The primary function of the N7000 is to act as a high-pass filter, allowing only frequencies above 7 kHz to reach the ultra-high-frequency tweeter (such as the famous JBL 075 bullet tweeter).
"The N7000 dividing network provides a means of adding the 075 to existing high-quality two-way loudspeaker systems to obtain added brilliance in the high frequencies." — JBL Literature 5. Differences: N7000 vs. N8000 While similar, the N7000 and N8000 are not identical. 7,000 Hz crossover, ideal for 075/077. N8000: 8,000 Hz crossover.
primarily designed to add a ultra-high-frequency (UHF) driver, such as the
Investigations into vintage N7000s have shown that while capacitor types changed (from wax-filled to epoxy-filled), the core capacitor part #10460 (1.5 μ F) remained consistent.
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. jbl n7000 schematic
Connect the input of the N7000 to the "HF" terminals of your , N400 , or N1200 network.
The is a legendary frequency dividing crossover network engineered by James B. Lansing Sound, Inc. during the golden era of high-fidelity audio. Originally designed in the early 1960s, this passive, 2-way network is highly celebrated for adding ultra-high-frequency "brilliance" to classic horn-loaded systems. By crossing over at a remarkably high 7,000 Hz (7 kHz) , it seamlessly integrates the iconic JBL 075 ring radiator tweeter (or 077/2405) with mid-frequency compression drivers like the JBL 375. This configuration can be found in flagship speakers such as the monumental JBL Paragon and the JBL S8R system .
Popular online retailers such as are excellent sources for these components. For the best sound quality, many enthusiasts recommend using high-quality capacitors, such as paper-in-oil or polypropylene film types, for the series capacitor on the tweeter circuit, as this has a significant impact on sonic transparency.
systems (standard vintage JBL impedance), though some variants or modified units are used with 8-ohm drivers. Power Handling: Typically matched to the 2-way system's rating, often up to Circuit Design: The primary function of the N7000 is to
Moving beyond the power supply, the schematic reveals the heart of the amplifier’s sonic character: the input and driver stages. The N7000 utilizes a differential input stage, a common but effective topology for reducing noise and distortion. In the schematic, this appears as a pair of matched transistors. This configuration is vital for "Common Mode Rejection," which essentially means that any noise picked up by the cables or internal wiring is canceled out before the signal is amplified.
Understanding the schematic and electrical behavior of the N7000 is essential for maintaining, cloning, or restoring this iconic piece of audio history. Technical Specifications Overview
Disclaimer: Referencing original JBL service literature is always recommended before performing modifications. Lansing Heritage forums are a good source for schematic PDFs.
flowchart TD A[Amplifier Input Signal<br>Positive (+) & Negative (-)] --> B(Input Terminals<br>E1 (+) & E2 (-)); B --> CLow-Pass Filter Section<br>Inductor L2 in series; C --> D[Low-Frequency Driver Output<br>Terminals E5 (+) & E6 (-)]; B --> EHigh-Pass Filter Section; E --> FCapacitor C1 in series; F --> G[L-Pad Attenuator]; G --> H[High-Frequency Driver Output<br>Terminals E3 (+) & E4 (-)]; N8000 While similar, the N7000 and N8000 are not identical
Do you for the crossover? What tweeter are you pairing with this crossover?
If you are currently troubleshooting, could you let me know: Are you or doing a full rebuild ?
Do you have a specific repair question about your JBL N7000? Leave a comment below (on the original forum) or consult the technical library at The Lansing Heritage Foundation.
Thread: Rebuilding a JBL N7000. Possible? - LANSING HERITAGE
The JBL N7000 is a highly sought-after audio equipment, renowned for its exceptional sound quality and robust design. As a popular choice among audiophiles and music enthusiasts, understanding the intricacies of its internal components and circuitry can be a fascinating and rewarding experience. In this article, we'll delve into the world of electronics and explore the JBL N7000 schematic, providing valuable insights for DIY enthusiasts, electronics experts, and music lovers alike.