Marshall 1987 Plexi HT Voltages - diyAudio
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Old 4th March 2011, 06:24 PM   #1
kgc-jr is offline kgc-jr  United States
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Default Marshall 1987 Plexi HT Voltages

Does anyone know or have measured the HT power supply voltages on a Marshall Model 1987 Plexi, as indicated on the attached drawing at points A, B, C, D, & E? If anycan provide those measurements or give me a good guess, that would be most helpful. Thanks in advance.

KGC
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Old 4th March 2011, 08:08 PM   #2
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B+ (A) should be somewhere in the realm of 365-380 volts.
G2 (B) should be about 5-10 volts less.
About 300-330 on the phase splitter supply.
about 20-30 volts less on the next cap after the 10K resistor and
about another 20 volts less on the last supply cap.

This is from my memory so I may be a bit off. I will check my voltage charts tonight when I get home.
Hope this helps.... Daniel
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Old 4th March 2011, 08:11 PM   #3
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Here's a voltage chart I found online...
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Old 4th March 2011, 08:29 PM   #4
llwhtt is offline llwhtt  United States
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The later 1987s had approx. 430VDC at point "A". Using the voltage chart you can figure out how much current each stage draws to complete the rest of the points.

Craig
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Old 4th March 2011, 08:31 PM   #5
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Old 5th March 2011, 01:06 AM   #6
kgc-jr is offline kgc-jr  United States
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Great, thanks guys! This helps alot.

KGC
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