Douglas Self preamp from Linear Audio Vol. 5

Doug Self published a full-fledged preamp design in Volume 5. The design features a sophisticated tone control system. Tone controls have all but disappeared from commercial equipment as implementations were not always high enough quality. However, tone controls can help to improve the sound in your listening room allowing to slightly correct for speaker and room influences, or to slightly change a recording's tonality. Douglas embarked on a design with an absolutely transparent tone control system, and while he was at it, a very sophisticated excellently tracking volume control inspired by the legendary Peter Baxandall.

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High-octane Phono preamp

In Vol 6, Hannes Allmaier published his Peter Baxandall - inspired High Octane phono preamp. To facilitate building this preamp, Hannes gives some building tips and lists the Bill of Material. He also graceously provided the Gerber files for manufacturing the PC board for personal/study use. A picture of the ... Read more

A stepped-level control for Bruno Putzeys' Balanced Preamp project (Vol 5)

In Linear Audio Vol 5, Bruno Putzeys published an excellent article, called “The G Word”, explaining the importance of carefully treating the signal and its reference as a complementary pair of signals and how to prevent uncontrolled connections to (dirty) ground reference. Vol 5 came wih a free PCB to turn all theory into a practical project.

The level control with a linear potentiometer cleverly circumvents the non-linear properties of such a device. The implementation meant that at one extreme of the rotation, the gain of the preamp rises to infinity. Although in normal use that would not be an issue,... Read more