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Vintage Morley VBO - Help!

12/20/1999 2:21 AM
Bob Predaina
Vintage Morley VBO - Help!
Hello,  
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I am looking for information related to the old Morley brand pedals that were produced by the Tel-Ray Electronics Company of North Hollywood, CA. Specifically, I would like to find schematics, circuit board information, etc.  
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Specifically, I have a VBO (volume boost) pedal that is in need of some repair. The pedal uses a model RW 1-B circuit board.  
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I have three questions about this board/pedal and I would appreciate any help anyone may be able to offer in answering them.  
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FIRST -  
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The pedal worked flawlessly when I purchased it, but died after its first 10 minutes of use. Dumb luck!  
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I've traced/tested the board, and the power supply/rectifier circuits are working properly.  
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The pilot lamp that was working when I obtained the pedal appears to have burned out. Looking at the internals of the pedal, the pilot lamp also doubles in function as the light source for the photoresistor in the volume control circuit. This would explain why the pedal ceased to function when the pilot lamp burned out.  
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In tracing the supply voltages on the board, approx 35 volts DC appears to be going to the pilot lamp socket.  
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Interestingly, the lamp that was in use was an IEEE type 387, T-1 3/4 midget flanged bulb, rated at 28v, 0.04A, 0.30 MSCP, with a 7000 hr predicted life span.  
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Because 35v is being applied to the bulb, my calculations suggest that when subjected to a 125% overvoltage, the bulb's service life would be reduced to about 7% of its rated life, or about 490 hours.  
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Does anyone know anything about the design specifications of the circuit? I am concerned that: 1) 35 VDC may not be the correct voltage, and 2) the IEEE type 387 bulb may not be the correct bulb for this application.  
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SECOND-  
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The VBO pedal uses a RW 1-B circuit board.  
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Only one-half of the circuit board has been used in the VBO implementation of this pedal. This suggests that at least one of the other Morley pedals (perhaps the power wah, compressor, fuzz, etc.) shared this circuit board. This pedal is just begging to have another circuit soldered into it.  
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I would like to obtain schematics for the other Morley products that used the RW 1-B circuit board so that I can repair this pedal and perhaps utilize the other half of the board which is unoccupied right now.  
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THIRD -  
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has anyone rewired the old 120vAC Morley pedals to convert them to a grounded (3-conductor) circuit? any tips/pointers on this coversion would be appreciated.  
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Bob