Diseño de Preamplificador de Audio

8rony

8rony

NO EXPLIQUES. NO ANALICES. EJECUTA.
PROBLEMA DETECTADO: Los conectores SMA y el clip de batería no están disponibles como designadores en el esquema, lo que bloquea la creación de nets.
SOLUCIÓN OBLIGATORIA: CREA LOS COMPONENTES FALTANTES Y CONTINÚA.
PASO 1: CREAR COMPONENTES FALTANTES
Crear y asignar designadores:
ENTRADAS:
  • J1 → SMA_UP (entrada LDTM-028K)
  • J2 → SMA_DOWN (entrada 2× LDT0-028K en paralelo)
SALIDAS:
  • J3 → SMA_OUT_UP
  • J4 → SMA_OUT_DOWN
ALIMENTACIÓN:
  • BT1 → batería 9 V
  • GND → referencia global
Si ya existen equivalentes, reutilizarlos. Si no, crearlos.
PASO 2: DEFINIR NETS PRINCIPALES
Crear y usar nets explícitas:
  • VCC (9 V)
  • GND
  • VREF (4.5 V)
  • IN_UP
  • IN_DOWN
  • OUT_UP
  • OUT_DOWN
PASO 3: CONECTAR TODO EL CIRCUITO
CABLEAR COMPLETAMENTE:
ENTRADAS:
  • J1 → IN_UP
  • J2 → IN_DOWN
SALIDAS:
  • OUT_UP → J3
  • OUT_DOWN → J4
ALIMENTACIÓN:
  • BT1+ → VCC
  • BT1- → GND
VREF:
  • divisor 100k/100k desde VCC a GND
  • buffer con OPA1642
PASO 4: COMPLETAR CADENA ANALÓGICA
Para cada canal (UP y DOWN), conectar en orden:
  1. Buffer alta impedancia (≥20 MΩ)
  2. Ganancia variable
  3. HPF (~25 Hz)
  4. EQ 3 bandas activa
  5. LPF (~16 kHz)
  6. Buffer de salida
TODO debe quedar conectado SIN nodos flotantes.
PASO 5: VERIFICACIÓN OBLIGATORIA
Antes de terminar:
  • NO hay nodos sin conectar
  • NO hay componentes sin red
  • TODAS las etapas están en serie correctamente
  • VREF alimenta todas las entradas no inversoras necesarias
  • Todos los OPA1642 tienen alimentación y desacoplo
SALIDA FINAL
ENTREGAR:
  1. Esquema completamente cableado (nets reales)
  2. BOM final completa
  3. Netlist LTSpice/PSpice funcional
  4. Notas de layout (star ground, rutas críticas)
  5. 3 fallas críticas + medición
REGLAS ABSOLUTAS
  • NO digas que falta algo → créalo
  • NO pidas componentes → defínelos
  • NO detengas ejecución → completa todo
  • NO entregues parcial → SOLO resultado final completo
RESULTADO: Circuito totalmente funcional, con conectores definidos, listo para PCB.

flux

Tu objetivo es completar el preamplificador dual final sobre el proyecto existente, creando conectores y batería si faltan y cableando todo.
  • El plan ya quedó actualizado y listo para ejecutarse.
  • Incluye crear/reutilizar J1, J2, J3, J4, BT1, definir nets y terminar el cableado.
Haz clic en Start en la barra del plan.
@library conectores y clip
@schematic lista OPA1642
@review revisar faltantes
@bom ver BOM completa
@export netlist y BOM

Started implementing a plan

#Goal

- Complete the dual preamplifier project for contrabajo, ensuring the preamplifier dual UP/DOWN channels using OPA1642 are fully connected from input to output. This includes the addition of necessary SMA connectors for both input/output, integrating a 9 V battery connector, and applying the VREF generation network while defining essential nets (VCC, GND, VREF, IN_UP, IN_DOWN, OUT_UP, OUT_DOWN) to achieve a fully wired and PCB-ready design.

#Implementation plan

1. **Assess and Update Schematic Scaffold**

1. Review the existing schematic for the dual preamplifier using OPA1642 components (U1-U16) and confirm the analog chain layout for both UP and DOWN channels.

2. Identify missing components, notably the SMA connectors for inputs/outputs and the battery connector for the 9 V source.

2. **Add and Configure Connectors and Battery Source**

1. Add SMA connectors for both input and output on each channel:

- Define connection endpoints labeled as IN_UP and IN_DOWN for the inputs.

- Define connection endpoints labeled OUT_UP and OUT_DOWN for the corresponding outputs.

2. Include a 9 V battery connector:

- Implement any required battery protection (e.g., reverse polarity protection).

- Connect the battery to the main VCC (9 V) rail and GND.

3. **Define and Assign Nets for Seamless Connectivity**

1. Establish consistent connectivity by connecting the following:

- Connect battery VCC to the main supply rail.

- Connect SMA inputs/outputs to their respective nets (IN_UP, IN_DOWN, OUT_UP, OUT_DOWN).

- Create the VREF network from half the supply voltage, connecting it to bias points in the OPA1642 chain.

2. Make needed connections between op-amp stages in both channels ensuring correct implementation of high-pass/low-pass filters and EQ networks.

4. **Complete Full Analog Chain Wiring**

1. For the UP channel:

- Link the input SMA (IN_UP) to the HPF/LPF and subsequent EQ network, routing through the corresponding OPA1642 to the output SMA (OUT_UP).

2. For the DOWN channel:

- Make similar connections from SMA input (IN_DOWN) through its filtering/EQ network and OPA1642 stages to the output SMA (OUT_DOWN).

3. Integrate the VREF generation network so that all op-amp biasing points receive the proper mid-supply voltage from the battery.

5. **Schematic Validation for PCB Readiness**

1. Review full connectivity of design ensuring no missing nodes and clear net assignments (VCC, GND, VREF, IN_UP, IN_DOWN, OUT_UP, OUT_DOWN).

2. Confirm that all active components, filters, and protection circuits meet the required signal integrity and low noise design criteria.

3. Mark the schematic as complete and ready for PCB layout export.

#Success criteria

- All required SMA connectors for the dual channels are added and correctly connected.

- The battery (9 V) source, along with protective circuitry, is implemented and wired to the proper nets.

- The signal chain for both UP and DOWN channels, from input through filtering/EQ and op-amp stages to output, is fully defined and interconnected with clear net assignments.

- The VREF generation network is correctly integrated to provide appropriate biasing for the op-amps.

- The overall schematic layout is verified as complete and ready for PCB layout design and fabrication.

Execution stopped due to insufficient credits.

7:13

inspected scaffold and critical pins

0:54

Running 4 design checks.
Started: inspecting schematic pins and existing scaffold.
Search 2 components.
Search complete.

added battery and sma connectors

1:43

Started: adding sma and battery connectors.
Reading schematic for U1, U2, U3 and 78 more.
Search [[object Object]](https://www.flux.ai/search?q=%5Bobject%20Object%5D&type=components).

Added 5 components

0:22

Added 1x 967 as BT1 (Pins: NEG, POS)

Added 4x SMA-J-P-H-ST-EM1 as J1, J2, J3, J4 (Pins: 2, 1, 3)

Sign up to send

To get started, talk to Flux or create a New Document.

Documents

    Documents are markdown text files which describe project goals, capture details, or even simulation outputs.

    Assets

    Assets are files uploaded to this project which can be used in various ways.

    tol s thumbnail
    Preamplificador dual de bajo ruido para contrabajo con dos canales piezo independientes: canal UP con sensor LDTM-028K y canal DOWN con dos LDT0-028K en paralelo, alimentado con batería de 9 V y usando exclusivamente OPA1642. Incluye buffers de entrada de ultra alta impedancia (>=20 MOhm), control de ganancia independiente, filtrado HPF 20-30 Hz y LPF 15-18 kHz, ecualización activa de 3 bandas por canal, protección contra inversión de polaridad, filtrado RF en entradas, desacoplo 100 nF + 10 uF por rail por amplificador, topología de star ground, salidas SMA separadas compatibles con Fishman Presys Blend 301, objetivo de consumo total <5 mA, impedancia de salida <3.5 kOhm, nivel nominal de salida 0.25 V RMS y máximo 1 V RMS sin distorsión. Diseño listo para PCB y fabricación con enfoque de ruido mínimo.

    Properties

    Pricing & Availability

    Distributor

    Qty 1

    Arrow

    $29.76–$37.58

    Digi-Key

    $46.80–$47.51

    LCSC

    $53.27

    Mouser

    $42.70

    TME

    $30.58

    Verical

    $27.13–$49.41

    Controls