Abstract: A pitch modification system for signals received from a tape player converts analog signals received from the player to binary digital form and stores them in sequential addresses in a memory unit at a rate set by a first clock. Output signals are produced by sequentially reading the stored information at a different rate as set by the frequency of a second clock, the ratio between the two clock frequencies causing the desired change in pitch with respect to the original signal. The output signal is converted from digital binary representation to an analog signal by a D/A converter. A detecting means is employed to detect no-signal conditions and generates an automatic reset signal which equalizes the two clock frequencies to restore the system to a zero-shift condition attendant to the appearance of silent passages on the tape.

Abstract: A channel-selection control system for a frequency synthesizer type receiver which comprises: a frequency synthesizer (1); a plurality of switches (SW.sub.1, SW.sub.2) corresponding to channels having different broadcasting programs, respectively; a plurality of memories (ROM.sub.1, ROM.sub.2) associated with the respective switches (SW.sub.1, SW.sub.2) and each storing data signals (n) corresponding to broadcasting waves for one broadcasting program; a clock generator (CK) for producing clock pulses; a counter (CNT) adapted to count up by the clock pulses for producing address signals (m) for the memories; a comparator (COMP) for comparing a level value of a received signal outputted from said frequency synthesizer (1) with a preset reference level value; and a gate circuit (G.sub.

Abstract: An electronic attenuator includes voltage controlled attenuators, memory circuits and a plurality of switches. The memory circuit stores a level signal selectively provided by setting the switches and supplies it to the voltage controlled attenuator which in response to the level signal attenuates an input signal applied thereto.