Specifications

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Tweed 5E3 PCB Valve Junior Conversion
Build Manual v3.0 13 Feb 2011
39 of 40
9.3 Power Up with Tubes
9.3.1 The Real Test
Install the tubes! $UHQ¶WWKH\SUHWW\"
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cord in the IEC mains connector.
Secure the black ground lead of your
voltmeter to the chassis star ground lug.
Plug the amplifier into a speaker cabinet.
Match the speaker impedance with the
appropriate output jack. Failure to connect
a speaker will cause harm and eventual
failure of the output transformer.
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position. With your voltmeter, check the
following voltages. Your voltages will be
different !
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pin 7. This is a mistake. Instead you
should find that probing here causes
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the signal path.)
However they should be of the same order.
If a significant deviation from these
readings is observed, turn off the amp,
unplug the mains power and investigate.
To check the heater voltage you need to
measure across the two pads, where
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Turn the power off, disconnect the black
ground lead from the star ground lug, then
power back on & probe with the two. Be
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