Electrical musical instrument amplifier having improved tremolo circuit, improved reverberation control, and power reduction circuit for distortion mode operation
US3978421A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1974 |
| Grant date | Aug 31, 1976 |
| Priority date | — |
| Expiry date | Nov 27, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H2210/281
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An electrical musical instrument amplifier is disclosed in which a signal which has been provided by an instrument to a second one of two different preamplifiers for amplification therein is passed to one of the inputs of a summing amplifier together with the output of the first preamplifier, the output of the summing amplifier being coupled through a tube driven power amplifier to a loudspeaker system. The amplified signal from the second preamplifier is applied to a second input of the summing amplifier via a circuit arranged as a voltage divider and having a variable resistance provided by a field effect transistor driven by an oscillator. The modulation provided by the field effect transistor and associated oscillator can be adjusted to provide total phase reversal as well as amplitude modulation when combined with the signal at the output of the second preamplifier, to provide a tremolo or vibrato effect. Improved reverberation control is provided by a control common to the volume controls of both a delayed reverberation signal from the second preamplifier and the combined signal which results when the instrument signal from the second preamplifier is combined with the delayed…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.