| 摘要 |
PURPOSE: To obtain high-level sounds by controlling a fixed tone by a dual input part and controlling a variable tone by a regenerating feedback circuit and filtering a bass response by negative feedback and allowing all of respective tone quality adjustments to act on the base of a transistor TR. CONSTITUTION: A fixed tone control input part consists of two pats on the high frequency side and the low frequency side, and a capacitor C13 allows high frequencies to pass through, and a C14 and a C12 discharge undesired frequencies to the earth to produce sounds on the low frequency side. An input gain control circuit 36 is connected to a first amplifier 32, and a negative feedback circuit 38 connects a second amplifier 34 to the first amplifier 32, and a regenerative feedback circuit 40 connects the second amplifier 34 to the first amplifier 32 through a tone control circuit 42. That is, a TRQ1 functions as a high-gain emitted-grounded amplifier, and high frequencies are directly coupled to the collector of a TRQ2 through a C7, and this signal is amplified by the TRQ2 and is fed back and coupled to the TRQ1 by the regenerative feedback circuit consisting of a C10, C11, a resistance R12 and a C8. |
