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Cycfi

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Cycfi last won the day on May 15 2014

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  1. Hi Carl, My pleasure, Carl. This forum is special. This is where my journey started. Thank you very much for all your support and enthusiasm! Actually, I hesitated a bit, fearing my reply might be construed as self serving advertising. I've been less active in forums since we started going commercial (but just enough to sustain R&D), although we're still 100% open source, with all the designs shared in GitHub for everyone. Some forums have very strict guidelines against sharing links. I would certainly love to post updates every once in a while if you allow me to (e.g. the Infinity Project).
  2. Hi Psychonaught, Oh absolutely! See http://www.cycfi.com/projects/nu-series/ The Nu is the descendant of this project.
  3. Hello Y'all, The Infinity Project... We've been talking about it here. Here are my thoughts on how the project will proceed, the goals and objectives, the implementation strategy, how it compares to current systems, etc. http://www.cycfi.com/2014/06/the-infinity-project/
  4. LOL. I know exactly what you mean. I have this hall of shame drawer full of non-working junk. I'll post that sometime just for laughs :-) Anyway, I think I'll stick with what I have now. One variable. Refine. Rinse Repeat. I think I'm closer now than ever before.
  5. Thanks for the links. I just recall now that I've had these links before. Man, I'm getting old! The one who wrote that (Elantric) even sent me the same links sometime ago while developing the Neo pickups. I see now that this rolloff is the main reason why people are complaining about the roland pickups' sound when sent directly to a multichannel audio interface. Now that *IS* interesting. Have anyone tried that here? Talk about feedback! That's feedback gone wild. Perhaps some filtering will tame that feedback. I wonder how well it behaves though, especially when playing clean with lightly played and long sustained notes (none of that in the video). That demo sounds like an uncontrollable mess, with lots of noise and some overpowering microphonic feedback.
  6. That makes sense. Thanks for the correction. I guess it's the same for the GK3. Are the low pass filters not bypassable? Are there schematics (or at least block diagrams) available? Do you know what the cutoff frequencies are? Exactly! I've been experimenting on driving the strings using various harmonically rich waveforms and the results are astounding! The string is a very resonant filter and passes only its fundamental frequency and its harmonics. It is a comb filter that adjusts to your playing. I'm excited to try more types of waveforms and even noises. I'll keep you guys informed. This is my holy grail and I am super excited about this! I'll need your support! It's an uphill battle trying to convince people to think beyond the 50's "Mojo", relic'd guitars, over-priced "boutique" pickups, etc. It's 2014 now and we're still locked in the past. Guitar players are super conservative but I'm pretty sure there's interest in high tech guitar and I want to be able to connect to them, such as in this forum.
  7. Thank you! Yes, I want to be able to use ordinary strings. That was a requirement from the very beginning. As for sustain dampening, no I won't do it the way Moog did. Moog, and the newer Vo-96 system uses pure acoustic synthesis and advertises zero post processing. In my opinion, that is not necessary. You can do a lot with post processing on individual strings including control of attack and decay. With post-processing, it's easy to chop an envelope to achieve the muted banjo like effect. That's what I intend to do. An advantage of this approach is that it is simpler, requires less power, and does not require special strings. You only need to get the string sustaining, plus introduce some harmonics along the way. There's so much potential in polyphonic processing that the Vo system shuns.
  8. Thanks. It's still a quirk with the latest VO-96 version.
  9. Each of our drivers are rectangular and covers at least two strings per string. That way we can track string bends (see the demo). After a few iterations, we found it to be the best configuration (so far). A push pull configuration made sense at one point and we tried it. There's this kind of tug of war pulling the string. Alas, it didn't work out quite well. Maybe we didn't have the proper configuration. Perhaps I'll try again. Here's a question for those who used the Vo system (Moog): On the Vo system, I notice that his drivers are small and round (like the Neos). I wonder how well it tracks string bends. Does it work well for bends? I only see it demoed on acoustic guitars. Here:
  10. Wow, I didn't think about that. Tell me more! What alignment would make it better? I only assumed that the magnetic pull is perpendicular to the string. Now that I think about it, it makes sense.
  11. All it should take is a little nudge. That's what I always say. I think current breed of sustainers are inefficient and use too much power. If you pull at the right moment with just the right amount of force, you can get something to oscillate indefinitely. That's the essence behind sympathetic resonance. With just the a little amount of force, at the right frequency, you can make a bridge collapse, for example. Why am I saying this? Well, to me, control is crucial. That's what I am developing right now. We've come a long way since last year when I started working on this. At first I tried an analog feedback system just like fernandez sustainer or sustainiac. It worked but was sooo unwieldy when you have to have 6 of them. Analog AGC does not cut it with 6 drivers. Why? Analysing the signals using a scope, I see that the phase is almost always wrong. Why? That's due to the delay between the driver and the pickup. You can use analog phase shifters to get the phase correct, but that will make it even more cumbersome. Because of this, you have to use brute force to get the string to oscillate, and that wastes too much power. That may be OK in a monophonic sustainer, but multiply that by 6! I've now abandoned the analog approach in favor of a digital approach with an MCU doing the phase and frequency locking and synthesising a waveform that's fed back to the driver. The MCU can do the phase corrections, analyse the envelope of the input and control just the right amount of signal to drive a string to oscillation. I can even make the driver sleep for a few millisecond intervals (output disabled), esp. with the heftier strings that are very easy to pull. That saves energy. The best part about the digital system is that I can feed any kind of waveform back as long as its coherent with the input. Recently, we've tried square, pulse, triangle and sawtooth. Wave tables would be cool, for example! How about samples of bow noises or wind blow noises? How about the human voice? Guitar or Piano samples? That might be cool. And, needless to say, there are no nasty squeals that plague analog feedback systems. It's just pure sympathetic resonance!
  12. It's certainly a great start. Very interested to see where this heads. Does the system rely on your hexaphonic pickup or can any pickup be used alongside your "driver"? I notice that there's still a little bit of superimposed overdiven signal in the sound (eg, 0:52 - 0:58 in your video). This was something that seemed to be completely unavoidable in the old DIY sustainer that a lot of us here at Project Guitar built years ago. There were many theories behind the cause of this at the time - proximity of the driver to the pickup, driver amp being overdriven, driver being overdriven, low-tech of driver circuitry, induction/coupling of driver signal back into sensing pickup etc - but no real fixes. Is one of the areas of your project to tackle this "interference" in the sustained signal and make it operate as cleanly as possible? The hour or so I spent playing a Moog guitar at a store about a year ago seemed to imply it was possible to do completely clean sustain. Yes, it requires the Neo polyphonic pickups. I'm not sure what other way to do it. You'll need a polyphonic pickup to have polyphonic sustain. The Roland GK3 maybe? But the Roland divided pickups are passive with a very weak signal. Yes, there is the "overdiven" signal. And yes it can be eliminated. As I said, in that demo, the controls are bypassed. In that demo, the drivers are actually driven by a synthesized square wave and a class D driver using PWM! It's not an analog feedback system. It's a phase and frequency locked loop with an MCU controlling what gets fed back into the drivers. A square wave gives you that synthy sound. A sine or triangle wave gives you a more natural sound. Combinations of some odd and even harmonics gives you something in between (natural to synthy). There's also this issue of inductive coupling too, yes. Yet, the hex pickups have a very low susceptibility to such interference by orders of a magnitude. If I were to use a strat pickup, for example, the inductive coupling would have been maddening! That would mean though that the system might not be usable with other types of pickups. I know that you can't use any other types of pickups with the Vo system too due to this interference. I still have to figure out that one. At any rate, note that the drivers and pickups are fully exposed. It may be plausible to constrain the magnetic field of the drivers with some isolation (maybe mu-metal sheets).
  13. Exactly! That's similar to what was just discussed in the comments section in that link. Yes, that's why I want it open. I'm extremely stoked about this. I'm more excited than ever before!
  14. In that short demo, the MCU controls are bypassed. The MCU should be able to control the harmonics of the driver to make it as natural or as synthetic as you want depending on how much injected harmonics you allow to feed into the strings. I'd love to feed it other sounds as well, like say, bow noises :-)
  15. Hi Y'all, I just posted a new project in this forum: It's the start of what I've been alluding to at the very start of this thread: an infinite sustain system. I'm VERY excited about this one. Like before, I would very much love to hear your thoughts and gather ideas while the project evolves!
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