Improvements in or relating to devices for controlling the timbre of sounds reproduced by electrical means

摘要

344,373. Shaping networks. DICKER, S. G. S., 20, Holborn, London.-(Naamlooze Vennootschap Philips' Gloeilampenfabrieken; 6, Emmasingel, Eindhoven, Holland.) Sept. 30, 1929, No. 29565. [Class 40 (iv).] A tone control for connection across an impedance, e.g. in an amplifier or loudspeaker, comprises a potentiometer 6, 7 and two branches C, L and C1, L1 each consisting of inductance and capacity, but of low impedance to high and low frequencies respectively. The control is shown connected across the primary of an inter-valve transformer 3 having a volume control 5, 8 connected across its secondary winding.