MiS

hmm... will try to keep it down Progress I finally made my coil. I didn't have any ferrite around (I'm on the lookout for some old disposed radios as apparently we can find ferrite core coils in the shortwave antennas) but I did it with a steel (seems like it) core. I got it from an old pickup (that had one little rod per string) so I figured I can't be entirely wrong. Unfortunately I don't have any magnets around so I took this huge magnet (from the same pickup) for testing purposes... The core is about 15mm tall, 5mm round. I wrapped around 300 turns of coil wire (0.2mm i believe) as per your suggestion. I skipped the glue part (just because I was eager to run a test and did not have any useable glue around) and, well, perhaps it's not tight enough. But anyways, I got it working! First I tried to feed it the guitar. It actually worked quite fine as a crude sustainer (I guess I am where you were 2 years ago? ) The only thing is that I have to keep the coil very close to the strings and it does not drive the string hard enough. I guess some adjustments in coil construction/amp circuit are in order... My second test was to drive it with a sine oscillator (and still keep a bit feedback of the guitar signal, of course). It works. I can go up to 3rd harmonic, the 4th is very weak. I would like to go higher, I guess adjusting the strength of the driving coil should improve the overtone reaching. Side note Just fooling around with magnetic feedback (is that what you call it?) when bringing the driver near active pickups makes great sounds. By varying guitar's volume and tone and the amount of feedback (though my mixer) and a little EQ made som beautifully ugly noises. I know I am not the only one playing with magnetic fields (Theremin come to mind) but I think I will use this technique on my upcoming show (this Saturday). The show will be recorded, so watch out. Haha! I like this term. Although there is nothing of aeolian in this but this is, in principle, what I am after. Actually, I am not interested in creating experimental sounds with this. Just going back to basics, pure intervals, harmonic series and the like. Also, a different approach to playing the instrument. I can code live and drive it to create beautiful algorhythmic music, reduce the CPU usage (right now my efx use about 70% CPU) and start doing some visuals with spare cycles If the sustainer can add to the vocabulary of the guitar, I may even be tempted to get back to playing more "conventionally". Keep it up On the other hand, I would like to know what is the amp you people are using to drive the sustainer? Is it the Fetzer-Ruby that I saw mentioned? Also, Pete, now that I've got my feet wet, I would like to start exploring the possibility of using the phase cancellation to control attack and note length. I believe I read you talk about this somewhere... Is it possible to have such control or am I dreaming in color? Anyways, thanks. I'm sure I will have more questions as I experiment. ./MiS

Absolutely. This is my intention. I am sorry for not having been more verbose from the start, I would have saved you a bit of typing as you explained some things of which I was aware already. But I thank you for your your input, your posts are very informative. So, a little background. I have been playing the guitar for almost 25 years. Classical (mostly 20th century music) and electric (a little jazz, a lot of blues, some rock/prog-rock type of thing). For the past 7 years I've played mainly free experimental improv using the guitar and the computer (as an fx rig, resynthesis tool, guitar induced synthesis, algorythmic improv tool etc). Lately I started exerimenting with live coding. In the past couple of years I also started foling around with alternative tuning systems based on natural harmonic series. I have started writing some pieces using only open strings and harmonics. So, today, the idea is to put together all these things. live coding and outputing specific frequencies to run the strings at the specific harmonics (and, optionally, perhaps running the guitar signal back into the computer for further processing but for now I would like to go back to basics). Some of my recent work is here So you mean, I have to modifiy the guitar as well? I would like to go even higher up the harminic series. Say, up to the 8th harmonic. Ok, so, I do need a feedback loop... I know that you have to hit the exact frequency. But in my set-up I mentioned in my first post I cannot get the string vibrate at all. I can feel the core in the coil vibrate but the strings remain silent (or, at least there's not enough movement to be audible). I used various oscillators sweep various ranges of frequencies to no avail. I think this is the element that would interest me the most, ATM. This is the kind of impractical nonsense that interests me ATM I am not interested in producing different tones. For that I use prepared guitar techniques and the computer. I want the pure string harmonics and vary the tuning of the guitar (well, not necessary on-the-fly) and thus be able to create all kinds of pure intervals in all kinds of configurations. hmm... this is interesting. So I need a feedback loop for this thing to be effective and track the frequency in order to properly drive the tone generator at the correct frequency. Right? BTW, I reiterate that I am not interested in controlling the spectrum through this technique. I dunno... I think the computer can keep track of a lot of informatino if provided with proper data... oh, BTW, I do not intend to use any fretted notes. For me, playing infinite drones = rocking out thanks. I did start experimenting but I came here because I am failing on some fundamental level. I may have >20 yrs experience in music but I'm a noob in electronics. thanks for the pointers, though. You have been very helpful. I will reevaluate my experiments and try to pick up on some of the ideas in this mega-thread. I will certainly report back and share what I have found/learned. I certainly welcome more ideas WRT to what I have expleained above. ./MiS

Hi all, i was just skimming through the pages (too many of them). I am not really interested in a sustainer, but the basic idea is the same. I want to drive strings with a coil but feed coil with an audio signal (in my case, from a computer) and make strings vibrate at the frequencies I choose. My theory is that I should be able to make the string move at different harmonic nodes, depending on the audio frequency I feed the coil. I built a simple amp (http://tangentsoft.net/audio/cmoy-tutorial/) but it is not enough (not even with my cheapo 25W guitar amp in series) to drive the strings. The signal leaks to pickups like hell (unless I place the coil far from PUs) but I can't get the strings to vibrate. I would appreciate any ideas, you seem to have been through all this. I am beginning to think that I probably need some kind of feedback mechanism but my goal is to control the frequencies (overtones) from the computer. Thanks.