Rane RE 14 Real Time EQ Schematics

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ALIGNMENT PROCEDUREThe only alignments in the RE 27 and RE 14 are the analyzer filter output level trim pots. These are calibrated at the factory to the pink noise in each unit. NOTE: DO NOT RECALIBRATE THE ANALYZER TRIMMERS TO ANY EXTERNAL PINK NOISE SOURCE. CALIBRATE ONLY TO THE UNITS OWN PINK NOISE SOURCE AS DESCRIBED BELOW, TO INSURE PROPER EQUALIZER/ANALYZER MATCHING.1. Using a 1/4" mono patch cord, connect the Pink Noise Out on the rear panel to the EQ Input Push in the BYPASS switch. 2. With the bottom cover removed; turn the unit upside down with the front panel facing you. 3. Set the Curve Select switch to NORMAL and the Window Select switch to the ±1 dB position. 4. Turn up RTA Level controls until the display responds; adjust these such that the most green LEDs are lit. 5. Using the RE 14 schematic diagram, adjust the proper trim pot so that each filter band shows the most stable green LED response. Be sure that all sliders are in the center detent position. In the lower frequencies (below 1 kHz) the inherent crest factor of true pink noise will cause considerable LED flutter. Adjust the trimmers such that green is dominantly on, and that fluctuations cause both red and yellow LED excursions. If you occasionally switch to the ±3 dB setting, it will be easier to tell if one of the lower frequencies is set too high or too low. NOTE: NO ADJUSTMENTS REQUIRED FOR FILTERS ABOVE 500 Hz Test/Troubleshooting Hints1. The RE 27 and RE 14 really contain their own test equipment By patching the Pink Noise Output to the EQ Input with a mono 1/4" patch cord (and no mike plugged in) the entire analyzer/equalizer/pink noise system can be checked and verified. Turn up the RTA and EQ Level controls until the display LEDs respond. With all sliders centered, the display should show all green in the ±3 dB position with proper level settings. Switching to ±1 dB should show mostly green with some LED flutter in the lower frequency bands below 1 kHz (due to inherent crest factor of pink noise showing through the 2 dB window). Moving each slider up and down should produce red and yellow LED response in that band. Switchingto HOUSE CURVE should cause red LEDs to light between approximately the 250 Hz and the 2.5 kHz bands 2. If one or more LEDs is not working be sure to check for DC voltage right at the LED pins, with enough RTA input level to drive that band. If the real cause is defective IC on the analyzer PCB, you will go through the front panel removal and LED replacement for nothing If more. than one LED is out in the same band or two adjacent bands, suspect a defective IC on the analyzer board.

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