Electric guitar mod (theory) - Page 1
Forum section: electronics / projects

author: Deutoplasm
author_rank: Contributor
timestamp: June 11, 2012, 03:25:11 am
content: If you were to couple a small ceramic capacitor to the base of each string, having the output waveforms tied to the input of a summing amplifier. Or, perhaps, have the output from the capacitors used as a positive feedback signal to the actual magnetic pickups output. How would this affect the sound of the guitar? Maybe some interesting sustain effects could be achieved.

author: IanB
author_rank: Super Contributor
timestamp: June 11, 2012, 03:47:37 am
content: How would you get an electrical output signal from the string?

author: Deutoplasm
author_rank: Contributor
timestamp: June 11, 2012, 03:55:54 am
content: I would get the output from the Piezoelectric effect of vibration on ceramic capacitors. Apparently, ceramic caps will vibrate when signals of appropriate frequency and amplitude are applied. Alternatively, if vibration is applied to the cap, then it should have a measurable output signal. this is what I want to use to manipulate the signal before entering the amplifier (if possible). Just wondering what effects could be made.

author: IanB
author_rank: Super Contributor
timestamp: June 11, 2012, 04:03:53 am
content: I'm not sure. Time to stop wondering and start experimenting!

author: Deutoplasm
author_rank: Contributor
timestamp: June 11, 2012, 04:09:45 am
content: Roger that. I'll start desoldering some caps and start rigging up a jig to do some tests. I cant find any usable data online as to the actual voltages that can be generated this way, so maybe I'll get some groundbreaking stuff going on!

author: Deutoplasm
author_rank: Contributor
timestamp: June 11, 2012, 04:57:18 am
content: I guess tiny surface mount caps are deceptively difficult to handle. burned my thumb a bit and my old guitar string broke and pop'd my face. I think I'd better do this when i'm not spazzy on coffee at 1AM.

author: T4P
author_rank: Super Contributor
timestamp: June 11, 2012, 07:18:40 am
content: You might as well put an actual piezo instead

author: DrGeoff
author_rank: Frequent Contributor
timestamp: June 11, 2012, 08:31:17 am
content: Yeah, I was wondering why you couldn't just use a bridge pickup, usually used on acoustic guitars and use piezoelectic sensors.However you will need active electronics, probably in the guitar, to do anything with it. Driving the regular pickup coil to have any effect on the strings (I'm assuming you are not using this as a pickup, but rather trying to couple the signal back to the strings using it) will require an amplifier and driver, but I doubt that it will be worth the hassle. Just rub the strings against the drummer's cymbal with the amp cranked up, it will drive everyone crazy!

author: T4P
author_rank: Super Contributor
timestamp: June 11, 2012, 11:35:32 am
content: I have my own "active" electronics in my guitar along with a batterySpeaking of off-the-shelf overly pricey electronics from EMG, they have a battery door in those guitars that come with EMG pickups ( still ... 2000$, i would rather buy a DSOX3000 )

author: Deutoplasm
author_rank: Contributor
timestamp: June 11, 2012, 06:00:52 pm
content: Honesty, I just thought it would be cool to exploit the piezo effects of ceramic caps. I just recently found out they were subject to such a thing. I have an electric guitar with crummy pickups. I want to try coupling the output voltage of the vibrating ceramic caps with the output of the actual pickups to produce wonkey effects. Really, i'm just playing around and learning about all the interesting relationships between this and that. Not practical, but certainly fun! (except for the burnt thumbs and string slapped face!) This tinkering might get me the X-prize for badassed component flaw exploitation!

author: T4P
author_rank: Super Contributor
timestamp: June 11, 2012, 06:14:40 pm
content: The more packed it is the more the piezoelectrical effect of the caps, well actually you can't solder to a steel string ... you should solder to the bridge at the back instead, that's where the vibrations gets most intenseWell i had exploited this very flaw to monitor the vibrations of a washing machine(How many times have you guys rigged a transistor as a active thermocouple?)