User manual RANE MA 6

[. . . ] This means that the amplifier has turned down the input level quickly and automaticallyto avoid clipping. See elsewhere for further explanation of the MA 6 limiters and how best to use them. CLIP INDICATORS: Each of these red LEDs will light whenever that particular channel reaches -3 dB before actual clipping. Rear Panel 1. INPUTS: These are 1/4" stereo (RTS) jacks, which are automatic balanced/unbalanced. [. . . ] NOTE -- AUTOMATIC INPUT COUPLING The MA 6 uses switching input jacks to automatically make internal connections between each pair of channels: 1 & 2, 3 & 4, and 5 & 6. Whenever a signal is plugged into an oddnumbered channel (channel 1, forexample), the next even-numbered channel is automatically driven INVERTED (out of phase, so to speak) as long as no input is plugged into its own jack (in this case channel 2). As soon as a signal is plugged directly into the even-numbered channel, the internal connection is defeated and both channels operate independently. You can use this feature a couple of ways: 1. AUTOMATIC BRIDGING Plug into any odd-numbered channel, but DO NOT plug an input into the next even-numbered channel. Then connect a single 8 ohm or greater speaker cabinet between the two HOT terminals of the above two channels of the MA 6--you are now running bridged power (300 watts into 8 ohms) into the speaker cabinet. RUN TWO CHANNELS MONO FROM A SINGLE INPUT: You can run any pair of channels with a single input, thereby driving two speaker cabinets with the same signal. Run the input into the odd-numbered channel ONLY-do not plug anything into the next evennumbered channel. Then connect one speaker normally to the odd-numbered output terminals, but connect the second speaker IN REVERSE: speaker positive to MA 6 ground (­), amplifier positive to speaker ground. This way both speakers will be in phase and you will have saved yourself a cable and two connectors. FAN INFORMATION The cooling fan in the MA 6 requires a bit of special attention during installation. There should be adequate room between the fan filter and whatever may be located behind the amplifier for sufficient cooling air to enter the unit. This is normally quite easy to accomplish in most rack installations. This fan is of the two speed variety, which means that under most operations the fan will run at a very low speed, switching to high gear only during extended high power demands. The amplifier will deliver a full 100 watts into six discrete eight or four ohm loads for several minutes before switching to high speed. Once the high power demand has been reduced or removed the fan will return to low speed in a matter of a minute or two. BRIDGED BIAMPED DIRECT Diagram 1. Direct, biamp and bridged operation. Diagram 2. Stereo Biamped Operation The MA 6 will drive an active two way stereo system when wired as shown. The high-frequency drivers are run direct from channels 1 and 2. The low frequency drivers, requiring much more power, are then run from two bridged pairs: channels 3 & 4 bridged to one woofer and channels 5 & 6 bridged to the second woofer. CAUTION: 8 OHMS IS THE LOWEST IMPEDANCE THAT CAN BE DRIVEN BY THE MA 6 IN THE BRIDGED MODE. IF THERE ARE TWO WOOFERS IN EACH BASS CABINET, BE SURE THAT THEY ARE WIRED IN SERIES IF THEY HAVE AN INDIVIDUAL IMPEDANCE OF LESS THAN 16 OHMS EACH. OPERATION USING THE BUILT-IN LIMITERS The built-in limiters in the MA 6 allow a significant increase in usable volume levels without clipping The limiters DO NOT effect dynamic response, distortion or noise level of any material below about 90 watts output level. [. . . ] It is not likely that you will blow many breakers at all, if any, but it is wise to be aware of the possibility so that you don't panic if it happens. SPECIFICATIONS MA 6 SPECIFICATIONS POWER OUTPUT all channels driven, 20-20kHz: -100 watts minimum RMS per channel into 8 ohms -150 watts minimum RMS per channel into 4 ohms -300 watts minimum RMS per two-channel bridged operation into 8 ohms FREQUENCY RESPONSE: 5Hz - 80 kHz. +0/ -3 dB TOTAL HARMONIC DISTORTION: less than 0. 2 % (1 kHz) INTERMODULATION DISTORTION (60 Hz : 7 kHz @ 4:1): less than 0. 1% SIGNAL-TO-NOISE RATIO: better than 96 dB (EIA A-weighted) SENSITIVITY: +0 dBm (. 775V3 for rated power output INPUT IMPEDANCE: greater than 9k ohms DAMPING FACTOR: 300:1 at 1000 Hz INPUTS: "A" RTS phone jacks, automatic balanced/unbalanced OUTPUTS: Terminal blocks CROSSTALK: better than -60 dB at 1 kHz, any channel to any channel DIMENSIONS: 5 1/4" H x 19" W x 11 1/2" rack depth, rear support mount holes provided LIMITER PERFORMANCE: Range: 15 dB Maximum input level at clipping: +15 dB (4. 4v) Attack time constant: 10 ms Decay time constant: 10 ms Detection method: full-wave peak SPEAKER IMPEDANCE: No less than 4 ohms for single channel operation No less than 8 ohms for bridged operation LED THRESHOLDS. : Signal present: -20 dBm (78mV. ) Limit: 90W output into 8 ohms (26. 8 VRMS) single operation 270W output into 8 ohms (46. 5VRMS) bridged Clip: 3 dB before actual clipping. OUTPUT RELAY: Activates approximately 10 seconds after power is applied; drops out immediately after turn-off; drops out any time there is DC output voltage or high level subsonic signals. WEIGHT: 44 Ib dry Features and specifications subject to change without notice. Diagram 2. [. . . ]