AMPLIFIERS OWNER'S MANUAL Stereo Power Amplifiers SPA Series SPAPOWER AMPLIFIER SERIES STEREO Congratulations on your choice of stereo power amplifiers -- you have purchased one of the finest stereo amplifiers on the market today. This unit was developed using the expertise of professional sound engineers and working musicians. You will find that your new NADY AUDIO SPA 850/1400/2400 has superior performance and greater flexibility than any other amplifiers in its price range. Please read this manual carefully to get the most out of your new unit. Thanks for selecting NADY AUDIO as your choice in amplifiers. FEATURES Offering top power, superior performance and full professional operating features in a roadworthy compact chassis, the SPA Series are perfect for even the most demanding sound reinforcement installation and touring applications. The operating instruction in this manual are for the SPA 850, SPA 1400 and SPA 2400 power amplifiers. The operation and functions of these units are the same, except as noted. · Continuously variable speed fan with back-to-front air flow · Full operating features: user-defeatable clip limiter; switchable 30Hz low-cut filter; balanced XLR and 1/4" TRS inputs; detent volume controls; stereo (dual-channel, parallel-input, or bridged mono operating models with selector switch; binding post and Neutrik SpeakonTM outputs; ground-lift switch · Complete, advanced safety/reliability features: soft-start turn on; noise-free on-off; built-in DC offset; independent DC and thermal overload protection on each channel; short circuit and speaker protection; DC servo operation; built-in current limiter · Parallel outputs allow "daisy chaining" amps · ~115V (60Hz)/~230V (50Hz) AC select switch · Clip and Signal LED indicators for each channel · Durable double rack space (2U) steel casing · SPA 850 -- 2 x 350W @4, 2 x 425W @2 Bridge mono: 600W @ 8, 850W @ 4 SPA 1400 -- 2 x 500W @4, 2 x 800W @2 Bridge mono: 1000W @ 8, 1400W @ 4 SPA 2400 -- 2 x 750W @4, 2 x 1400W @2 Bridge mono: 1600W @ 8, 2400W @ 4 3 CONTENTS FEATURES ..................................................................3 WARNING ....................................................................4 FRONT AND REAR CONTROLS ................................5 INSTALLATION ............................................................7 CONNECTIONS ..........................................................8 BLOCK DIAGRAM ......................................................10 SPECIFICATIONS ......................................................11 Date of Purchase __________________________________________ Dealer's Name ____________________________________________ City ______________________________________________________ State____________________Zip ______________________________ Model # __________________________________________________ Serial # __________________________________________________ WARNING An equilateral triangle enclosing a lightening flash/arrowhead symbol is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure which may be of sufficient magnitude to constitute a risk of electric shock. ATTENTION: RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR An equilateral triangle enclosing an exclamation point is intended to alert the user to the presence of important operating and service instructions in the literature enclosed with this unit. IMPORTANT SAFETY INSTRUCTIONS When using this electronic device, basic precautions should always be taken, including the following: 1. Read all instructions before using the product. 2. Do not use this product near water (e.g., near a bathtub, washbowl, kitchen sink, in a wet basement, or near a swimming pool, etc.). 3. This product should be used only with a cart or stand that will keep it level and stable and prevent wobbling. 4. This product, in combination with headphones or speakers, may be capable of producing sound levels that could cause permanent hearing loss. Do not operate for a long period of time at a high volume level or at a level that is uncomfortable. If you experience any hearing loss or ringing in the ears, you should consult an audiologist. 5. The product should be positioned so that proper ventilation is maintained. 6. The product should be located away from heat sources such as radiators, heat vents, or other devices (including amplifiers) that produce heat. 7. The product should be connected to a power supply only of the type described in the operating instructions or as marked on the product. Replace the fuse only with one of the specified type, size, and correct rating. 8. The power supply cord should: (1) be undamaged, (2) never share an outlet or extension cord with other devices so that the outlet's or extension cord's power rating is exceeded, and (3) never be left plugged into the outlet when not being used for a long period of time. 9. Care should be taken so that objects do not fall into, and liquids are not spilled through, the enclosure's openings. 10. The product should be serviced by qualified service personnel if: A. The power supply cord or the plug has been damaged. B. Objects have fallen into, or liquid has been spilled onto the product. C. The product has been exposed to rain. D. The product does not appear to operate normally or exhibits a marked change in performance. E. The product has been dropped, or the enclosure damaged. 11. Do not attempt to service the product beyond what is described in the user maintenance instructions. All other servicing should be referred to qualified service personnel. 4 FRONT AND REAR CONTROLS 4 1 2 3 1 FRONT PANEL 1. POWER SWITCH To turn the unit ON or OFF, press the upper or lower portion of this button. Before turning on the amplifier, check all connections and turn down the level controls. A momentary muting is normal when turning the amplifier on or off. (Caution: Always turn on your power amplifier last, after all your other connected equipment, and always turn off your power amplifier before your other connected equipment.) 2. POWER LED INDICATOR This LED illuminates when the power is turned "ON". 3. CLIP (PEAK) LED INDICATORS These LEDs illuminate if any section of the power 5 amplifier's output are within 3DB of clipping. Occasional blinking of the LEDs are acceptable, but if they remain on more than intermittently you should turn down either the power amplifier's level controls or reduce the output level of the preceding component to avoid audible distortion. 4. SIGNAL LED INDICATORS These LEDs illuminate to confirm the presence of an input signal greater than 100 mV at that channel of the amplifier 5. LEVEL CONTROLS These control the level of signal coming into each channel. The actual voltage gain of the amplifier is shown in dB. Turn these controls counterclockwise if the peak LEDs illuminate steadily (indicating too strong an input signal). 6 9 7 8 REAR PANEL 6. CIRCUIT BREAKER A bimetallic circuit breaker is provided for protection of the amplifier. Press to reset if it trips. If it continuously trips upon resetting, refer servicing to qualified personnel. 7. POWER CONNECTOR The cord connector is used to connect the AC power source to your power amplifier. (CAUTION: DO NOT REMOVE THE CENTER GROUNDING PIN.) 8. GROUND LIFT SWITCH: Switch to right to disconnect the chassis from ground if necessary to eliminate hum caused by ground loops. 5 9. AC VOLTAGE SELECTOR SWITCH: Before plugging in the power cord, check to see that the unit is set for the proper voltage for your area: ~115V (60Hz) or ~230V (50Hz). A cover plate is provided to ensure that this switch is not accidently reset or tampered with between uses. 10. L/R CHANNEL OUTPUT CONNECTORS (SpeakonTM & Binding Posts) The SpeakonTM and binding post (banana jack) outputs are compatible with a speaker load of 2 or greater (4 or greater for bridged operation). Connections are as depicted on the rear panel and in the following CONNECTIONS section on page 8 of this manual. FRONT AND REAR CONTROLS 11. BALANCED INPUT CONNECTORS (1/4" TRS & XLR) These 1/4" (6.3mm) TRS (Tip/Ring/Sleeve) phone jacks and XLR jacks are compatible with balanced inputs and are wired as Tip/Pin 3 = (+), Ring/Pin 2 = (-), and Sleeve/Pin 1 = Ground. Normal maximum input level at clipping is 1.15V RMS (+ 4dB). Input impedance is 10K Ohms. Since the TRS phone jacks and XLR jacks are wired internally in parallel, you can parallel this unit with another amplifier by using either the LINE 1/4" jack or the XLR jack (depending on which you're using to input your signal) to output the signal to the input jack of the other amplifier. The 1/4" TRS phone jacks can also be used for unbalanced inputs. For TRS phone plugs, simply connect the unused side of the balanced input to ground. For 1/4" TS phone plugs, no change is necessary for compatibility with this input. Balanced input signals are recommended as they are less prone to AC hum. For long cable runs a source of less than 600 ohms output impedance is needed to avoid signal loss. For short cable runs an unbalanced signal input should be suitable. For stereo (two-channel) operation, use the inputs for both CH-A and CH-B; for parallel or bridged mono operation, use only CH-A input. (See 13-MODE SELECTOR SWITCHES below for more explanation.) 12. CLIP LIMITER SWITCH This switches the internal Clip Limiter ON or OFF for both channels. The limiter prevents excessive signals from overloading the amplifier (and thus flattening the peaks of the waveform and introducing distortion) by automatically lowering the amplifier gain to minimize overdrive. This limiting is primarily used to protect full-range speakers from high frequency distortion or damage to the horns caused by bass overdrive. However, when driving a subwoofer, defeating the limiter can produce a desired extra "punch" to bass instruments, such as kick drums. 13. MODE SELECTOR SWITCH The SPA Series amplifiers offer 3 modes of operation: PARALLEL, STEREO & BRIDGED. Slide the switch to one of the three positions for you application. · PARALLEL (MONO) INPUT -- This mode allows both channels to operate in parallel with the same signal and without requiring a Y-cord. In this mode the inputs for both channels are internally connected, so that you only need to feed a signal into one of the channels. This still allows independent control of each channel. It also enables easy "daisy-chaining" with other amps by using the other set of input connectors. (Note: Do not select this "Parallel" mode when feeding the amplifier 2 separate signals.) 6 (Note: Do not use both unbalanced and balanced cables in the same set-up as that can unbalance all the connections when daisy-chaining, resulting in hum.) · STEREO INPUT -- This is the most common mode generally used, and allows independent control of 2 separate signals such as stereo playback, main and monitor live mixes, and bi-amp operation (highs in one channel and lows in the other). · BRIDGED MONO -- This mode combines the power of both channels to drive a single speaker. In this mode the amp produces 4 times the peak power and 3 times the sustained power into a 4 or 8 ohm speaker than each channel can deliver separately in stereo or parallel mode. (CAUTION: In this mode the amplifier can deliver high power into a speaker. Make sure that the speaker, connectors and wiring can handle this output. Note that for prolonged overdriven outputs into a 4 ohm speaker the breaker may trip, so care must be taken not to overload the amplifier in such operation.) Connect the input signal to CH-A input for bridged mono operation. 14. LF FILTER (30HZ) SWITCH The low frequency LF filter rolls off frequencies below 30Hz when this switch is turned to the ON position. This filter improves the audio by limiting unwanted inaudible low frequency speaker cone movement. Unless a preceding device, such as a mixer, already has such a 30Hz roll-off, this filter should generally be employed for optimum audio and to protect your speaker from excessive cone excursions beyond its rated limit at sub-audio frequencies. Generally this switch should only be left "OFF" if you are monitoring the whole signal for frequency content, such as for studio playback. 15. FAN The fan speed is varied continuously automatically to maintain the proper internal operating temperature. Rearto-front airflow keeps amps and racks cool. INSTALLATION Rack Mounting The SPA Series amplifiers are designed for standard 19" rack mounting as well as "stack" mounting without a cabinet. Use 4 screws and washers for mounting to the front rack rails. It is also a good idea to support the amps also in the rear, especially for mobile use where the amps will be subjected to shocks. Amplifier Cooling Also pay close attention to the cooling requirements. Since the airflow is from the rear to the front, it is important to keep both the inlet in the rear and the output in the front clear ...