© 1995-2007 CORNELL Musical Equipment Design & Development
5
Controls
1. Input -
Hi & Lo [applies to each channel]
Both inputs offer high impedance connections for instruments.
The Hi input provides 6dB more gain than the Lo input.
2. Volume
Adjusts the gain of the pre-amp and is used to set the overall volume of the
amplifier.
3. Tone
Adjusts the amount of high and low frequency boost.
4. Channel 2
The controls are the same as for Channel 1.
The overall tone of Channel 2 is brighter than Channel 1.
5. 18/20 Switch
This changes the rectifier from valve (18) to semiconductor (20). The valve
rectifier gives a bluesy ‘sag’ in output, while the semiconductor rectifier has a
faster response and less sag, improving transient attack.
6. Low-High Switch
This reduces the maximum power from 20 Watts in the ‘high’ position, to 5W
in the ‘low’ position.
7. Output Connectors
The two output jacks are wired in parallel. The output impedance switch
allows an 8 Ohm or 4 Ohm load to be used.
8. Mains Indicator
When illuminated, this shows that the valve heaters are on, and that there is
power to the amplifier.
9.
Mains Fuse
The fuseholder contains the mains fuse for the amplifier. The mains fuse
protects the amplifier from electrical faults.
Replace a failed fuse only with the same type and rating.
Do not operate the mains switch without a 30 second delay between
operations.
There is an internal thermistor to reduce mains surges. This
protects the amp and helps to ensure a long life for the components. The
thermistor works by introducing a resistance in the circuit when the power is
switched on. Within a few seconds the thermistor heats up and its resistance
reduces, allowing the full current to flow into the mains transformer. After
switching off the amp, it takes a few seconds for the thermistor to cool down
and to return to its initial, protective resistance value.