Electro-Voice CPS 3 - Manual (Page 3)

CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Front Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
DESCRIPTION
First of all, we would like to express our thanks and at the same time congratulate you on the decision to
buy one of our CONTRACTOR PRECISION SERIES power amplifiers.
Electro-Voice CONTRACTOR PRECISION SERIES amplifiers are made to meet the highest require-
ments of any on-the-road application. Thus they provide on-board protection against thermal and
capacitive overload, short-circuit and the occurrence of HF or DC at the output. Additionally, special
circuitry prevents the output-stage transistors from being damaged by Back-EMF. During soft start,
delayed switching of the power outputs is accomplished via relays and a limiter controls the initial current
inrush, preventing the mains fuse from being blown during the power-on operation.
The mechanical construction as well is carried out following the highest precision standards of the industry.
The robust steel chassis provides extreme rigidity and it is meant to live through any hard wearing condition
of a touring application. Thermal stability is guaranteed by two 4-Mode silently running fans that offer the
possibility to also use the amplifiers in a studio environment.
The extensive comparator circuitry constantly monitors the input and output signals and activates the
internal limiters whenever a non-linear operational state is encountered. This provides reliable protection
of the connected loudspeaker systems against overload and clipping. The sound quality of the CON-
TRACTOR PRECISON SERIES power amplifiers is superb. Using comprehensive dimensioned power
supply units with low-interference toroidal transformers gains a headroom that exceeds the nominal power
handling capacity by far. No V/I-Foldback-Limiter circuits are employed within the power amplifiers, making
it possible to operate the amps on complex loads up to ±90° phase angles without a problem.
The input facilities are carried out as balanced XLRF-type sockets while the Direct-Outs – on which the
carried-through signals are present – come as XLRM-type connectors. Using the Input Routing-switches
lets you determine if the CONTRACTOR PRECISION SERIES amplifiers are operated in DUAL (stereo)
or PARALLEL (monaural) mode; “mono-bridged” operation is also possible.
The dB-scaled level controls are to be found on the rear panel. These potentiometers guarantee precise
and reliable operation. The easy readable LED display offers quick optical information on the power
amplifiers’ momentary operational mode. For each channel individually the display shows whether they
are operational, a signal is present at the outputs, when the limiters are activated, and whether one of the
protection circuits has been engaged or not. The power outputs CANNEL A, CHANNEL B and BRIDGED
OUT are carried out as Speakon connectors. A ground-lift switch that separates the enclosure from the
appliance’s ground potential and therefore helps to eliminate ground noise loops and the mono bridged
mode switch are also located on the rear panel. In normal operation all CONTRACTOR PRECISION
SERIES power amplifiers can be used to drive loads down to 2 ohms; in bridged mode the minimal load
is 4 ohms. All amps are equipped with extremely silent running fans providing front-to-rear air circulation,
guaranteeing trouble-free operation even in smaller power amplifier rack systems.
Studying this owner’s manual carefully will provide you with further and more detailed information about
the CONTRACTOR PRECISION SERIES power amplifiers. Thus we recommend to keep on reading,
assuring you that the Electro-Voice CONTRACTOR PRECISION SERIES power amplifiers will provide
you with a lot of fun and satisfaction in your work.
DESCRIPTION
9