Decware TORIIJR Owner's Manual page 24

T O R I I J R O W N E R S M A N U A L
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Once you have your digital multimeter connected to the amplifier and the amplifier is
on, you will see a voltage reading on the meter.
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Make sure your amplifier has warmed up for several minutes prior to making your final
adjustment.
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Using a small flat blade screwdriver insert the screwdriver into the bias adj. slot and
turn counter-clockwise to lower the bias voltage on your meter, or clockwise to increase
the bias voltage on your meter.
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Some EL34 tubes will require the adjustment to be turned fully clockwise as far as it will
go which is normal for some EL34's.
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THE VOLTAGE on the meter should read between 600 millivolts (0.600 volts) and 900
millivolts (0.900 volts). If the meter reads 1000 millivolts (1 volt) or higher you should
turn the bias screw counter clockwise until while trying to reach the ideal figure of 825
millivolts (0.825 volts).
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Below is a chart of what the voltages mean.
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30mA tube bias = 0.606 VDC (approx. 600 millivolts)
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40mA tube bias = 0.825 VDC (approx. 825 millivolts)
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50mA tube bias = 1.040 VDC (approx. 1040 millivolts)
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ALWAYS BIAS ANY TUBE YOU INSTALL TO 40mA / 0.825 VDC
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YOU MUST SET BIAS EVERY TIME YOU CHANGE THE OUTPUT TUBES. Output tubes
should always be purchased and changed in matched quads ONLY. Do not run
matched pairs in the amplifier, only run matched quads. Alternate tubes may be used
in this amplifier such as 6L6, KT77, KT66, 7027. All of these tubes however will require
considerable adjustment to the bias screw when compared to EL34.
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Decware High Fidelity Engineering Co., East Peoria IL, USA www.decware.com