Jbl N7000 Schematic [ Verified ]
| Block | Primary Function | Typical Components (generic) | |-------|-------------------|------------------------------| | Power Input & EMI Filter | Accepts 120 V / 240 V AC, provides common‑mode and differential filtering. | X‑caps, Y‑caps, common‑mode choke, MOV, fuses. | | Rectifier & Bulk Capacitor Bank | Converts AC to DC and stores energy for the high‑current demand of the amp. | Full‑wave bridge (Schottky or silicon), 4 kµF–10 kµF electrolytics, soft‑start circuit. | | DC‑DC Conversion (±V Rails) | Generates the ±48 V (or ±60 V) rails used by the Class‑D stage and supplies low‑voltage rails for logic. | Fly‑back or forward isolated converters, synchronous buck regulators, sense resistors, voltage‑feedback loops. | | Input Section (Analog / Digital) | Accepts line‑level analog, USB, and Bluetooth (via external module). Provides gain control, filtering, and level detection. | Op‑amp based pre‑amp (e.g., OPA1656), volume pot network, high‑pass/low‑pass filters, micro‑controller ADC front‑end. | | DSP / Control MCU | Performs crossover, EQ, limiter, and protection algorithms. Stores user settings and handles communication (e.g., Bluetooth, UART). | ARM Cortex‑M4 (or similar), DSP firmware, non‑volatile memory (SPI‑Flash), I²C/SPI peripherals. | | Class‑D Power Amplifier | Amplifies the processed signal to drive the 8‑inch woofer and 1‑inch tweeter. | Two‑channel half‑bridge topology, MOSFETs (e.g., IRF540N), gate drivers (IR2110 family), current‑sense amplifiers, bootstrap capacitors. | | Output Stage & Protection | Provides low‑impedance speaker outputs, monitors over‑current/over‑temperature, and implements safe‑shutdown. | Output LC low‑pass filters, sense resistors (0.1 Ω), fault detection comparators, crowbar/thermal shut‑off MOSFETs. | | User Interface | Front‑panel controls (volume knob, power button), status LEDs, and optional LCD. | Tactile switches, rotary encoder, LED drivers, MCU GPIOs. | | Power‑Management & Monitoring | Supervises supply rails, temperature sensors, and battery backup (if equipped). | Voltage supervisors, thermistors, I²C‑connected power‑monitor ICs (e.g., INA219). | | Mechanical & EMC Considerations | Ground planes, shielding, heat‑sink layout, and connector placement. | Copper pours, thermal vias, ferrite beads, shielding cans. |
Note: The exact component part numbers and values differ between the 120 V and 240 V variants, and between revision A and B of the board.
Signal Input (+) → L2 (0.30mH) → Midrange Output (+) ↓ C1 (3uF) → Attenuator Switch → L1 (0.20mH) → Tweeter Output (+) jbl n7000 schematic
Ground (-) is common for both outputs.
Wait—sharp-eyed engineers will notice something unusual. In most second-order crossovers, the high-pass uses a series capacitor followed by a shunt inductor to ground. The N7000 is different. It uses a series capacitor (C1) followed by a series inductor (L1). This configuration creates a second-order high-pass filter, but the inductor is in series with the load rather than shunting to ground. This is a deliberate JBL design choice to maintain phase coherence between the drivers at the 7,000 Hz crossover point. | Block | Primary Function | Typical Components
If you are troubleshooting a non-working N7000, here is your repair flowchart.
JBL no longer publishes service manuals for this product. However, high-resolution scans exist in vintage audio archives. Here are legitimate sources: Signal Input (+) → L2 (0
Warning: Avoid shady “paid schematic” websites. The N7000 design is public domain. No one should charge you for this 70-year-old circuit.