AES E-Library

AES E-Library

Gray-Box Modeling of Guitar Amplifiers

Document Thumbnail

Musical distortion circuits, especially guitar amplifiers, have been the subject of virtual analog modeling for years. There exists two main modeling approaches: white-box modeling, where the internal properties are fully known, and gray-box modeling, where only the input and output are available. This work proposes a gray-box modeling approach for analog guitar amplifiers using iterative optimization to adjust the parameters of a block-based model. The only assumption made about the reference system is its basic structure. The digital model is an extended Wiener–Hammerstein model consisting of a linear time-invariant (LTI) block, a nonlinear block with a nonlinear mapping function, and another LTI block connected in series. The model is adapted in two steps: first the filters are measured, and then the parameters for the nonlinear part of the digital model are optimized with the Levenberg–Marquardt method to minimize a cost-function describing the error between the digital model and the analog reference system. A small number of guitar amplifiers were modeled, the adapted model was evaluated with objective scores, and a listening test was performed to rate its quality.

Authors:
Affiliation:
JAES Volume 66 Issue 12 pp. 1006-1015; December 2018
Publication Date:
Permalink: http://www.aes.org/e-lib/browse.cfm?elib=19874

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

E-Library Location:

DOI:

Start a discussion about this paper!


AES - Audio Engineering Society