User manual RANE RPM 88

[. . . ] HARDWARE MANUAL RPM 88 PROGRAMMABLE MULTIPROCESSOR INPUT -4 -12 -48 1 2 3 4 5 6 7 8 AES3 A LOCK B -4 -12 -48 PRESET OUTPUT -4 -12 -48 1 2 3 4 5 6 7 8 A AES3 B -4 -12 -48 PROGRAMMABLE MULTIPROCESSOR RPM 88 Peak dBFS VIP/VOP RW 485 ETHERNET STATUS POWER 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 88. 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. [. . . ] The second stage contains a Digital Trim control located immediately after the A/D converter. 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 fecund 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 88'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 88. See the RaneNote "Interfacing AES3 and S/PDIF", available from Rane's web site (www. rane. com/library. html), for more information about interfacing consumer S/PDIF gear to the professional AES3 standard. Use the AES3 I/O to: · Connect multiple RPM 88s together to create a 2-channel digital "bus" between devices. · Connect directly to the AES3 output of a digital mixing console. · Connect directly to the AES3 input of a DAT machine for recording purposes. · Connect to an external A/D or D/A converter, effectively adding two more analog inputs or outputs. Incoming Sample Rate and Word Length The AES3 input has a built-in sample rate converter capable of accepting incoming sample rates up to 96 kHz. Sample rates exceeding the RPM 88's internal 48 kHz sample rate are automatically downsampled. Outgoing Sample Rate and Word Length The AES3 output uses a fixed 48 kHz sample rate and 24-bit word length. Manual- Control Connections Versatile Input Port (VIP) Eight logic input pins are provided, each capable of accepting DC voltage between 0 and 5 volts. VIP pins are used with contact closure switches for Preset recall, or with potentiometers for remote Level control. [. . . ] For example, if pin 3 is shorted to GND and pin 6 is then shorted to GND, Preset 6 is recalled. 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. [. . . ]