dibsmjf

Just a quick post, I have sustain!!! Found a split in my first coil, unwrapped a loop of wire of the coil and soldered it up and it only flippin works! Just got the coil sat on top of the neck humbucker, normal and harmonic mode seem to work ok. Only had a little play with it, off out into the sunshine now but totally stoked that it works, can't wait to get back and fiddle with it more! The distortion in the circuit is actually quite nice, with the gain pot connected to the 386 it goes from cleanish sustain to full on screaming feedback. Added extra trims to the preamp so I can adjust the input resistor and the source resistor, got a 10K trim in this position, seems to help with setting the bias on the J201, just working by ear and tweaking this and the drain resistor to get the best sound. More report and hopefully some pics and diagrams to come probably tomorrow, but just want to say a quick thanks to Pete, MRJ and everyone else who's put work into this project-THANKS!

Hi Pete, The jazzstrat looks interesting. How about a mechanism similar to a capo with an overcentre hinge and a screw to adjust the position is flips to? Got all the wiring finished in my SG today, I've gone for a seperate pre and poweramp connected by half an inch wires for power and signal, makes the assembly flexible so it will stow in the corner of the control cavity-will try and take some decent photos later on. I've gone back to the Fetzer style preamp, seems to work ok running into the amp and into a small speaker, quite a bit of distortion on the loudest notes. I've tried a few different transistors, including a random from a previous project which turned the whole lot into a fuzz. I've gone back the J201 at the moment, seems to give the best balance of higher output but not too much distortion. I'm not totally happy with it, but will see how it works with a new driver. Interested to hear you are putting some more of your circuits together, are you still thinking of putting these up for sale? Irrespective of whether I get my circuit working to my satisfaction, I would definitely be interested in purchasing a fireDrive. Assuming you build in a decent profit margin into the price, it would be good to give something back to you!

Hello, thought I'd add some of my experiences with this project so far... I originally wanted to add a sustainer to my main guitar, which is a H-S-H and thus a bit more complicated than Pete's Tele. To add to Pete's list of requirements, you need not only a working guitar, but also a guitar which you don't mind taking a bit of abuse and probably a few modifications. My Ibanez is my pride and joy, and so no work gets done on it without soft padding on the desk, masking the paintwork off and very careful soldering. If you're in a similar situation, this isn't the best situation for experimentation, as is required with this project. As a result I'm using a recently donated Epiphone SG, which I don't mind knocking lumps out of, dropping blobs of solder on and generally abusing. Continuing with the SG, when I got it all the electrics were basically shot, so new jack, pots, wiring and switch were needed, to keep things simple I decided to change from the standard SG two volume and two tone setup to a master volume and tone. This not only simplifies the wiring somewhat, it also frees up two control holes, which saves drilling all over the shop. A major part of the sustainer setup is the harmonic mode switch, essentially swapping the phase of the driver coil to get harmonic instead of fundamental sustain. Typically this has been done between the sustainer amp and the driver, but an equally valid way of doing it is between the bridge pickup and the switches. This has an added bonus, in that when the sustainer is off you have the bridge and neck pickups out of phase with each other. I know Pete is always banging on about keeping it simple to begin with, this switching would be part of the simple sustainer anyway, it's just a different place for it which opens up another non-sustainer possibility. In my SG I've got this hooked up to the push/pull tone pot. Next up, I fancied adding coil splitting for the two humbuckers, mainly because I had a spare push/pull pot kicking around... This was made slightly harder because the standard Epi pickups are only 2 conductor, however you can adapt them for coil splitting by removing the tape round the coils, and splicing a wire into the link connecting the two coils together. When this wire is connected to ground by the push/pull pot, it grounds the first coil leaving just the other for a single coil-ish sound. For the bridge this is relatively simple, just grounding through the pot body to the main shielding ground, but the neck pickup needs another wire running back to the 4PDT. This is necessary so all the connections to the neck pickup are removed when the sustainer is on. I've got a very rough schematic of all this lot drawn up, when I finish it off and if it works I'll smarten it up and post it, someone might find it useful, I certainly found figuring out how to get the sustainer integrated into the guitar one of the harder bits to figure out.

Hello again, Not had much time recently to work on my sustainer, bit of a family disaster taking up most of my time recently. On the plus side, I did a pickup swap job for a friend last week, not expecting any payment, but to my surprise he gave me his old Epiphone SG to play with! It was in a bit of a sorry state, so spent the weekend removing the bits of finish still on it and gave it a simple danish oil finish. Ordered a new set of electronics, keeping the original pickups for now but everything else is new. Going to put together another coil tonight and then get back to the circuit whilst that dries out. I've drawn up a wiring diagram for the guitar based on the 4PDT switch from the Guitarnuts post so we'll see how it goes. I'm away over the weekend so hopefully I'll report back with updates next week.

Yea the driver was a tricky to do, I had two bits of card white glued to the top and bottom of the core to keep everything in place. It's a bit of a mess to be honest, but it was only intended to be a test piece. The core is not magnetised, I have a selection of small magnets to fit to the bottom of it, I'll give it a test with the amp over the weekend. I've been using a speaker to test the amps as I've been working along, and I've use the stereo outputs of my GT-8 to test the amp and driver that I previously made, I haven't even been inside the guitar yet. Many thanks for the help MRJ, I think I understand now how the preamp needs to go together and more importantly why. I'll work through your hints over the weekend and see how I get on. EDIT: Just been having a go at this preamp, using MRJ's instructions and referring to the Fetzer Revisited on ROG. Below is what I've come up with so far, and the original Fetzer layout from ROG: Ok so the input flows through the 34K input resistor which I assume attenuates the signal slightly and the 3M resistor to ground is what generate the high input impedance so as not to load the pickups. The input then goes to the gate of the J201. Meanwhile, the 9V power flows through the 100K trimpot to the drain of the J201, the trimpot is then adjusted to give 4.5V between the drain pin and I assume ground-is that right? The output is taken from between the timpot and the drain, the 22nF capacitor is to remove DC current from the output. Finally, the source of the J201 is connected to ground via a 22uF capacitor. This is the bit I'm not sure about, what function does this cap serve? Also, the Fetzer has a 1.5K resistor in parallel with the cap, what does this do? As I understand it, by applying a current to the gate the transistor then allows a larger current to flow through it in proportion to the input current. When the transistor is biased to 4.5V this becomes sort of the base voltage for the transistor, so when we feed in an input, this causes the voltage to change up and down from 4.5V. The output cap removes the steady 4.5V because it blocks DC, leaving only the amplified AC. Does this make any sort of sense? dibsmjf

Thanks for having a look at it MRJ, now I look at it I see what you mean, I had the bias pot in the wrong place relative to the JFET-typical! I've ordered some new J201s along with a few other bits and pieces, so I'll come back to the preamp and hopefully get it sorted soon. As I mentioned above, I've changed my setup to a separate preamp and poweramp, which will hopefully make things easier to fit into my guitar and gives me the option to easily change/upgrade the preamp in the future. You're absolutely right (again!) Pete, my idea of using the distortion as a preamp was a bit of a bad one, the more I thought about it and your points the worse it became! It did work quite well as a clean boost but the circuit board was much bigger than I thought it was, so out with that idea. On the plus side just got my poweramp working well, based on the 386 suggested circuits but squished up loads so it will fit on an 8 by 9 perfboard as shown below: And here's a pic of the finished board, along with my second driver effort: Apologies for the terrible pic, I've only got my mobile to snap with at the mo. The driver is basically a 60x4x4 steel core wrapped with wire, onto the bottom of which I'll stick some magnets once I've tried a few, I think it's fairly close in design to psw's but I haven't described it very well. I've been working on an idea for handling the switching with a strat-type guitar, which disconnects the output and ground of the 5way, re-routes the 2 outputs and ground of my bridge humbucker from the 5way and routes it to the preamp & volume pot and applies power to the pre and poweramps. When the switch is off, the preamp is disconnected from the rest of the guitar, which operates as normally. This will require either 2 3PDTs or my prefered 6PDT open rotary which I've used before-a PITA to wire up, but more solid and reliable than a toggle in my opinion. The upshot of this switch is to disconnect the neck and middle pups and the 5way from the circuit entirely (ie signal & ground) which should cut down on interference I hope. If it all works like I have drawn it out, this offers the possibility of a fairly simple addition of a sustainer to most guitars, the only change to the guitar's wiring is tapping into the connection from the bridge pup to the 5way switch. Any thoughts? dibsmjf

Well I put my circuit together over the past few nights, the 386 section (from column 13 onwards) works as laid out above, I did make it up slightly differently so might update it and repost it if anyone's interested, if there's demand I'll do a stripboard version too although I probably won't build it to test. Not sure what happened with the Tillman, whenever I connected it up to the amp, I just got a horrible buzzing sound. However this may not matter, as I have had a different idea about how to go about this. I think I will split up the preamp and poweramp sections when they are installed in the guitar, with the poweramp going underneath the neck humbucker with short leads running up to the driver. My big idea is with the preamp, instead of using a custom made circuit, I have an old Danelectro distortion pedal at home, which from memory is all SMD and has a very small circuit board. So the plan is to gut this pedal, and use it as a preamp ie with the gain turned all the way down, this also has an advantage of having a built in tone control, which may be useful for boosting the treble to get better drive with the higher strings. As I was running over this in my head last night, I remembered Pete you were talking about implementing an electronic switching system so to use tiny SMD switches instead of toggles. Well, the Danelectro has electronic switching built in, so that effectively takes care of the preamp power, it also has an LED power indicator, which is switched on and off with the effect. Whilst this could be useful for indicating the power status of the sustainer, a possibly more important use is supplying power through the guitar to the remote poweramp section. I'd imagine it has a current limiting resistor (almost certainly SMD) to drive the LED, if I could find this and bypass it I'd have a switchable 9V power output to run to the amp, and I could run a status LED from here. The switch from the pedal could be replaced with any type of SMD switch which could be mounted anywhere, which is important to me as I'd like to keep my guitar as standard looking as possible. All of this is total theory at the moment, I was not at home last night when I came up with all of this so I couldn't check the pedal in question, but it seems to me like it might have some serious mileage in it. I did also have wild ideas of using a compressor pedal instead of a distortion as the donor for the circuit, which would give a form of AGC quite easily... I also made a start on my new driver, using some 4mmx4mm rod cut into 60mm lengths, based on Pete's Blueteleful driver design, potted with a mixture of white glue and super glue at the end to hold everything in place. It's currently drying off, when I left it things seemed ok, apart from the sides of the coil coming away from the bar, ie forming an oval around the straight core-will these air gaps matter, should I try and stick the coil to the core? I'll try and get some pics of my driver and amp up tonight, and hopefully some more progress on the distortion pedal circuit. dibsmjf

Thanks for the advice Pete, made a start tonight drawing out the circuit on some perfboard, I did initially start laying it out on stripboard, but then I realised I didn't have a piece of stripboard big enough to fit it on, so perf it was. Yea the driver I made was pretty weak, had to really crank up the juice going into in order to get it to sustain, I think it was going into harmonic mode as well based on listening to other people's samples. I also had tonnes of feedback if I moved it anywhere up past the 15th fret, I imagine this is because the shield of the neck pup is still connected even when only the bridge is selected (H-S-H with 5way). I've done quite a bit of work before with 5way super switches, I'm pretty sure it will be fairly easy with one of these to set things up so that each pickup is totally disconnected when it is not selected by the switch, as it can switch more poles than a standard switch. Hopefully I'll get the board made up by the weekend, I've got guitars with HB and SC pups so I'll report back on how it responds. It seems to me fairly similar to the Fetzer in that they both use JFETs, if i get the first one working ok I might have a go at replacing some of the resistors with trimmers to try and get more gain out of it, any pointers which I should go for? Pete the Blueteleful is absolutely stunning, all the parts just go together so well, the wiring looks top notch and most importantly it's totally finished and pro looking-something my mods never end up being! The last one of which was a HSS strat with individually selected pups, coil tap on the HB, phase switching on all 3 AND series/parallel switching. Now that was a mess, I ended up with 4 DPDT toggles, 3 DPDT sliders and a 7PDT rotary to do the series parallel switching which was comprised of a 6PDT with an extra 1PDT slaved off it-what a mare! Back on topic, whereabouts is the voting for the GOTM, I found the July, Aug and Sept threads but couldn't see the Blueteleful-any chance of a link? Cheers, dibsmjf

Hi everyone, Been a bit of a longtime lurker, I think I first found this thread when it was around 100 pages long, I see things have moved on considerably since then! Having recently rediscovered it, I decided it was time to join in! So far I've made a rough driver with a humbucker magnet and some 0.19mm wire, hooked up to dismembered computer speakers, just to confirm to myself that it does actually work! A couple of nights ago I made a start on a Felter/Ruby on perfboard, but having since read through a lot of the later posts there seems to be a feeling that this isn't a particularly good combination. Had a bit of a trawl about for simple preamps when i remembered about a FET preamp in a cable I'd seen ages ago, here, which also has a normal version here. As this has been designed with audio quality in mind, maybe it will be a better (cleaner) preamp than the Fetzer. To this end, I've knocked together a quick layout combining it with the Ruby: Only just finished doing it, it's my first layout and obviously haven't built it yet, any comments? Edit: The 3 red pads are where the volume pot connects to the board