built my firtst 1987 circuit plexi. The power transformer is a classic tone with two sets of secondaries. The lower voltage set gives me about 412 vdc and the higher voltage set gives me 478 vdc (these are a little off according to the PT specs chart). Tubes are biased to 39mv. Are these numbers in the normal range? Should I go with one or the other since I do have the option? Or should I start troubleshooting?
The amp sounds pretty damn good w the low voltage, haven't tried the high voltage taps yet.
typical DC voltages for the 50 watt plexi
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Re: typical DC voltages for the 50 watt plexi
stock would be 415-20
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JTM45 RS OT JTM50 JMP50 1959/2203/34/39
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Super 100 amps: 1202-119 & 1202-84
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Re: typical DC voltages for the 50 watt plexi
thats interesting. The kit instructions state around 440vdc. Many guys on here are getting voltages approaching the upper 400's. Is there a right and wrong here? Or a minimum and maximum point to where the amp doesn't perform and sound as it should?
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Re: typical DC voltages for the 50 watt plexi
most originals were around 420v, except the 133 PT that gave around 450v. and some 70s amps had around 380v. 480v is risky with 500v caps
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Super 100 amps: 1202-119 & 1202-84
JTM45 RS OT JTM50 JMP50 1959/2203/34/39
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Super 100 amps: 1202-119 & 1202-84
JTM45 RS OT JTM50 JMP50 1959/2203/34/39
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Re: typical DC voltages for the 50 watt plexi
thanks, Roe. I'm seeing about 466v now (must be settling in??). I might still go back to the low voltage taps just to be safe but it does sound nice and tight right now.