RockTheory

Hi Dimitri, I have been waiting for the same thing as you, lol. Last I heard from mrjstudios was that he is working on one but had to put it on hold during college finals. That was about 2 weeks ago. Sit tight, it will happen sometime soon.. Hopefully.. -Brian

psw, I do understand that it's not as simple as reversing phase of the driver. Like I said, I did a lot of research . There are a few theories I want to work with, but I'm not so sure that it's just an electro-magnet with a constant pull. (However I will still check this method) As far as the Moog needing to plug in, I did not know of this-- however I have a hunch that it's probably converting the 110vac to something between 9-18vdc- Anything more than that on the cable and it could cause interference with the audio signal. I have been looking up amp designs but still nothing jumps out at me.. I will continue to look.. ps. I only use piezos as my output (DIN13, by Graphtech) to a Roland VG-99. Much more convenient, many more sounds. Thanks, -Brian

Hi everyone! I have made a bobbin-less driver and so far it works very well. I over-wound it slightly (about 9.5 ohms) but I didn't care as it's just a test on this design. Future designs will be a strict 8ohms. I have been doing a lot of research on the Moog guitar, and I think I have finally figured out how it works (At least, the damping). There is almost no information on the actual design so it was frustrating with dead end after dead end, but little bits and pieces here and there and now I have the idea.. I will post my results as soon as I find out!! (This may take a bit of work!) In order to continue testing with this new design, I need a better amp. Right now I am still using the Ruby amp and I know this is not a great choice. I don't know which amp to build though. Please link me to schematics! I need it to be very clean (no distortion) yet powerful and loud. Thanks! -Brian

Hah! Now I see! Your magnet is longer than your driver and coil, and that's what was throwing me off. With the tests I have run my magnets have been slightly smaller than the blade itself-- So I never gave it any thought.. Thanks!

psw, I completely understand what you mean about the .25 wire. I tried my first driver with .25 because it was all I had laying around at the time, and for testing purposes it was close enough. If I remember correctly you had said to use .2mm but it should never be thicker than .25mm. I took that as "not the best but it works", lol. My attempt at making a bobbin-less driver (with the same wire I had laying around, just for practice) actually came out pretty nice.. My issue was mainly, "How do I mount this?" - Yours looks as if it has a little plastic base on it. I will have to check out those mods to the F/R amp. Will probably be my next build. -Bri Edit: I'm not sure which mods you're suggesting.. I've gone back quite a bit and saw a few designs but I'm not sure which are correct.. ????

psw, Thanks for the reply. - Whichever amp is pictured on that page (http://runoffgroove.com/ruby.html, near the end) is what I built. - I did glue pot, as you instructed. - 30awg = 0.254mm, which is 0.004 bigger than you specify to be the largest to use. It does work but next build will be 32awg, which is 0.2032mm. - Didn't realize the multimeter has a little x1000 on the setting I was using. LOL! - Switching the 220uf cap with a 100uf cap works very well. - Reversing phase still has issues. (With new battery, only lower 2 strings work) After looking at your bobbin-less design, I've decided to give it a go. I have purchased about 5000ft. of 32awg wire to do a lot of testing on driver designs, and I am looking forward to it's arrival. I have a few questions about your bobbin-less driver, though. - What are the measurements on your blade? - What are the measurements on your magnet? (Where would I purchase one?) - What are you using as the base of the driver to secure it to the guitar? I don't have pictures or measurements of my driver as it is wrapped up in Electrical tape and tossed inside my guitar for use this weekend. I will be sure to document my next build with many photos ___________________ megadog, in reply to your question regarding piezo's: I have tried using the summed output of my piezo's as the input to my amp circuit. While it DOES work, the signal was very weak for the higher strings and strong for the lower strings. I'm sure there is a work-around but I'm not sure of what that would be. Hmm, does anyone have suggestions? I've thought for a while that piezo's would be the best way to drive this circuit-- but only if this problem can be overcome. (I am thinking a HPF.. and maybe a more powerful amp.) I will do more research and testing over the weekend. All input is welcome

Hello PSW, and everyone else. I have been inspired by this thread for about 3 weeks- and finally completed a sustainer for my 7 string. It works pretty decent for my first build, but I'm confused about a few things. I am not too handy when it comes to building or creating parts so my driver isn't the best looking, however as I said- it works.. well sort of.. Build: - Ruby Amp (http://runoffgroove.com/ruby.html; It came out great!) - Plexyglass top and bottom, steel blade core. (Not bad for my first try, but could be better) - I wound the driver with 30g wire (good enough start for first build) but my Multimeter says almost NO resistance. I checked a pickup coil (just to test meter) and it had about 9-10ohms resistance. I didn't understand why this was but decided to test the driver anyway. Results: - In normal mode it works but my Low-B string likes to dominate the "signal". - Reversing the phase of the driver, only the Low-B string works. Everything else seems to not be affected OR at times have less sustain (damping). - The thinner the string, the less sustain it has. Questions: - Are my results due to poor driver design? - Why do I have very little resistance but a driver full of wire? - Because of the "damping" effect I wonder, how would you modify this to act as a damper? (As the Moog guitar does) Would it be to have a constant "input" rather than your mag input? - Any suggestions on the next driver build? (How do I make it look and act professional?) Thanks!! -Brian