Interchangeable Microphone Preamplifier Cartridges With Unified Gain Control

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Solution Overview

Problem

Traditional audio preamplifiers require multiple devices and complex connector changes to test different sound technologies, lacking a generic system to control various preamplifier technologies with a single gain selector.

Innovation Solution

An audio preamplifier with a removable cartridge containing the preamplification circuit, allowing easy swapping of preamplification functions without changing the chassis or disconnecting connectors, using a generic chassis with a single gain selector to adjust different preamplifier technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional audio preamplifiers use permanently installed electronic modules in mechanical chassis, then each preamplifier produces a specific sound characteristic, but sound engineers must buy multiple devices and repeatedly unplug/replug connectors to test different sound technologies

Engineering Contradiction:

Improveability to test different sound technologiesVSAvoidnumber of devices and connector operations

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The preamplifier system is divided into two independent parts: a fixed chassis containing common components (power supply, gain selector, output stage) and interchangeable cartridges containing different preamplification circuits. This segmentation allows the preamplification function to be changed by simply swapping cartridges rather than replacing entire devices or reconnecting connectors.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The chassis is designed as a universal platform that can accommodate multiple different preamplification cartridges through a standardized connector interface. The single gain selector on the chassis can control the gain of any inserted cartridge, making the chassis multi-functional and eliminating the need for separate gain controls on each cartridge.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If each preamplifier circuit has its own resistive ratio for gain control, then the gain can be adjusted according to the preamplifier's design, but it is not natural or obvious to control several different preamplifiers with different technologies with a single gain selector

Engineering Contradiction:

Improvesingle gain selector controlVSAvoidcompatibility with different preamplifier technologies

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The gain control mechanism uses a standardized resistive ratio in the chassis gain selector that works across different cartridge technologies. The system achieves this by placing the gain control potentiometer in the chassis rather than in each cartridge, and by designing the signal path so that the gain selector's resistance ratio can effectively control the gain of various preamplification circuits regardless of their internal design.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If audio preamplifiers use permanently installed electronic modules, then the preamplifier circuit is fixed, but changing the preamplification function requires changing the entire chassis

Engineering Contradiction:

Improvemodular cartridge designVSAvoidtime to change preamplification function

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4125210A1Audio preamplifier with interchangeable cartridge for microphone and kit comprising same

Publication Date: 2023.02.01 ELDORA PROD

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AI summary

The invention relates to an audio preamplifier (1) for a microphone, comprising: a chassis (2) having at least one audio input (17) and at least one audio output, a control panel (3) having a gain selector (10) located on one face of the chassis (2), the chassis (2) further having a housing within which a first connector is located; and a cartridge (6) comprising a preamplifier circuit and a gain control circuit, the cartridge (6) further having a second connector complementary to the first connector, the cartridge (6) being configured to be removably inserted into the housing of the chassis (2) so as to connect the first and second connectors. The invention also relates to an audio preamplifier kit comprising an audio preamplifier (1) and several additional cartridges.