Cloud Electronics CV250 - Manual (Page 3)

2 CV AMPLIFIER USER GUIDE
Mains Connections Mains Connections Mains Connections Mains Connections
The amplifier is provided with 3 pin Euro connector mounted on the rear panel, a suitable mains lead with
plug is supplied.
CAUTION: This amplifier must be CAUTION: This amplifier must be CAUTION: This amplifier must be CAUTION: This amplifier must be earthed. earthed. earthed. earthed.
All the CV amplifiers can be supplied to operate on 220v or 240v A.C. mains supplies. Refer to the service
manual if the supply voltage requires changing.
Level Control Level Control Level Control Level Control
Independent level controls are provided for channels A & B. These would normally operate in the fully
clockwise position. The limiter operates in the post level circuitry and is not affected by the position of the
level control.
Limiter Limiter Limiter Limiter
The limiter circuit uses a studio quality VCA with comprehensive side chain circuitry. 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 prevents "control voltage induced distortion" at low frequencies. All this adds up to a studio quality
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 particularly 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.
To avoid the risk of unauthorised adjustment the limiter on-off switches are mounted on the power amplifier
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 Limiter switching Limiter switching:::: To switch the limiter in or out of circuit, first remove the top cover. Locate the switch
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 Limiter Threshold Limiter Threshold:::: This control adjusts the point at which limiting commences. It is factory set to limit the
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.