Could a failing Internal Modulation Trimpots cause the MXR M169 CARBON COPY ANALOG DELAY to have symptom: Carbon Copy Delay Time Fluctuating?

The Carbon Copy features two internal trimpots (Speed and Width) that control the Low Frequency Oscillator (LFO) responsible for time modulation. If the 'Mod' switch is engaged, these components intentionally oscillate the BBD clock frequency, causing the delay time to fluctuate rhythmically. Adjusting these trimmers or disengaging the front-panel 'Mod' button stops the fluctuation.

Could a failing Delay Control Potentiometer cause the MXR M169 CARBON COPY ANALOG DELAY to have symptom: Carbon Copy Delay Time Fluctuating?

The delay time is determined by a DC reference voltage passed through the main Delay knob. If the resistive track or wiper inside this potentiometer has oxidized or worn out, it can produce 'jumping' or unstable resistance values, causing the BBD clock driver to receive an erratic signal and resulting in unstable, non-rhythmic delay time fluctuations.

Could a failing Modulation Selector Switch cause the MXR M169 CARBON COPY ANALOG DELAY to have symptom: Carbon Copy Delay Time Fluctuating?

The top-mounted 'Mod' button is a latching switch that engages the LFO circuit. If this switch is partially engaged or has internal contact failure, it may intermittently activate the modulation circuit, causing the user to experience unexpected or fluctuating delay times without deliberate input.

What is the most likely root cause for a MXR M169 CARBON COPY ANALOG DELAY with symptom: Carbon Copy Delay Time Fluctuating?

The Carbon Copy features two internal trimpots (Speed and Width) that control the Low Frequency Oscillator (LFO) responsible for time modulation. If the 'Mod' switch is engaged, these components intentionally oscillate the BBD clock frequency, causing the delay time to fluctuate rhythmically. Adjusting these trimmers or disengaging the front-panel 'Mod' button stops the fluctuation.

MXR M169 CARBON COPY ANALOG DELAY Carbon Copy Delay Time Fluctuating

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System Nominal

The MXR Carbon Copy is designed with a modulation feature that cyclically varies the delay time to simulate tape-style 'wow and flutter.' If the 'Mod' button is depressed, the delay time will rhythmically fluctuate by design.

NO REPAIR ACTION REQUIRED. PHYSICS CHECK CONFIRMED.

// NOTICE: This report is generated by an Agentic AI Engineer utilizing probabilistic modeling.

PartSniper is an automated parts recommender service. AI-generated results may not be correct. This data is not a substitute for professional engineering advice or manual inspection. Always verify part compatibility and disconnect power before any repair. PartSniper is not liable for inaccuracies, injury, or damage.

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MXR M169 CARBON COPY ANALOG DELAY Carbon Copy Delay Time Fluctuating

System Nominal