LEEDS WORLD HIZ PRE User Manual - page 12
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6. Carefully slide the front panel / top cover forward away
from the rear chassis.
7. Gently remove the vacuum tube. Care should be taken to
properly align the pins on the tube to the corresponding
holes in the receptacle. Make sure the tube is completely
seated in the receptacle.
8. Re-assemble the unit using steps 6-1 in reverse order,
Care must be taken to align the LEDs, power switch, and
potentiometer posts in the front panel holes.
Experiment! Your HiZ Pre can accept the 12AT7 and 12AU7
vacuum tubes. Try swapping out the 12AX7 for one of these
lower gain tubes to experiment and customize your sound.
Vacuum tubes do not have an infinite life span, and must be
periodically replaced. Primary causes of tube failure are:
1. Mechanical failure – bumps, excessive vibration, and
mishandling of the HiZ Pre unit can cause the vacuum
tube to fail. Care must be taken to mount the unit in a
vibration free environment, and avoid hard bumps or
knocks when transporting the unit.
2. Aging – Tube aging occurs as the unit is in use. Be careful
to not leave any tube driven device powered on
indefinitely. Use the power switch to power down the unit
to preserve tube life.
3.7
Power Supply
The HiZ Pre is accompanied by a 16VAC, 1000mA external
wall transformer. To ensure safe proper operation, do not use
any other wall transformer other than the unit provided.
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