I'm excited to let people know about a talk being presented by a visitor on Wednesday, Sept 25, at 5pm, in the PLOrk studio (Effron Music Building). Kurt James Werner will be visiting and talking about his music and giving an introduction to the techniques he uses to model analog audio circuits digitally, Wave Digital Filters (WDF). All are welcome, it's FREE and open to the public. Hope to see you there! Jeff Snyder Director of Electronic Music Princeton University --- Details below: WHEN: Wednesday, Sept 25 5pm-7pm WHERE: PLOrk Studio on the Forum Level of the Effron Music Building (in the new Lewis Arts Complex) FREE and open to the public Title: Virtual Analog Modeling using Wave Digital Filters: a Tutorial Introduction Bio: Dr. Kurt James Werner conducts research related to virtual analog (especially Wave Digital Filters), the history of music technology, 1-bit music, computer modeling of circuit-bent instruments, & sound synthesis more broadly. As part of his Ph.D. in Computer-Based Music Theory and Acoustics from Stanford University's Center for Computer Research in Music and Acoustics (CCRMA), he wrote a doctoral dissertation “Virtual Analog Modeling of Audio Circuitry Using Wave Digital Filters.” This greatly expanded the class of circuits that can be modeled using the Wave Digital Filter approach, using the classic Roland TR-808 bass drum circuit as a case study. As a researcher, he has also worked on the history of analog drum machine circuits. As a composer, his music references elements of chiptunes, musique concrète, circuit bending, algorithmic/generative composition, & breakbeat. As a Lecturer in Audio, he was based out of the Sonic Arts Research Centre (SARC) of Queen's University Belfast for several years, and will soon (in 1 week!) start a new position as a Research Engineer at iZotope, Inc. in Cambridge, MA. Synopsis: In this tutorial, the basics of the "Wave Digital Filter" (WDF) approach to virtual analog modeling will be presented. The WDF concept was introduced as a generic digital filter design technique by Alfred Fettweis in the 1970s, and has been picked up slowly by the audio DSP community starting in the early 2000s. Today, WDFs are capable of modeling audio circuits with complex topologies (bridges, feedback, &c.) and multiple nonlinearities (diodes, transistors, &c.) and can be considered one of the main approaches to modeling audio circuits in software. A wide variety of audio circuits have been successfully modeled, including the Roland TR-808 bass drum, amplifier tone stacks, Ibanez Tube Screamer, OTA-based state variable filters, tone boosters, the Electro-Harmonix Big Muff Pi, the Korg MS-50 VCF, & Fender and Mesa Boogie preamplifiers. The main focus of the talk will be the basic mathematical concepts that underpin WDF modeling and tutorial examples, including a simple RC lowpass filter & the Hammond organ vibrato/chorus circuit. Some progress on modeling a mysterious analog filter from the Experimental Music Studios (EMS) of the University of Illinois at Urbana-Champaign (UIUC) will also be presented. -- Composer, musician, instrument designer scattershot.org http://scattershot.org * @snyderphonics