Controls
1. Input Hi & Lo.
High impedance input connections for instruments.
Input Hi provides 6db more gain than the Lo input.
2. Volume
Adjusts the overall volume of the amplifier.
3. Bass
Adjusts the amount of low frequency boost.
4. Treble
Adjusts the amount of high frequency boost.
5. Mains Indicator
When illuminated the valve heaters are on and there is power to the amplifier.
6. Standby
Connects power to the valves for operation, use Standby mode for breaks in
usage (e.g. between sets).
7. Output Switch
Output Low position operates the power of the amplifier to one quarter of its
output.
Output High position returns the amplifier to its full output.
8. Line Output
The 3-pin male socket on the base of the chassis next to the output valves is a
600 Ohm line output for use with a mixer or power amplifier.
Pins 2 and 3 are live, and Pin 1 is chassis earth.
9. Impedance Switch
The switch at the base of the chassis next to the line output is an impedance
switch. This switch should be pointing inward for normal use (with 8 Ohms
internal speakers only, or 8 Ohms external speakers with the internal speakers
disconnected); and should be switched to point outward for use when an 8
Ohms extension cabinet is used in parallel with the internal speakers (or some
other combination totalling 4 Ohms). Using the correct impedance selection
enables the amp to deliver maximum power to the speakers.
10. Mains Fuse & Switch
The fuse holder contains the mains fuse for the amplifier and protects the
amplifier from electrical faults.
Do not operate mains switch without a 30 second delay between operations.
An internal Thermistor reduces mains surges which protects the amp and helps to
ensure a long life for the components. It works by introducing a resistance in the
circuit when switched on. Within a few seconds the Thermistor is heated and the
resistance is reduced, allowing the full current flow into the mains transformer.
When switched off it requires a few seconds to cool and return to its initial,
protective resistance value.
