User manual ELECTRO-VOICE 654A DATASHEET

[. . . ] Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus that produce heat. Only use attachments/accessories specified by the manufacturer. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped. For US and CANADA only: Do not defeat the safety purpose of the grounding-type plug. [. . . ] Coupling is possible under the following restrictions: only identical amplifiers or power amps can be connected. Since doubling the output voltage comes along with serial connection, it is necessary to switch the outputs of both amplifiers to 50 V (see also paragraph 8), resulting again in an overall output voltage of 100 V. In this case the speaker chain's minimum load impedance is 50 ohms // 50 nF. The input level controls of the corresponding channels of the 654A have to be set to equal values (refer also to the PROMATRIX handbook). This results in the following output combinations with a single 654A: 4 x 100 W or 2 x 100 W + 1 x 200 W or 2 x 200 W. diagram 5 Possible output configuration of the 654A 5. 5 MONITOR output The MONITOR output of the 654A is configured as monitor bus. It gets connected to thePROMATRIX Manager DPM 4000 via the serial port REMOTE CONTROL (13). If a floating output is needed, the output is prepared for retrofitting a monitor output transformer. In this case the extension NRS 90227 is necessary (see paragraph 9. 4). The low-impedance monitor output is electronically balanced. Therefore, the connected cables may be up to approx. The PROMATRIX Manager DPM 4000 (see PROMATRIX handbook) offers connection for monitor amplifiers; which can be set to input-monitoring or output-monitoring for the desired amplifier channel. 6. Switching the output voltage to 20 V, 50 V or 70 V should only be carried out by qualified DYNACORD service personnel. Caution Unplug the mains cord and disconnect batteries before opening the appliance! - for opening the appliance, please remove the 9 screws on the top of the appliance that lock the cover plate. - the four output transformers 356762 are located on the left hand side of the appliance. They are numbered 1, 2, 3, and 4; starting from the rear cover plate of the appliance. - for changing the output voltage (see diagram 6) you have to unsolder the orange wire attached to the transformer's soldering tab 19 (100 V) and solder it instead to the required soldering tab (70 V, 50 V or 20 V). - closing the appliance: use the 9 screws M3 x 6 DIN 7500 to reattach the cover plate. diagram 6 Switching the output voltage at the output transformers 356762 diagram 7 Output configuration settings of the amplifiers (rear view) 28 Note After changing the output voltage, use a waterproof marker pen to note the correct, newly set value on the label-field OUTPUT VOLTAGE (20) on the rear of the appliance. Additionally note the corresponding output configuration (see diagram 5) on the label OUT CONFIG TYPE (20). According to the description in diagram 7, adjust the switches S801 and S802 on the printed board assembly 89019. 2 that are located next to the transformers on the bottom of the appliance's enclosure (refer also to paragraph 5. 4 ). diagram 8 Printed board assembly 89019. 2 showing the position of the switches S801 and S802 9. Additional Functions And Features (refer to qualified service personnel only!) 9. 1 NRS 90206 Pilot Ton Surveillance Using the extension-kit NRS 90206 provides continuous monitoring (surveillance) of the individual amplifier channels. This is achieved by sending an ultra low-level 19 kHz pilot tone through the device. It enters the signal path post level controls, runs through the amplification stages and gets filtered out and evaluated at the output. [. . . ] 19"-Flightcase Or 19"-Rack System Installation Caution Operating the 654A without cover-plate is not admissible. When incorporating the 654A into a 19" flightcase or 19" rack system, make sure to leave room for sufficient air-flow. Between the amplifier's rear plate and the inside-wall of the surrounding enclosure has to be at least 60 mm x 330 mm of space until up to the enclosures top or its ventilation gaps. At least 100 mm of space should be left above a rack system to guarantee sufficient air circulation. Since, during the operation of the 654A the environmental temperature within the rack closet may increase by about 10° C, minding the maximum allowable temperature values for other equipment that is installed into the same rack system or enclosure is of major importance. [. . . ]