Peavey Electronics Corporation

Other

John H Roberts

Jack C Sondermeyer

Ronald David Goss

Apparatus and method of measuring acoustic properties of a drumhead of a drum are disclosed. The acoustic properties are measured by exciting the drumhead with a source of energy and detecting the acoustic energy emitted by the drumhead. The acoustic energy emitted by the drumhead may be measured using a microphone or other acoustic sensor. The use of multiple energy sources provides isolation of acoustic energy and allows measurement of local resonance of the drumhead.

Apparatus and method for measuring the acoustic properties of a membranophone

A heat sink alignment apparatus having an internal chamber with a plurality of heat sinks placed at an angled relationship to one another creating a tunnel through which air streams flows. At least one heat source is attached to a heat sink. A plurality of air streams enter the heat sink alignment apparatus through an ambient air intake and over a fan into the tunnel. The tunnel gradually narrows thereby increasing the velocity of the air streams which increases the cooling of the heat source. The narrowing shape of the tunnel creates turbulence within the plurality of air streams increasing the transfer of heat to various airstreams from the heat sink thereby lowering the temperature of the heat sources also.

Heat sink alignment

A compound differential circuit detects the highest relative signal of a plurality of input signals. Peak detector circuits including a sensing diode and a capacitor, are employed to produce a control signal. A switch receives the corresponding control signal. One switch is active at a time in response to the highest control signal. An LED connected to the activated switch is illuminated so that a visual indication of the highest input signal is displayed. In another embodiment, a feedback sensor for a graphic equalizer is disclosed.

Circuit for providing visual indication of feedback

A proportional, multichannel gain sharing audio circuit has a gain control in the computing leg so that additional weight may be accorded the channel so that the channel is allocated greater gain in proportion to the total amount of signal available to all of the channels combined. Weighting may be adjustable and more than one channel may have such a feature, so that a hierarchy of priority is possible.

Automatic mixer priority circuit

A clipping circuit is coupled across the bass feedback shunt capacitor in an amplifier circuit to effectively reduce only high level bass signals while allowing level high frequencies to pass and allowing full boost to low level, low frequency signals.

Bass clipping circuit

A linear display device provides a floating bar type of display for instantaneous peak values and instantaneous average values of an audio signal. Pairs of respective peak and average comparators are coupled to a source of fixed value bias voltages. The comparators produce outputs when the peak value and the average value of the audio signal exceeds the bias voltage. A logic circuit connected to outputs of each pair of comparators provides an output only when the bias voltage exceeds the instantaneous peak value.

Linear array level meter displaying multiple audio characteristics

A gated multi-channel amplifier system comprises a plurality of musical performance amplification channel means each responsive only to high threshold level sound input for producing amplified sound output, and another channel comprising a vocal/announcer amplifier channel means capable of responding to announcer sound input of both low threshold level and high threshold level for producing an amplified announcer sound output, and means for gating the vocal/announcer amplification channel means to respond to announcer sound input of low threshold signal level only in the absence of response by the other musical performance amplification channel means.

Multiple channel gated amplifier system

This invention concerns, in a current-controlled amplifier circuit, the combination of output amplifier means having an input conductor and having an output conductor for converting a signal at the input conductor of the output amplifier means to a current amplified signal, feedback means connected between the output and input conductors of the output amplifier means and including a differential pair of semiconductors having a control current output, for presenting a signal at the input conductor of the output amplifier means which is the product of an input signal to the amplifier circuit and the ratio of a reference current to the control current and for substantially eliminating dc input at the input conductor of the output amplifier means and setting the quiescent currents of the semiconductors of the differential pair substantially equal.

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Hickory, MS, United States of America

John H Roberts