认真的,再多说两句,有些机器,调偏流不是凭想象的,重要的事再说一遍,在确认偏置电路阻值没有超出误差的情况下,要按照厂家的建议值来调,举个例子马克3系,调偏流需要配合几个测量点来调整,不是简单的一改锥,偏流与声音,在维护手册有描述:
At any instant, the ideal amount of output stage bias is determined by both the voltage and the current required by the output. Other variable bias systems fail to live up to their promise because they merely track the input signal in a more-or-less proportional fashion, failing to take into account the specific needs of the loudspeaker's impedance.
Rather than having only one fixed bias at which it operates , or varying the bias level as a function of the input signal only (resulting in a system that spends most of its time either over- or under-biased), the proprietary adaptive biasing scheme developed by Madrigal looks at both the input and the output, to maintain the correct bias at all times, this adaptive biasing system has been hailed as a breakthrough in output stage design.
The 300 series amplifiers therefore enjoy the sonic advantages of a Class A output stage without incurring the substantial inefficiencies and consequent thermal problems of fixed-bias Class A operation. Uniquely, this continuously variable adaptive biasing scheme never allows the output devices themselves to be reverse-biased. This approach results in greatly reduced dynamic distortions, and a sweeter sound that exhibits a greater sense of ease at all volume levels. 作者: muse007 时间: 2017-4-21 16:15 本帖最后由 muse007 于 2017-4-21 16:19 编辑