© 1995-2007 CORNELL Musical Equipment Design & Development
7
Valve Replacement
Valve life varies, depending upon playing style and application. Power valves have
a much shorter life than pre-amp valves, which can last for years. In order to
maintain the optimum performance of your amplifier, the valves should only be
replaced with the same types of valve, as specified below.
The
Plexi 18/20
amplifier has two pre-amp valves (12AX7/ECC83), two power
valves (EL84) and a rectifier valve (GZ34).
Warning
When changing valves, ALWAYS unplug the amplifier, and remember that the
VALVES ARE HOT! Wait for the valves to cool, or replace the valves when
the amplifier has not been used for several hours.
Valve Line-up
Mains
Transformer
Output
Transformer
EL84
EL84
ECC83
Front panel
ECC83
GZ34