Erik Runeson Posted March 1, 2007 Report Posted March 1, 2007 I'm playing around a bit trying to simulate different types of guitar tone controls using SwCAD/LTSpice. I'm interested in the frequency response of anything from dead simple (Volume + Tone), to really complex (Varitone, TBX). Trying to find some ideas on how to mod my guitars. I've made some successful simulation of tube amps using the models from Duncan Amps, so I'm familiar with the basics. On an amp simulation, the impedance of the input signal is not very important since the amp has a very high imput impedance. However, with passive guitar tone controls, the impedance plays a big part. If the impedance is not correct, the result will be way off. Has anyone made such simulations? I'd be very happy if you could give me some hints! Quote
unklmickey Posted March 2, 2007 Report Posted March 2, 2007 it's probably been done here before, but if you can't find some help here, talk to these guys: http://guitarnuts2.proboards45.com/index.c...&user=johnh http://guitarnuts2.proboards45.com/index.c...user=channelman they've done some work in that area, and can recommend networks that will be decent models to sim a pickup. they've also run sims on guitar tone controls, treble bleed, affect of cable capacitance, etc. Quote
JohnH Posted March 3, 2007 Report Posted March 3, 2007 (edited) it's probably been done here before, but if you can't find some help here, talk to these guys: http://guitarnuts2.proboards45.com/index.c...&user=johnh http://guitarnuts2.proboards45.com/index.c...user=channelman they've done some work in that area, and can recommend networks that will be decent models to sim a pickup. they've also run sims on guitar tone controls, treble bleed, affect of cable capacitance, etc. Hi Erik and Unk - heres an example of a pSpice sim where we were checking out an idea for a bass cut tone control: http://guitarnuts2.proboards45.com/index.c...8913&page=2 THe pSpice is near the bottom of the page The pickup is represented as an AC source, which you set to sweep through the audio frequencies. Thats in series with an inductor and resistor, with a 0.2n cap to represent the pup coil capacitiance. Good values for single coils are 2.5H and 6k, and double that for Hbs. Then you model the guitar volume and tone controls as designed, and add the cable capacitance and amp input impedance. Cables are about 40pF per foot, so 0.8 to 1nf cable capacaitiance will model a 2'0 to 25' cable. Amp impedance is often about 1M. I hope that helps. Call in to GN2 to find more of these. John Edited March 3, 2007 by JohnH Quote
JohnH Posted March 3, 2007 Report Posted March 3, 2007 Further to the above: Heres a great article on the electrical characteristics of pickups: http://buildyourguitar.com/resources/lemme/ see also the table which is linked half way down, with values for a wide range of pups. John Quote
Erik Runeson Posted March 3, 2007 Author Report Posted March 3, 2007 Thanks a lot! This was exactly the kind of info I was looking for! Quote
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