RATED OUTPUT POWER 4

RATED OUTPUT POWER 4Ω 250 watts per channel 400 watts per channel 500 watts per channel

RATED OUTPUT POWER 4RATED OUTPUT POWER 4

per channel

posts per channel

Shutdown with Auto reset

On', 'Protection Operating'

CV500 CV800

CV500CV500

Electronically balanced via XLR 3-31
per channel

1 XLR 3-32 & 2 heavy duty binding
posts per channel

VI Limiting,DC Offset,Thermal
Shutdown with Auto reset, Soft start.

'Peak Output', Signal Present' 'Limiter
On', 'Protection Operating'

CV800 CV1000

CV800CV800

CV1000

CV1000CV1000

Electronically balanced via XLR 3-31
per channel

1 XLR 3-32 & 2 heavy duty binding
posts per channel

VI Limiting,DC Offset,Thermal
Shutdown with Auto reset, Soft start.

'Peak Output', Signal Present' 'Limiter
On', 'Protection Operating'

RATED OUTPUT POWER 8

RATED OUTPUT POWER 8Ω 135 watts per channel 210 watts per channel 285 watts per channel

RATED OUTPUT POWER 8RATED OUTPUT POWER 8

BRIDGED OUTPUT POWER 8

BRIDGED OUTPUT POWER 8Ω 500 watts 800 watts 1000 watts

BRIDGED OUTPUT POWER 8BRIDGED OUTPUT POWER 8

BRIDGED OUTPUT POWER 16

BRIDGED OUTPUT POWER 16Ω 270 watts 410 watts 570 watts

BRIDGED OUTPUT POWER 16BRIDGED OUTPUT POWER 16

FREQUENCY RESPONSE

FREQUENCY RES P O NSE +0, -1db 10Hz to 50Khz +0, -1db 10Hz to 50Khz +0, -1db 10Hz to 50Khz

FREQUENCY RESPONSEFREQUENCY RESPONSE

HARMONIC DISTORTION

HARMONIC DISTORTION 0.03% typical 1Khz 8Ω load 0.03% typical 1K h z 8Ω load 0.03% typical 1Khz 8Ω load

HARMONIC DISTORTIONHARMONIC DISTORTION

INPUT SENSITIVITY

INPUT SENSITIVITY 0dBm - 775mV 0dBm - 775mV 0dBm - 775mV

INPUT SENSITIVITYINPUT SENSITIVITY

INPUT IMPEDANCE

INPUT IMPEDANCE 20KΩ Balanced

INPUT IMPEDANCEINPUT IMP E DANCE

SIGNAL TO NOISE RATIO

SIGNAL TO NOISE RATIO 100dB below rated output

SIGNAL TO NOISE RATIOSIGNAL TO NOISE RATIO

OUTPUT RISE TIME

OUTPUT RISE TIME 3µs (10% to 90%) of 1v 1Khz 3µs (10% to 90%) of 1v 1Khz 3µs (10% to 90%) of 1v 1Khz

OUTPUT RISE TIMEOUTPUT RISE TIME

SLEW RATE

SLEW RATE 45 V/µs 45 V/µs 45 V/µs

SLEW RATESLEW RATE

LIMITER THRESHOLD

LIMITER THRESHOLD 0dBu to -10dBu 0dBu to -10dBu 0dBu to -10dBu

LIMITER THRESHOLDLIMITER THRESHOLD

COMPRESSION RATIO

COMPRESSION RATIO 50 : 1 50 : 1 50 : 1

COMPRESSION RATIOCOMPRESSION RATIO

ATTACK TIME

ATTACK TIME 0.5ms 0.5ms 0.5ms

ATTACK TIMEATTAC K TIME

RELEASE TIME

RELEASE TIME Automatic Signal Related Automatic Signal Related Automatic Signal Related

RELEASE TIMERELEASE TIME

10KΩ Unbalanced

Limiter out. CCIR

20KΩ Balanced
10KΩ Unbalanced

100dB below rated output
Limiter out. CCIR

20KΩ Balanced
10KΩ Unbalanced

100dB below rated output
Limiter out. CCIR

POWER INPUT

POWER INPUT 230 Volts ± 5% 40-60Hz Via IEC

POWER INPUTPOWER INPUT

Cloud Electronics Limited

Cloud Electronics Limited

Cloud Electronics LimitedCloud Electronics Limited

Connector on the rear panel

140 Staniforth Road
Sheffield
S9 3HF
England
Telephone [phone] Fax [phone]

230 Volts ±5% 40-60Hz Via IEC
Connector on the rear panel

230 Volts ±5% 40-60Hz Via IEC
Connector on the rear panel