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Lab12 suara 2 x 50W
Class A Power Amplifier
Bias Setting
Please contact with a qualified person or your local dealer if you are not sure about this
procedure.
You can easily set the bias of each tube from the back panel of amplifier.
You must use a DC multimeter. Please set multimeter in 5vDC range.
Turn on amplifier (with connected speakers at outputs and connected inputs without signal).
Connect minus (black) terminal of multimeter at any minus (black) speaker bind. Connect plus
(red) terminal of multimeter at test point of tube you need to bias.
Use trimming screwdriver to set the voltage at 950mV DC (KT150 setting) from corresponding
trimmer.
Follow the same procedure for each tube.
Wrong bias will destroy your tubes and possibly your amplifier. Always adjust new tubes bias
current immediately after turning on.
Repeat bias procedure at least 3 times the first 5 hours of using.
For the safety of your equipment
! Make sure that all of your equipment is turned off before any connection.
! To avoid damaging your speakers you have to turn on suara some seconds after
turning on your preamplifier and turn it off some seconds before turning off your
preamplifier.
! Never turn on suara without connected speakers or preamplifier on it. It is
possible to damage tubes or even output transformers.
