User manual ELECTRO-VOICE DPA 4260

[. . . ] OWNER'S MANUAL DPA 4245 / DPA 4260 POWER AMPLIFIER Features · · · · · · · · · · · · · · · · · · · · · · 2 x 450 watts output power capacity DPA 4245 2 x 600 watts output power capacity DPA 4260 floating 100 V / 70 V / 25 V power outputs (isolated outputs) low impedance outputs (direct outputs) bridged mode operation, switchable all outputs are protected against idling and short-circuit mains supply 230 V AC 50/60 Hz POWER REMOTE function service mains switch active ventilation via 2 temperature-controlled DC-fans electronically balanced inputs routing switch for parallel linked operation input gain controls integrated audio limiters power-on switching noise suppression protection circuitry: DC/HF, Back-EMF, output voltage overload limiters, initial inrush current limiter, output peak current limiter 18 dB/oct. LO-cut filter at 45 Hz SIGNAL and LIMIT indication for optical monitoring thermal overload protection for the heat sink and the internal power supply, with PROTECT-function inputs transformers for balanced, floating operation are optionally available XLR-type and binding post clamping input connectors 19" frame size, 3 HU 15 CONTENTS Description . 17 18 19 19 20 27 43 44 48 IMPORTANT SAFETY INSTRUCTIONS The lightning flash with arrowhead symbol, within an equilateral triangle is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintance (servicing) instructions in the literature accompanying the appliance. 1. [. . . ] This control should be positioned between the 0 dB and the -6 dB marks to prevent distortion in source devices. The labeling indicates the actual attenuation applied to the internal specified factor of amplification. Input Routing If the switch is set to parallel/mono, the input connectors CHANNEL A and CHANNEL B are electrically linked for direct parallel operation. With only a single audio signal source connected, both channels are driven, while their volume levels are still individually controlled via the level controls A and B. If the switch is set to its dual/stereo position, channels A and B are separately amplified (two channel or stereo mode). Power Outputs A&B The loudspeaker cables are connected to the power amplifier through high-performance binding posts ­ with the necessary screw-plugs being supplied. For connection purposes, it is possible to remove the 12-pole terminal plug. Cables with a maximum diameter of 2. 5 mm2 can be utilized. To provide flexible connections, all floating output voltages ­ 25 V, 70 V, and 100 V (ISOLATED OUTPUTS) ­ as well as the low-impedance output (DIRECT OUTPUTS) of both channels are directly accessible. figure: power outputs of the DPA 4260 20 Power Outputs ­ AUDIO TRANSFORMER OUTPUTS The two integrated output transformers convert the power amplifier's nominal output voltage to the commonly used loudspeaker line voltage standards ­ 25 V, 70 V, and 100 V. These voltages are simultaneously present at the correspondent floating outputs of the binding post strip. The two power amplifier channels can be operated using any possible output voltage combination. Simultaneous operation of low impedance loudspeaker systems and floating loudspeaker lines on a single power amplifier channel is possible as well. Caution It is possible that during operation shock-hazard output voltages can be present at the power output connectors (>34 V peak value). Therefore, the connected loudspeaker lines have to be installed in accordance to applicable security standards and regulations. When installing and operating 100 V-loudspeaker networks, compliance to the VDE regulation DIN VDE 0800 is mandatory. Especially, if a 100 V-loudspeaker network is included in alarm system applications, all security standards have to be in accordance to the security class 3 standard. Before the first operation of the power amplifier, the loudspeaker terminal strip has to be covered using the supplied protection cover. Power Outputs - Isolated Outputs 70 V and 100 V To reduce line attenuation effects when the distance between power amplifier and loudspeaker systems exceeds 50 meters, it is recommended to employ loudspeaker systems with 100 V or 70 V line transformers, which also allows conveniently distributing the output power to the individual loudspeaker systems. It is possible to connect as many loudspeaker systems until the total power consumption of the loudspeaker network equals the nominal power handling capacity of the power amplifier; while not declining the nominal load impedance of the power amplifier outputs. For details on nominal power handling capacity and nominal load impedance of the amplifier's individual power outputs, please refer to the specifications in the appendix. figure: example configuration ­ DPA 4260 with 100 V loudspeaker systems ­ maximum load using 30 W / 100 V and 60 W / 100 V loudspeaker systems 21 Power Outputs - Isolated Outputs 25 V The floating 25 V output is mainly used for driving low impedance loudspeaker systems (4 - 16 ohms). Because of the effect of line attenuation, the distance between power amplifier and loudspeaker systems should not exceed 50 meters. It is further important that the total impedance of the entire loudspeaker network does not decline the nominal load impedance of the 25 V output. For details on the nominal load impedance of the 25 V output, please also refer to the specifications in the appendix. figure: example configuration ­ DPA 4260 with 8 ohms and 16 ohms loudspeaker systems at maximum load Power Outputs ­ DIRECT OUTPUTS In addition to the output transformer equipped outputs and for driving low impedance, high performance loudspeaker systems, the power amplifier's direct, low impedance outputs are carried out as well, offering a minimal load impedance of 4 ohms. Each power amplifier channel is capable of simultaneously driving loads at the direct output and at the isolated output. But it is of major importance that the overall power consumption of the connected loudspeaker systems or lines does not exceed the output power capacity of the power amplifier. Example: If a loudspeaker system with 8 ohms and a nominal power handling capacity of 300 watts is connected to the DPA 4260 channel A Direct Output, this equals exactly half of the power amplifier's output power capacity since the minimal load impedance for each channel is 4 ohms. [. . . ] It signals that the protection circuitry is in working order. Power ON Indicator This LED lights when the power amplifier is connected to the mains and its power switch is set to the ON-position. If the indicator does not light although the power amplifier is switched on, the appliance is not connected to the mains or the primary fuse is blown. 24 Protection Circuitry The DPA-Series power amplifiers are equipped with extensive protection circuitry: · · · · · · · · · initial current inrush limiter power-on delay RF and DC protection Back-EMF protection limiters for the audio signals output peak-current-limiters thermal overload of the heat sink thermal overload of the mains transformer output voltage overload limiters High-level signals in the low frequency range can drive the output transformers of power amplifiers that do not provide audio signal limiters into saturation, resulting in nasty distortion and high thermal load of the power amplification stage. The audio signal limiters of the DPA-Series power amplifiers are designed to quickly identify the occurring saturation of the core of an output transformer. [. . . ]