Resources

The following resources are a collection of freely available schematics created by Deane Jensen of Jensen Transformers, whose work helped shape high-performance audio in studios, broadcasting, and live sound. These designs are shared in honour of his legacy but as an open invitation to build, experiment, repair, and enhance the tools we use to produce music. His approach was practical and rooted in real-world engineering, and it continues to align with the best practices documented by the Audio Engineering Society (AES).

At their core, these schematics rely on balanced signal transmission and transformer coupling as primary means to address noise and signal integrity. Balanced lines employ differential signalling to reject interference, while transformers provide galvanic isolation to prevent ground loops, which are one of the most common sources of hum. They also offer precise impedance matching, controlled level shifting, DC isolation, and inherently symmetrical operation, all of which contribute to reliable, predictable performance in challenging environments. These are not mere stylistic choices but proven engineering methods that continue to perform well in a host of conditions.

These schematics are shared for use. Build them, modify them, improve them, or use them to repair what you already have. This is practical knowledge, freely passed on, in the spirit of those who learn by doing and aim to leave things better than they found them.

If you need assistance, it’s here. Take the designs, make them your own, and keep good engineering moving forward.