User manual RANE RPM 44

[. . . ] HARDWARE MANUAL RPM 44 PROGRAMMABLE MULTIPROCESSOR INPUT -4 -12 -48 1 2 3 4 AES3 A LOCK B -4 -12 -48 PRESET OUTPUT -4 -12 -48 1 2 3 4 A AES3 B -4 -12 -48 Peak dBFS VIP/VOP RW 485 ETHERNET STATUS POWER PROGRAMMABLE MULTIPROCESSOR RPM 44 QUICK START This section is intended to help you make the physical connections and software manipulations necessary to get up and running with your sleek new RPM 44. If you don't read the entire Hardware Manual, at least read this section. It is also recommended that you read the Quick Start section of the Drag Net Software Manual. If the Drag Net software is not yet installed on your computer, please install it now. [. . . ] Analog Inputs and Outputs The RPM 44 has four balanced analog Inputs and four balanced analog Outputs. For each Input or Output Euroblock connector: · Connect the (positive) audio line to the `+' terminal. · Connect the (negative) audio line to the `­' terminal. · Connect the cable shield to the ground terminal. For those installations where the RPM 44's internal shieldto-chassis connection causes interference, connect each shield directly to the chassis PEM nut located above each Euroblock connector, keeping the shield wrapped around the audio conductors as much as possible. For optimum Electromagnetic Interference (EMI) immunity, connect the shields at both ends of the cable. See RaneNote 110 "Sound System Interconnection" for more information on system connections and proper grounding practices. Analog Input Stage The analog input uses a two-stage gain approach. The first stage contains a software controlled analog line/mic pad and switchable-gain preamp. The second stage contains a Digital Trim control located immediately after the A/D converter. The RPM 44 takes the following approach to input clipping: If you've set the Analog Gain so the input stage is not clipping, it is not possible to clip the A/D converter, since there is no additional gain between the initial input stage and the A/D converter. The Digital Trim control, located after the A/D converter, can be set to clip the signal to your heart's content, so adjusting this trim to provide the hottest signal to the DSPs without clipping is the most important step when setting up gain structure. For this reason, a dedicated meter displaying the signal level being passed to the DSPs is provided in each Analog Input block. If the DSPs are working with a clipped signal, the audio is (as expected) distorted and none too pretty, but it is not a drastic, damaging sound. And while it's technically possible to write a DSP algorithm to emulate the glorious clipping distortion of vacuum tubes, it's not particularly useful for an installed sound system, where the DSP power could be put to better use removing that annoying 500 Hz feedback from the Pope's podium mic. Plus, they don't yet make DSP chips with gold-plated substrates for those celestial highs and that moist, supple midrange. Analog Output Stage Each analog output also uses a two-stage gain approach, which differs slightly from that of the analog input stage. The first stage is a Digital Trim control located immediately before the D/A converter. The second stage is an analog trim control located immediately after the D/A converter. Attenuation is handled in the analog domain, while boosting (when the incoming digital signal is low) is handled in the digital domain. Boosting and attenuating using this two-stage approach helps maintain the RPM 44's excellent noise performance. Digital (AES3) Input and Output AES3 is a popular 2-channel (stereo) digital audio interface commonly found on professional digital audio equipment (digital mixers, DAT machines, etc. ). Each channel of the AES3 digital stream is treated independently within the RPM 44. [. . . ] If pin 3 is closed and then pin 2, nothing happens -- Preset 2 is not recalled. This permits a hierarchy of Presets when using VIP pin closures for tiered priority paging. Since there are only eight VIP pins, you can only recall up to eight Presets using switch closures. There are four ways to recall more than eight presets. [. . . ]