AES E-Library

AES E-Library

Digital Model of the Passive James/Baxandall Tonestack

Document Thumbnail

E. J. James described a two-knob tone control in 1949 with easily selectable boost/cut depths as well as cutoff frequencies. This design was later popularized by P. J. Baxandall to provide negative feedback in active circuits, and was subsequently popular in many high-end amplifiers. Here, the authors analyzed the circuit in the s-domain, preserving parametric control of bass and treble potentiometer values. Poles and zeros were found using Ferrariā€™s solution to a quartic equation, followed by bilinear transformation to the z-domain, and finally lumping into second-order sections to produce a computationally efficient and faithful emulation of this classic tonestack.

AES Convention: eBrief:
Publication Date:

Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!

This paper costs $33 for non-members and is free for AES members and E-Library subscribers.

Learn more about the AES E-Library

The Engineering Briefs at this Convention were selected on the basis of a submitted synopsis, ensuring that they are of interest to AES members, and are not overly commercial. These briefs have been reproduced from the authors' advance manuscripts, without editing, corrections, or consideration by the Review Board. The AES takes no responsibility for their contents. Paper copies are not available, but any member can freely access these briefs. Members are encouraged to provide comments that enhance their usefulness.

Start a discussion about this paper!

AES - Audio Engineering Society