Abstract: The previously unknown cause of significant non-linear distortion by non-linear discrete and stray capacitances located in portions of an amplifier circuit where Miller effect enhancement of such capacitance occurs is minimized by one or more means, such as utilizing unique discrete capacitor arrangements and positioning of transistor terminal leads, and unique printed circuit board constructions and selectively applied solder mask coatings which minimize or eliminate non-linear stray capacitance effects which were not heretofore considered to be a problem in audio amplifier circuits. Non-linearities in capacitance-voltage characteristics are reduced by the reduction in voltage gradients achieved by connecting two or more capacitors in series to produce the overall desired capacitor value heretofore supplied by only a single capacitor.

Abstract: The preamplifier has a first stage or section of low or unity gain, such as an emitter-follower circuit, which also isolates the preamplifier from impedance variations of the cartridge, and with a bandwidth for greater than the audio range to reproduce signals with a very high amplitude, rapidly changing wavefront without slew or amplitude overload distortion. A RIAA high frequency de-emphasis network is coupled between this first stage or section and a second amplifier section. A RIAA low frequency emphasis network is preferably placed in a negative feedback circuit of the latter amplifier section where the feedback circuit does not contain the high frequency components filtered out by the high frequency de-emphasis network. The second amplifier section need not have the bandwidth of the first amplifier stage or section.