User guide

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REAR PANEL CONNECTIONS - INDIVIDUAL CHANNEL JACKS 14) XLR Input Jack This 3-Pin Female XLR jack is used to bring balanced signals into the channel. Normally, microphones are connected to this jack, and are selected by having the front-panel Line switch in the UP position, but hi-level signals can be accommodated by pressing the front-panel Line switch (#6). Input imped- ance is approx 3K ohms. 15) Line Input Jack This 1/4” TRS jack is used to bring line-level balanced or unbalanced signals into the channel. This jack is selected with the front-panel Line switch (#6). If nothing is plugged into this jack, the XLR signals are normalled into the TRS circuit which allows the front-panel Line switch to do double-duty as a PAD switch. Input impedance is approx 15K ohms, so Hi-impedance instruments (guitars, bass) should not be plugged in here. No damage will occur, but the sound will not be optimum for those instruments. Use an outboard preamp or buffer amplifier for these types of instruments. 16) Channel Output This 1/4” TRS jack is used for the channel output. Signals from the channel can be fed into individual tracks for recording. Nominal output level is +4dBu. Output impedance is 100 ohms, ground-compensated, impedance balanced. This allows this jack to be connected to balanced and unbalanced inputs without concern. Use a balanced (2-wire w/shield) cable for all connections for best results.
REAR PANEL CONNECTIONS - MASTER JACKS 17) Expansion In / Out jacks These 8-Pin mini-DIN jacks are used to tie SP-828 units together. When connected, the “Slave” SP-828 will send its signals to the “Master” SP-828. L/R mix and Solo signal and control signals are sent out of the Expansion Out jack of the “Slave” SP-828, and are received on the Expansion In jack of the “Master” SP-828. By chaining additional units together, up to 32 channels (4 units) can be mixed together and monitored from one master unit. The mini- DIN connector cables should be shielded and wired Pin-to-Pin and limited to 3 feet in length for best results. 18) L/R Insert Jacks The 1/4” TRS jacks are used to insert processing gear into the L/R mix. Stereo compressors or EQs are typically used here. The insert point is located after the mix amp and before the main level control. Tip is Send, Ring is Return, Sleeve is audio ground. Send impedance is 100 ohms, return impedance is 10K ohms. 19) Main Output Jacks These 1/4” TRS jacks are the main mixed outputs of the unit. The L/R outputs are available here as well as a summed-mono mix of the L & R outputs. The overall level is controlled by the front-panel L/R level control (#11). Nominal output level is +4dBu. Output impedance is 100 ohms, ground-compen- sated, impedance balanced. This allows this jack to be connected to balanced and unbalanced inputs without concern. Use a balanced (2-wire w/shield) cable for all connections for best results. 20) AC Power In jack This 5.5mm barrel jack brings low-voltage AC power into the unit. 18 volts at 750mA is required for proper operation. Only use the supplied AC adaptor from Studio Projects.
sp828 manual.indd 2/22/05, 11:06 AM8-9