curtisa

A level translator needn't be complicated. This is about as simple as it gets: DC offset won't affect the audio signal as such. As far as the audio signal is concerned it is merely shifted up. Instead of going positive and negative around 0V it will now go "more positive" and "less postive" around a point midway between the two extremes. You will have to remove the offset after you've shifted it before passing the signal on to other processing stages. A series blocking capacitor on the output of the last shifted stage is the simplest way to do it. The value of this cap may have an impact on the signal and is dependent on the impedance of the surrounding circuitry, so leave room for experimentation. Dedicated switching ICs exist, but theyre not easy to come by and usually expensive as well. Don't forget that relays are used all the time for channel switching in guitar amps, mixers and the like, where small signals need to be handled gently to avoid excess noise. Simple techniques exist to minimise switching noise from relays and mechanical switches.

Regarding the switching there are two ways to deal with this. You essentially want the output wobbling either side of a non-zero reference to lift the negative swings of the signal away from the 0V cutoff point imposed by the CMOS gates: Introduce a DC offset of half your intended signal swing to the signals as they pass through each switching element - can be as simple as a couple of resistors and capacitors per switch. Run your CMOS chips from +/-5V and use a PNP transistor as a level translator to interface your logic 0/5V signal to -5V/+5V - very easy to do, but will require one translator for each switching element. Both solutions will require some more engineering on your part. CMOS switches aren't very robust and introduce obvious foibles with regards to switching voltages and the types of signals they can carry (as you've now found). Are small relays out of the question? Then you can mix and match switching supplies and audio signals as much as you like without having to worry about the interfacing problems. There's some useful info regarding using CMOS switches to control signals here. Your schematic shows the output being switched via a 4066 in series to achieve mute. A slightly more elegant way of achieving mute is to move this switching element to the input side of the opamp and use it to short (shunt) the signal to ground. Will this opamp being actually driving a speaker as is drawn?

No medical expert here, but I would think there are two main factors to the hazardous-ness of spraypaint - the airborne particles of vaporised paint while spraying and the fumes. Fumes can linger long after the paint has dried, and most products containing solvents will warn of headaches, dizziness, nausea etc when exposed in sufficient quantites. Maybe let the guitar air for a week or two in the shed away from indoors enclosed spaces to allow the fumes to finish dissipating? Do a search for the for the nitrocellulose lacquer MSDS to check for any safety warnings on the product with regards to ventilation while drying and drying times.

Hey Chris, I've got the templates that I created for a recessed 6-string FR Original that I documented I may be able to run the template bit around them to create copies in MDF if you don't mind paying for shipping from Australia? Although it might be more economical to see if someone closer to you like HuntinDoug would do you a set from the FR measurements on CNC?

Almost any manufacturer of a marketable product will put a disclaimer on their documentation that says something to the effect of, "We reserve the right to change or improve product specifications without giving notice to the end user". Chances are EMG just exercised their rights and changed their supplied/suggested tone cap without telling anyone. Nope. A different value tone cap will merely affect how much the treble is reduced when you wind down the tone pot (or more specifically at which frequency the highs start being attenuated). The bigger the value of the cap the lower the frequency at which the highs start being slugged.

ABM make a 12 string tune-o-matic bridge. Allparts stock it in chrome and gold. Not sure about the tailpiece though.

Nice work. Good to hear it's all up and running.

As usual, looking good Scott. Most of my smaller templates are constructed using a bunch of intersecting straight lines or curves made by taking advantage of the inherent diameter of the router bit or something larger like a holesaw. It makes it easy to build up a complex pattern like psikoT has, and create a master template from it with the router fitted with an inverted pattern bit. Standardising some of the more common templates in your builds helps too (eg humbucker cavities, single coil cavities, control cavities). The less one-off templates you have to make up the quicker you can get the job done.

This rather complicated looking contraption is what I use to drill the angled jack recess. First drill down about 30mm with a 3/4" forstner bit, and then switch to a 1/2" forstner for the remainder: ABM saddle mounting holes and control recesses: Carve depth set around the perimeter and pretty much done for the weekend. Ready to start the contouring:

The last time I visited a glaziers shop (+10 years ago at least) they had buckets full of them on the showroom floor for a few bucks per piece. That was long before my interest began in building guitars, and I can't remember what kind of sizes and thicknesses they had available that might be useful for this kind of work. Signwriters are a good suggestion. Might also be available at a boat builders' workshop too.

Out of the clamps and trimmed to size: Neck pocket jig time. A couple of strips of tape on each side reduce the route size by a bees' dick to ensure the neck is a snug fit: Couple of minutes with a sharp chisel to square up the corners: Moment of truth: Pickup cavities: Managed to land squarely on the pre-routed cable channels. Double depth cavity ledge is for providing clearance under the EMGs for the cable and connector. Seems a shame to hide the racing stripes with the pickups:

Thanks Scott. I made the mistake of not documenting Red Planet, and was then out of the workshop for a while on holiday followed by several large tool purchases which took a while to set up and tweak. Consequently this is the first build I've started in about 10 months. By all means. The idea wasn't mine to start with so I can't claim ownership of it. Have at it, says I. Perhaps one of those cheap digital angle-displaying rulers could be attached to the arm somehow? Trouble with that is I'd have to make up a table of measurements for the board and then have to constantly refer to it as I slotted to ensure I was cutting at the exact angle for every fret. I agree it's not the most super-accurate method of slotting a board, but it is cheap to build for a one-off board, and provided I go slowly and carefully I can just follow the printed layout underneath without thinking too much. Actually, with this jig I worry more about getting the fret-to-fret spacing accurate than I do about the slot angles. F-clamp serves a double-purpose of holding the end of the trussrod jig down and providing a stop for the router. The channel is long enough to cover bass rods plus the extension into the headstock. For a while I was able to get big offcuts of clear plexiglass from the recycling shop at our gabage disposal site for a pittance, but they've stopped stocking it (presumably no-one is throwing offcuts away anymore?). Might be available at a glaziers? Ta very muchly.

Been a while since I've done a work-in-progress, so here goes. Target specs: Body - Tasmanian blackwood/celery top pine/myrtle with Tas oak figured carved top Neck - Tas myrtle with blackwood veneer accents, jarrah fretboard Scale length - 26.5" to 25.5" Radius - 16" Trussrod - Allied Lutherie Tuners - Hipshot Griplock 4x3 Frets - Jumbo stainless steel Pickups - EMG 707 bridge, 607 neck Bridge - ABM independent saddles Electronics - 1x vol, 1 x 3-way toggle Always curious to try something new, so this time it's multiscale! Don't have access to a CNC so need to make a new jig to slot the fretboard. Saw the idea on anzlf.com, so whipped up my own using some scrap MDF, a pair or rare earth magnets and a spare allen bolt I had lying around. Print the fretboard onto a piece of paper at 1:1 scale, stick it to the blank and start sawing: After half an hour or so we end up with a slotted non-parallel board: Angled nut also calls for an compound angled scarf. Yet another new jig to cut the scarf. If I'd planned this better I would have made one of the two ramps repositionable to allow for different nut angles for other builds: Jumped ahead a bit here, but headstock is now on and shaped. Now the trusrod slot gets cut (jig-o-rama!). I much prefer to route the channel from the top instead of upside down on the router table with a fence, as I can see what the cut is looking like as I go: Trussrod nut access: Fretboard on: Body is made from two chunks of blackwood that were just a fraction too narrow to make a single blank. Rather than waste timber I bulked up the middle with some scraps of celery top pine and red myrtle stringers: All clamps on deck:

Solder one end to one of your pots and twist the other to your tailpiece or around the strings behind the nut. If the hum goes away while holding/playing the guitar normally your grey bridge ground wire is not making contact as it should be. Yep, good idea. Fixes for hums and buzzes are best evaluated with the instrument buttoned up as best as possible. Also a good idea to be positioned in such a way to avoid picking up external sources of interference such as computer monitors, laptop power supplies, light dimmers, TVs etc. Essentially, yes. The foil acts as a barrier to reduce external noise from being picked up by the instrument, and needs to be in contact with a grounded part of the guitar to be effective. Your pot cases and jack socket are already grounded via your wiring, so it's just a matter of screwing these components through the foil and onto the scratchplate. For additional shielding you can line the control cavity with the foil as well, provided it has some way of being in contact with the foil on the scratchplate when the guitar is re-assembled. You may be able to pick up a roll of self-adhesive copper or aluminium foil tape from an electronics hobby shop that can be applied to the back of the scratch plate around the area occupied by the pots and switches.

Yep, try the temporary wire as an experiment. The grey wire is likely to be bare inside the tailpiece post hole, and simply making contact to the post by being squeezed against it as it is inserted into the body. Maybe the wire has been pulled out accidentally or broken? If the temporary wire fixes things I reckon you may need to look closer at the bridge ground wire. Are you doing all your testing with the guitar dismantled? Don't forget that most guitars will buzz a little when plugged without you touching anything metallic. I also notice that you don't have any shielding under the scratchplate.

Your wiring looks OK, but you need that bridge ground wire (the grey wire with the blue tape on the end, 1st photo above) soldered to either of your pot cases. That should help with the hum.

Ahhhh, I understand now. Transferring the wiring from one guitar to the other as per the Ibz diagram minus the middle pickup will work, with the caveat that position 3 on your switch will give no sound. Your pickup selections will then be (1) bridge humbucker, (2) bridge coil tap, (3) no sound, (4) neck coil tap, and (5) neck humbucker. Excess hum that goes away when you touch something metallic is likely to be a missing ground to your bridge or the output jack wired back-to-front. Don't feel bad about the language barrier. Your English is far superior to my Dutch/French.

Maybe we're getting our proverbial and literal wires crossed. I'm assuming you're performing a swap of the existing Stagg pickups with your two new humbucker Ibanez pickups. The way I'm reading your query is that your Stagg humbuckers have 1 core + braid cables from each, and your Ibanez humbuckers are fitted with 2 core + braid cables. I'm also assuming you're leaving the rest of the wiring, switch and pots in the guitar untouched. If this is the case you simply take the two old pickups out of the guitar, install your two new Ibz pickups and wire them as I've described - braid of each pickup lead to ground and black (or white) to each volume pot middle lug with the unused wire from each pickup unterminated. At the end of the swap the wiring should look identical to the original with the exception of one spare wire from each pickup lead hanging in mid air. If you're wanting to wire up the guitar as per the Ibanez diagram minus the middle singlecoil the level of difficulty increases somewhat: your Stagg guitar has a 3-position 1-pole switch whereas the Ibz wiring requires a 5-position 2-pole switch. They are not directly interchangable. If you install the 5-position switch specified and wire it as per the Ibz diagram position 3 will give you no sound as the middle singlecoil is not installed. The Stagg appears to have 2x volume and 1x tone, whereas the Ibz wiring shows 1x master vol and 1x tone.

Extra wire on your Ibanez pickups is not a spare ground, but probably the coil tap conductor for coil splitting with the single coil for the typical out-of-phase-position-2-&-4-strat-type sound. Braid of the Ibanez pickups should be soldered to ground. Need to determine whether the Ibanez black or white wire is the correct one to use (not clear from the Ibanez diagram as they identify them as red and white). Easy test is to solder the white wire in place of your old pickup cabling and leave the black wire hanging unterminated. If it sounds good and doesn't hum leave it as-is. If it hums and/or has weak output swap the black for the white.

You can if you wish, but I reckon you're unlikely to find anything untoward with 3x brand new pots installed. I'm running out of ideas. If the wiring, battery volts and components are all OK the only things I can think of is that the low volume is an indication that the pickups are faulty (both pickups equally??), what you're plugging into is causing the output to appear low (maybe you're plugging into a mike input on your audio interface rather than a dedicated instrument input? Do you have an input attenuator accidentally engaged on the interface?), or it's just a characteristic of the pickups themselves. With one pickup volume full up, tone maxed out and the other pickup set to 0 you should be seeing over 300-400mV output going to your amp when playing moderately, which should be plenty loud. Adding the 2nd pickup will probably push the output to 500mV and over. I note that other EMG pickups (EMG81 or 85 for example, 3VAC) boast much higher output voltage than the LJ. Depending on which version datasheet you look at the LJ can either push out 0.8VAC or 2VAC. Maybe the set you have are working fine - they just have low-ish output?

The reason given by EMG for not grounding the strings has nothing to do with noise reduction. The claim by EMG is that it is a shock hazard due to you being grounded via the strings and then touching something ungrounded (or differently grounded than your instrument). Personally I'd want all exposed metal objects connected to electrical equipment to be at the same potential no matter what. If you're ungrounding your guitar in an attempt to avoid shocks from other connected equipment the potential for shock is still there and should be dealt with at the source. Shielding in the control cavity isn't mandatory with EMGs, but won't be detrimental to noise performance of the instrument either. Shielding the pickup cavities shouldn't be necessary and can be removed if you wish. You may need to get in touch with EMG and ask them what the difference is between the LG/SG and LJ/SJ pickups. It almost sounds like the LG set you have are active pickups with a high impedance output and don't use the low value pots normally supplied with active EMGs. It may be that the LG/SG set require higher value pots in order to develop the full output, or (hopefully not) require an additional preamp to boost the pickup outputs up to full throttle. Alpha make most of the world's supply of generic pots. You can probably pick them up at your local electronics DIY supply store for a fraction of the cost charged by Thomann. Unlikely. According to the LJ datasheet each pickup draws 80 microamps at 9V. In order to reduce the output so significantly at that current draw your battery box would have to be introducing an additonal 20-40Kohms of impedance at the battery terminals. If you want to verify, you can measure the battery voltage at the pickup and at the battery box. If the volts are practically the same then your makeshift terminals are working fine. You'd probably notice other problems first, such as distorted output or intermittent operation. Indeed. The EMG 18V mod is akin to going to your local and asking the landlord to pour you a 10oz beer in a 1 pint glass. The bigger glass is capable of holding more, but you've still got the same amount of beer to start with.

Battery known good? Distance of pickups to strings? Were the original pickups hot output to begin with? Are these particular EMGs marketed as a medium output set? Pots being the wrong value is a possibilty, but should be easy to confirm before ripping apart all your hard work. Shouldn't need to shield the battery compartment. Your shielding looks very thorough. You mention that you've run wires to all sections of shielding, but have you verified that they have continuity to the output jack shield tab (shielding needs to be grounded to be effective)? Maybe the remaining noise is external to your bass? Does the noise change in proximity to a computer monitor, fuorescent lights, lighting dimmers, laptop powerpack, fridge etc? Does the noise change when plugging in to an amp in a different room of your house? In a different house altogether? What about swapping to a different amp or guitar cable?

Electrically this should work. If you're unfamiliar with schematic diagrams maybe someone can convert my scratchings into a prettier line drawing. The 5-way switch is the same one linked to earlier. Phase/coil select switch is a normal on/on double pole mini toggle or push/pull switch mounted on the bridge volume pot. Coil cut switch is a normal on/on single pole mini toggle. Pickup wiring colour codes and tone capacitor values need filling in. http://i153.photobucket.com/albums/s222/ac1176/20140309_17585801_zpsa53adc22.jpg The numbered positions on the five way switch line up with your MS Paint sketch.

With switching requirements like you've listed I'd also suggest looking into per-pickup mini toggles over the toggles+5-way switch combination. If you consider that some of the more common switching operations you'll likely perform (eg, switching from bridge to neck, or neck to middle+bridge) will require you to operate two switches one after the other, you can achieve the same result using discrete mini toggles which simplifies design and wiring considerably. Prostheta's suggestion regarding weeding out the switching combos that you don't like or will never use will relax your requirements somewhat and make construction easier. If you're still keen on exploring your original idea, it is possible with a double-pole 5-way switch, and your required mini toggle switches with functions detailed at this page. Bridge pickup series/parallel/cut switch needs to be a (sometimes hard to find) double-pole on/on/on mini toggle. Bridge pickup phase reversal switch needs to be a double-pole on/on mini toggle. The neck pickup on/off function can be accomplished using a single-pole on-on mini toggle, although with your requirement that position 1 be "neck pickup off unless mini toggle switch on" could leave the user unwittingly switching to dead silence during a performance if they're not paying enough attention to the positions of the plethora of switches.

After only a minor* hiatus between albums, The Third Ending return with Three Word Title. 10 tracks of 4 blokes playing actual instruments, sounding very much exactly like that. Head on over to our website, iTunes, Amazon, Google Play, Bandcamp or whatever method of downloading you fancy (preferably legal), and check it out! Our first self-titled album is also available if you're curious to hear what we sounded like 9 years earlier. * - in geological time