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tion in power associated with normal self-biased amp designs. The
Defender uses two EL34s in a "push-pull" amplifier configuration.
c. Phase Inverter Tube: The phase inverter tube uses a single 12AX7
in what's called a long-tail pair configuration. This results in the
most signal swing possible for driving a power amp and the most
symmetrical drive capability, as well.
d. Preamp Tube 2: This 12AX7 is used in boosting the gain and driv-
ing the EQ. It has the biggest impact on higher gain sounds.
e. Preamp Tube 1: Half of this 12AX7 is the input tube, and as such, is
the most likely to cause microphonic problems. If tube feedback oc-
curs, it can usually be corrected by swapping this first tube with one
of the other tube locations, since they have less gain following them
and are less prone to feedback. The first tube also has the greatest
effect on the "cleaned up" tone of the amp, i.e. the tone when the
guitar is turned down. The other half of this tube is responsible for
providing the extra gain needed for the Boost control.
4 & 6) Speaker Outputs: These 1⁄4" jacks are provided to connect
the internal and/or external speakers to The Defender. The amplifier
should never be operated without a speaker plugged into a speaker
jack.
5) Impedance Selector: This switch is used to select the appropriate
impedance, and is important in achieving the desired results from
The Defender. The correct impedance should be selected using the
Impedance Selector Switch as follows:
a. Internal speaker only: 16 ohm setting
b. Internal speaker + external 16 ohm speaker: 8 ohm setting
c. Internal speaker + external 8 ohm speaker: 4 ohm setting, al-
though it's not matched.
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