| 摘要 |
A module 106 controlling the quiescent current of thermionic valves 102-105 in a guitar amplifier 101 may be programmed by use of a portable computer 107 which presents a graphical user interface (GUI, figures 6-13) to the user for valve current setting. The range of currents programmable by the user is constrained by the computer to prevent irreparable damage to the valves yet allow current levels associated with desirable overdrive distortion. Excessively high currents may cause undesirable levels of distortion and heat generation, and may reduce the valves output power. Excessively low currents may cause cathode poisoning, which shortens the valves life. The number of amplifier operating hours may be displayed by the computer, and the number of excessive current faults recorded for each valve may also be displayed (figure 5). Footswitch control, which allows a player to select the valves to be used for amplification, may be enabled by ticking a box in the GUI(610,figure 6). |
