Thank You Shadow Wolf. Because of the trolling (actually a single member, also a member here) I help people who require it by email (available in my profile) and this is much more productive. I've helped two in the last week, one successful sending this last night:
by the way..i did manage to get the sustainer hooked up into the ibanez a while back..it actually f*****g worked..i was AMAZED..not that your design worked..that I...ME..could actually build such a device hehe. If I havent said it enuf man..THANK YOU =D
The other, like so many, just a simple error and misunderstanding. He sent me pics and even video of tests, used the F/R, rewound a single coil, on a guitar much like this strat... but didn't do a couple of things that ensured that it didn't work but I believe will in the very near future. Hear is his driver...
As the many others illustrated, the lower part of the bobbin is blocked off, 3mm space at the top is left to wind on, the coil is fairly well glued all through with PVA. He built the F/R to spec and seemed to be working, but it didn't work....it took a bit of back and forth till I got to actually see the driver like this...
One reason was that he made the very common error of jumping directly to the installation stage before successfully getting the thing to work. It is always best to build the circuit and test it with a speaker, then test it with the driver (taking wires directly from the bridge pickup and holding the driver above the strings well away from the pickups above the neck), ensuring that the middle or any other pickup coil is completely disconnected from the circuit (both ground and hot, so not just simply de-selected). Other pickups can be accommodated with a 4pdt bypass on/off switch. Assuming that it will work before it does work is never a good thing but on a typical strat, it is a lot of work to take the scratch plate off and when you do, how are you going to test it while still having a working guitar?
This would have made things easier, but was not the actual cause of the problem. The middle pickup could be easily disconnected but the driver looks ok, should be getting something?
No, because he thought it would be a good idea to make a more 'blade' type thing with an internal magnet...this is not strictly the design. His magnet then looks like this...
Not good and took a few emails and tests till this was revealed. The magnet was on the bottom flat, but now inside on its side with the north/south not going through the core but to either side....clearly not what we want (looks neat, might even work with an HB type magnet that is N/S along the edge, but not this one)...if not for this, and judging by the video he sent, it would easily have worked and I expect a similar email to last nights very soon.
On the circuit, it's not one I personally have used, but many have including these two with success. Unlike my 'troll' i don't have a problem with the LM386 as a simple amp for the project and beginners. It is still the heart inside the Ebow for instance, and I still use them in my own guitar...though i have used many amps over the years and have options. The Fetzer part is designed for "tone" (ie distortion) which is not the most appropriate for the project...but really the point of the 'preamp' is almost entirely simply to prevent loading on the pickup with the driver connected and the fetzer will do that and again, has been successful.
The RoG circuits though are slightly too basic. A 10uF cap added between pins 1 and 8 in series with the trim gain pot there helps to keep things stable and stop internal oscillation (squeal) at high gains for instance (such things are clear in the data sheet for the chip). Generally I use a 100uF output cap instead of the 220uF cap in the circuit there, this gives the circuit a more high end bias and so moderates the low string response (the thicker, slower strings are a little too responsive) while helping drive the high strings (with less metal in them and faster speed, harder to drive physically).
Another thing to do is to be sure to test all this with a battery and ensure that it is good. Many will try using a power pack, but this can give false results...the voltage may be 9 volts, but the current could be more than a real battery will be able to provide. Also, such power often will contain noise that can get into the ground and cause problems, unless you are intending to plug the guitar into the wall when done, use a battery. On that also with a strat and similar, you are going to need to change it, so in the main cavity where you may need to remove all the strings is not likely the best place...many have squeezed it into the trem cavity. I personally think the trem is a great addition to a sustainer guitar, but some have got a battery in there and still use it ok.
One other problem that comes up on guitars like this and the guy I'm helping here has been finding, the driver is the heart of this thing and you should get some response with any simple amplifier circuit if it works (tested with a speaker right), but the source pickup is also important. A low quality SC pup, especially in a poorly shielded strat or with wires hanging out while testing tends to pick up a bit of noise, especially in a testing environment. Any noise will be amplified and transmitted by the driver and do nothing to drive the strings and may even be detrimental. An HB is ideal, but my first sustainer was such a guitar, so it can work, just be aware and keep noise to a minimum and ensure all other pups are completely disconnected not just 'de-selected' as with the pickup selector that keeps the ground hard wired.
Alright, so these are the general mistakes to avoid and such and my contact address is there for most to see. Most mistakes are fairly simple but can be hard to understand or identify unless everything is disclosed and clear pictures like the above are necessary. The driver above is being rebuilt as it was constructed, poles and magnet below and there are lots of pics about of such conversions....no need to move the magnet or to have a rail type typical of what I tend to use.
As I say, most productivity can be made with direct non public email conversation and many people have become friends and many others have simply built the thing and it worked and just dropped by to thank me. My Telecaster is still going strong with a sustainer very similar to this basic model and useful, I still work on guitars and just gone back to a strat with some neat writing and features (but no sustainer) and in the infancy stages of putting together a home studio. I have no doubt that the sustainer will make some appearance in the recording environment, but remember it is just an effect, a unique and fascinating thing, but not hte be all and end all of guitar technology!
Hope this helps a bit and others who may be contemplating this and again, contact direct by email is better than muddying up the forums while ironing things out and inadvertently giving the impression that there are problems with the project when it may just be a simple 'good idea' gone wrong, like mounting the magnet sideways...oh, and good luck! Pete