Prophet 12 Module Troubleshooting 28 April 2022 13:31 Updated If the unit is not booting: There is no bootloader mode for the Prophet 12 module, so the unit will need to be returned to Sequential for reprogramming. Please contact Sequential support for resolution. OS file and installation instructions If the unit boots but has an issue, perform initial settings first: INITIAL SETTINGS Start by removing all connections (MIDI/USB, pedals, audio) from the rear of the instrument except for power. Reset global parameters: press GLOBAL and scroll to Reset Globals, then press Reset/soft button 1. Now press Confirm. Press GLOBAL to exit the global menu. Connect a set of headphones to the headphone output. Initiate the basic patch: press GLOBAL, then navigate to Basic Patch, and press Write Now. Next, proceed to the appropriate section below according to the issue described: I. Audio Issues (voices not triggering or not sounding correctly) A. Perform Initial Settings Verify if the issue is still present. If so, proceed to step B. B. Oscillator/Filter Calibration Start Calibration: Press GLOBAL and scroll to Autotune Filters. Press Start Tuning. Calibration will start and progress will be shown on the screen. If calibration stalls/does not complete, take note of the text on the display. If calibration completes and no problem is detected, reconnect audio cables to the instrument’s main outputs, and power cycle the unit, as per on-screen instructions. Verify if the issue is still present. If so, proceed to sections C, D, E, or F based on problem description. C. Some Voices Sound Quiet, Compare to Others If the problem is only present with a single cable connected to the main output, set press AMPLIFIER and set SPREAD to minimum. *SPREAD sequentially pans the voices further into the stereo field left to right as the voice count increase. If only a single cable is connected to the main outputs, voices panned to the opposite side will sound more quietly. D. Distortion In Audio Outputs Is distortion present on headphone output? If so, press AMPLIFIER and try turning down the PROG VOLUME amount, and set DISTORTION to 0. If no distortion is present on headphone output, verify correct cables are in use (TS unbalanced) and that the instrument is connected to the appropriate audio interface/mixer input (Line level input). If distortion is still present, check the instrument with another set of cables and audio interface/mixer inputs. If distortion is still present on the Main L/R outputs, reduce VOLUME to below 50%. If distortion ceases, this indicates that repair is necessary. E. 6 Of 12 Voices Missing Check to see if cables are plugged only into B outputs. If so, reconnect cables to Main Outputs. Check to see that STACK and SPLIT are turned off. Connect a MIDI keyboard to MIDI In jack and check for all 12 voices from the Main outputs. F. Output Level Mismatch Differences in output level between the left and right main outputs of 1-2dB are within expected tolerances. This is due to the analog nature of the amplifier circuitry in our instruments. II. Tuning Issues A. Perform Initial Settings Verify if the issue is still present. If so, proceed to B and C. If the issue is still present after steps B and C, proceed to step D. B. Filter Autotune Start Calibration: Press GLOBAL and scroll to Autotune Filters. Press Start Tuning. Power cycle the unit, as per on-screen instructions. Check if the tuning is immediately better after completing calibration. If so, run calibration over a larger range of operating temperatures. Repeat calibration whenever you notice tuning instability: upon power on, after it's being on for a period of time, and when there is any environmental/temperature change. Over time and as a larger number of calibrations are run, you should not need to calibrate as often. **If calibration does not complete successfully, check the MIDI and Pedal inputs on the rear of the unit. If MIDI or a pedal is connected, remove these and attempt calibration again.** C. Clear Filter Calibration Clear Calibration: Hold UNISON + HOLD and press GLOBAL. Select CLEAR CALIBRATION and press Clear Cal. *Note that no on-screen confirmation of the clearing will be displayed -- press GLOBAL again to exit Debug Menu. After clearing calibration data, you will need to run calibration extensively to stabilize the tuning. III. MIDI Issues A. Perform Initial Settings Verify if the issue is still present. If so, depending on the description of the problem, proceed to step B, C, D. B. Instrument Not Outputting MIDI Press GLOBAL, then scroll to MIDI Out Select and verify it is set to the port being used to transmit MIDI data. If it is not set to the correct port, use the Off/On soft encoder to set MIDI OUT to MIDI, USB, or MIDI + USB. Press GLOBAL to exit globals. C. Instrument's Voice Count is Halved This is due to a MIDI feedback loop. When the synth is actively connected to a DAW via USB or MIDI, turn LOCAL CONTROL off with steps 2-4. Press GLOBAL, then scroll to select LOCAL CONTROL. Use the MODE soft encoder to set LOCAL CONTROL OFF. Press GLOBAL once to exit globals. D. Pots/Encoders Not Updating Correctly This is due to a MIDI feedback loop. When the synth is actively connected to a DAW via USB or MIDI, turn LOCAL CONTROL off with steps C2-4. IV. Button Issues A. Perform Initial Settings Verify if the issue is still present. If so, proceed to step B. B. Button Cleaning Routine The buttons on our instruments are self-cleaning. In most cases, buttons that are intermittent/non-operative can be resolved by being fully depressed 50-100 times. If the operation improves but is still intermittent, repeat step B1. V. Pot/Encoder Issues A. Perform Initial Settings Verify if the issue is still present. If so, depending on the description of the problem, proceed to step B, C, D. B. Pot/parameter Value Changes On Its Own Turn the pot back and forth across its full range of travel 50-100 times. Set pot to minimum or maximum setting and check whether pot/parameter continues to change on its own. If it does not, set the pot to its midpoint and check whether the pot/parameter continues to change on its own. If the parameter continues to change on its own, the pot requires replacement. C. Encoder Value Does Not Update On Every Detent Due to the manner in which the encoders are scanned, it is possible for an encoder to not update a value for 1-2 detents. This is within expected tolerances and is not considered a fault. D. Pot Feels Wobbly Excessive horizontal pressure applied to a pot may cause the pot shaft to loosen within the housing of the pot’s enclosure. It is advised to not apply excessive non-axial force when turning a pot. If the pot works correctly to set value (no jumps in value or value change without physical movement), then the pot is working correctly and no fault is present. Related articles Prophet-6 Module Troubleshooting Prophet-5/10 Keyboard Troubleshooting Discontinuation of Evolver Service OB-6 Keyboard Troubleshooting Prophet X/XL Troubleshooting