| 摘要 |
<p>A semiconductor system analog or digital processor (402) for emulating a vacuum tube amplifier having first distortion (372), tone control (373), and second distortion (374) circuits. The first distortion circuit (372) variably introduces even harmonics and the second distortion circuit (374) introduces even and odd harmonics. The second distortion circuit includes a variable gain circuit using diodes (275-286) and resistors (287-293) to progressively increase output current with increasing input voltage and clipping circuit. A speaker driving a microphone emulation circuit (379) is also provided. A distortion circuit varies the gain and harmonic contents as a function of amplitude, duration and number of cycles. An asymmetrical bias shifting circuit (60, 70) with a limiter also introduces even harmonics.</p> |
