curtisa

So sustain on open strings is a function of rigidity and hardness of the nut material. Which is why a softer material (graphite) or a mechanically sloppy material (roller nut) will sustain less than solid brass, If you could mill a nut from stainless steel I'd expect it to perform as good as, if not better than brass. The roller nut may also be hamstrung in that there is also less material to transfer the strings vibrations into the surrounding structure of the neck and body. So despite being made from similar materials as the solid brass nut, each roller has to spin freely on a tiny pin, the string being in contact with only a tiny portion of that roller as it passes over, and the roller itself having contact with only a tiny portion of the pin. Whereas the solid nuts have all their mass directly seated into the neck and the string (ideally) in contact with the full length of the slot as it travels from tuner to neck. Have you tried bone yet as well? My gut feel is that it'd be similar to graphite in terms of overall sustain. Thus, at the other end of the guitar, I'd expect to see a similar correlation in sustain when comparing between roller saddles, brass, steel, or graphite, inlcuding the way the saddles are mechanically coupled to the body - fully floating trem, trem blocked off, hardtail, tune-o-matic etc. Mind you, I'd also expect the differences between nuts to vanish as soon as you fret a note. Comparing differences in sustain between nut materials is fine, but at the end of the day that's only six notes out of a possible 144, and not many players will find an application for just plucking the open strings at 40 second intervals...except for perhaps bands like Sun O))) Perhaps you can investigate using fretted notes as control tests to verify that the age of the string isn't gradually skewing your results as you go?

So was it a resonance stall or physical interference?

Aye, I can see that contours may be adding a bit too much to the mix. Just the way my brain was heading when I saw the pic first thing this morning prior to my first coffee for the day

The first one probably doesn't need much analysis based on what is already detailed in the datasheet. All the information is already there. In broad terms, the LM386 is a single chip, low-wattage power amplifier intended for battery operation where sound quality isn't critical. Maximum output is about 1W. Circuit gain is adjustable between 20x and 200x by varying the impedance between pins 1 and 8. As you have it shown, your LM386 is configured for a gain of 20x, plus has a volume control at the input. The second one is interesting, but it will never perform well. Essentially it's just an opamp with a current-boosting output stage made up of push-pull darlington transistor pairs T1/T2 and T3/T4, to allow the opamp to drive a speaker. The method used to provide the current boost is really odd though. Rather than simply taking the output of the opamp and boosting it directly, they're measuring the current being drawn from the supply rails via R4 and R5 while the opamp is running and using that the boost the output. Circuit gain is fixed by the ratio of R3 to R1 (270k/10k = 27x). High frequency response has been limited by placing C1 in parallel with R3 to about 11.8kHz (1/(2 x 3.14 x 50pf x 270k) = 11789Hz). I get the impression that the second circuit has been cooked up as an academic exercise rather than for sensible design. The IC specified (LM741) is a truly awful unit by today's standards. Even the choice of transistors seems haphazard, as none of the types specified come from the same complementary familiies - BC178 is a small signal silicon NPN, AC108 is a small signal germanium PNP. 2N6107 (PNP) already has a complementary unit available in the same series (2N6292 NPN), so why they've specified a random 2N5294 seems weird. The method employed to develop sufficient current through R4/R5 to drive the push-pull stage is to load the output of the opamp with an extremely low 47ohm resistor (R6). Maximum output voltage swing on the LM741 is to within about 3V of the supply rails, so even assuming you can drive the LM741 hard enough to achieve +/-9V on the indicated +/-12V supply, the LM741 is going to hit the brick wall long before then because of the built-in current limitation of the chip. Current output on the LM741 is limited to +/- 25mA, so max clean voltage swing you can expect is a measly +/-1.175V. It will never deliver the 12W output that's promised on that page, and will spend a lot of its time distorting like crazy. There are better ways of making something that will move a speaker.

[Slow-motion dives across the room while Samuel Barber's 'Adagio for Strings' plays in the background] Nooooooooo, Annnnnnndeeeeeeee!!! Oh, I dunno. Have a nice cup of tea? Play a round of Scrabble? Read the Sunday Times? Watch the latest episode of Midsomer Murders? Seriously though, the refinements you're proposing still look like they fit perfectly with the overall package. All I can say is that you're braver than me for going to those lengths having only just completed the guitar. To be honest, based on the MSPaint-ified blackening you'd applied to the pic, I initially thought you were wanting to add bevelled contours to the lower bout and treble cutaway.

What you want to use is an on-off-on mini toggle to short out (bypass) the unwanted coil. When in the centre position neither coil is shorted out and the whole humbucker as operated with both coils in series as normal. Moving the switch to either extreme places a short around one coil, allowing the remaining coil to be connected to the output. The section labelled 'SPDT Center OFF Switch' on this page shows how it's done.

...And if you ever need a bit of rest after rocking out a bit too hard, you can just flip it over and use it as a chair to park your arse upon. Stellar job once again, Andy. I must stop by ( ) one day and have a go on some of these creations of yours. So what do all the switchy-knobby bits do? There a few more there than what I've seen you use recently.

Thank you, and yes, that is the very guitar that I used it on. The other thing that may require a bit of thought is if the single screw that attaches each tuner to the baseplate is enough to hold each tuner to your headstock without accidentally swivelling the tuner while you operate the knob. Normally each tuner is prevented from skewing around by all six being held captive inside the bridge baseplate. With yours splayed out as you have them, there's not much to stop them swivelling around the single mounting screw that each one has.

I've used that bridge on a build in the past. The tuners won't win any awards for quality but they are perfectly servicable. I'm not entirely sure if you can mount them exactly as you have shown them though. I had a vague idea at the time that each brass tuner platter requires the next one to be seated along side it to fully support the axle in a conga line fashion. Keep the wrench handy - the lower strings are difficult to tune by hand without it.

I don't know the specifics of you bass, but I'm guessing that the controls are likely to be one switch for each pickup (on/off), master volume and master tone. If so, then the Gibson SB350 wiring would be a close match to try and replicate the missing parts. Switches look similar to Fender Jazzmaster slide toggle switches. You'll need to measure the screw spacing, lever travel and lever dimensions to confirm if you can get a drop-in replacement. Although there may be nothing wrong with the existing switches, so don't create more work for yourself if it's not necessary. Test them first once you get the volume pot and input jack installed. Control knob might be difficult to obtain. Looks like the volume pot was stamped with a 'V'. You may have to replace both knobs for consistency if looks are important, with say a Fender Strat 'volume' and 'tone' knob set. Also looks like your bass may have come with a scratchplate and thumb rest mounted on a metal bracket, Les Paul-syle. There might be a screw hole in the side of the body where it may have been fitted, and also another one on the treble side just near the fretboard. You're unlikely to find an exact replacement though, and you may have to make a new one from scratch if you're going to restore it to that degree. You might be able to get a pre-slotted nut that will fit your bass. The critical dimensions are the string-to-string spacing or the E-G (overall) spacing. You can always take an overly wide or overly tall nut and reduce it down to fit your instrument provided the strings rest properly within the boundaries of the neck. A good starting point would be to measure the width of the neck at where the nut needs to sit and subtract 3mm from each edge. This would be the point at which the outer edges of the E and G strings would sit on the neck, giving sufficient leeway for the outer strings to be depressed without rolling off the edges of the frets.

Flat spot on the high E saddle (makes a sitar-like buzz)? Something rattling elsewhere on the guitar in sympathy with the string (tuners, strap buttons, trem arm etc)? Truss rod rattle (tap back of neck and see if you can hear it rattle)?

Never doubted it for a second.

Fascinating. Kinda like watching an Airfix kit go together

Commas save lives. 'Let's eat, grandpa' 'Let's eat grandpa'

Do tell.

Aye, I have the RT700 (actually marketed here as the RT700CX, whatever difference that makes), and find it a really good alternative to the bigger units when I don't need the extra horsepower or mass. Haven't had an issue with the collet. My unit shipped with two spanners - one for the collet nut and a smaller one to grip a pair of flats on the spindle shaft. I don't bother with the pushbutton shaft lock when installing bits. All I usually do is insert the bit into the collet, tighten the collet nut finger-tight and use both spanners in a squeezing motion one-handed to get the collet snugged up onto the shank. Undoing can be done in the same motion by ofsetting the two spanners in the opposite order and squeezing together again.

Clamps. And lots of them. No other way of doing it as a hobbyist IMHO. You can spread the load a little by using cauls between the clamps and the body (ie, something large and flat to distribute the pressure being exerted by the clamps), but it won't reduce the clamping quota by a great deal. Spool clamps I've never tried, but I suspect they will only help you at the extreme edges of the gluing surface. I'd imagine they only provide useful pressure within a centimetre or two from the edge of the body. Could be handy on the skinny parts of a body, such as a cutaway or the horns on a Strat-style shape, but you'll still need something with more squeeze for the bigger areas.

Damn, she moves quick. Hope your stand is nice and rigid. The inertia in those rapids will shake the machine off the table! I'm not getting anywhere near those speeds (I'm limited by the capabilities of my parallel port, can't remember exact rates but I think I max out at 100ipm), but my machine is probably less than half your size so I'm happy with what I can get away with. What's the little ethernet board you have in the lower-right of your control box?

Finding a perfect replacement may be a bit hit and miss, but perhaps look for: Number of frets matching original neck Scale length matching original neck Dimensions of heel area - length and width of flat portion of heel. Height of neck from face of heel to peak of fretboard Radius of fretboard Some of these dimensions may be hard to come by (other than radius and scale length) and I suspect that most manufacturers may not give them out, other than to say 'fits Strats'. You can always take a punt and order a 'Strat-ish' neck and hope for the best, but if it doesn't fit well enough you will have to employ some woodworking skills to make it fit. The fit issues that you may come up against aren't insurmountable (heel wrong size and/or shape, thickness of neck at heel too tall/short), but they are beyond the scope of a simple 'drop and swap' of guitar parts. Warmoth may be able to supply dimensions if you send them an email?

Moved to the Solid Body Guitar and Bass Chat Section for better housekeeping.

I'd evaluate the guitar as a whole before deciding the neck needs work. You haven't mentioned whether it plays OK or not (disregarding for the moment what things look like). I have an old Pacifica 112 with a few visibly flat frets in the first five that still plays perfectly OK. My suggestion is to first check that it is set up correctly before assessing the neck and frets for faults: Tune guitar to pitch. Use fresh strings. Check and adjust neck relief via truss rod under string tension. Check and adjust action at saddles. Check and adjust intonation at saddles. Re-tune as appropriate as you go Play the instrument and check to see what works and what doesn't. Do certain frets buzz? Do open strings buzz? Is intonation bad in the first few frets? There are plenty of tutorials out there explaining how to adjust neck relief, action and intonation. Google is your friend. If you decide after doing the above there is work to be done, then you can start examining things in more detail. This may amount to nothing if all that needs to happen is the guitar requires a setup (as per above) I assume by the frets needing 'rounding' you mean 'crowning' (ie re-shaping the peaks of each fret into a smooth peaked shape). Again, I'd only avocate doing this if there is actually a problem being experienced, either with low spots in frets causing buzzing on adjacent frets, or introducing problems with the feel of the string over the fret. Don't get too hung up on the fret rocker indicating a problem with a couple of frets - listen to the guitar first to decide if there is something that needs work. The fret rocker should only be used to identify where an issue lies, not necessarily that there is an issue. I'm not sure what you mean by 'rake'. Perhaps the amount of backwards tilt each slot in the nut has? A very flat (horizontal) nut slot may introduce a sitar-like buzz on the open strings. A slight backwards angle of each slot should guarantee the string leaves the nut slot at the peak of the slot. If it does turn out to be the case that the slots are too flat (or even angled forward), at best it will require a set of gauged nut slotting files to change the angle, and at worst a new nut (plus the files too). I usually check nut slot height by depressing the string between the 2nd and 3rd frets and checking the gap between the string and the 1st fret with a feeler gauge. I aim for a gap of around 0.007" to 0.010"

I should be OK. The drivers I'm using are generic M542's (similar looking, similar pinout, different specs), and the DIP switches appear to be doing the right thing.

Nice one, Mike. You and I seem to have used a lot of similar electrickery components. I see a lot of familiar-looking parts in your control box. I'm within a hair-breadth of completing mine too. Just need to fit up the Z-axis limit switches and I'll be ready to destroy some endmills.

Fill and drill would be the preferred way to do it. But if that's a bit difficult to pull off, maybe wrap a tiny bit of electrical tape around the shank of the ferrule to make it a snug fit in the oversized hole? String tension should retain the ferrule in place under normal circumstances; you only need enough friction to stop the ferrule falling out and being misplaced when you change strings.