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  1. Greetings from Raleigh-Durham area. I repair vintage HiFi as a hobby. Few years ago I repaired a MXR-130 and loved the innovative technology used in the PS and FM stereo noise reduction design. Recently bought a Carver MXR-2000 that has loud hum in power transformer with -69vdc and +69vdc rails measuring at -/+99 volts on both. TRIAC was replaced with no change. All Zener diodes voltages ZD801 through ZD805 are normal. Appears that voltage monitoring circuit may be driving TRIAC to 100% duty cycle. I see design uses optocoupler to provide signal to control drive to the Q801 through Q804 to determine switch on/off time to the TRIAC to maintain the +/-69VDC. Is it safe to remove the TRIAC so I can power up rig to T/S the regulator circuitry? Thanks in advance for any suggestions. Mark
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