Sunday, May 10, 2015

How to set up a Fender Telecaster-style guitar

Today I’m going to show you how to set up a Fender Telecaster-style guitar. We are only going to do a basic setup, which is enough most of the time, but occasionally more is required, such as filing the nut, or doing some fretwork.

If you're setting up a Stratocaster-style guitar, you might prefer to have a look at this blog post: http://diystrat.blogspot.com/2011/03/how-to-set-up-electric-guitar.html
Alternatively, if you're setting up a Les-Paul-style guitar, you should have a look here: http://diystrat.blogspot.com/2012/09/how-to-set-up-gibson-les-paul-style.html
So what does a basic setup involve? Let me break it down for you, as follows:

  1. Checking and adjusting neck bow (how straight the neck is)
  2. Checking and adjusting saddle height
  3. Checking and adjusting the intonation (how far back or forward the saddles need to sit at the bridge to keep your guitar as in tune as possible no matter what fret you’re playing)

Those three steps will have a dramatic effect on your guitar and none of them are very difficult, or require particularly specialized or expensive tools. Here's today's patient:


1. Check and adjust neck bow (how straight the neck is)

Since we only want to check how straight the neck is, we need to isolate this aspect of the guitar. In other words we don’t want the height of the nut or the placement of the saddles to confuse us, so we take them out of the equation. Don’t worry; we’re not going to remove any of these components, just circumvent them.

I use a ruler to do this, but you can do it using only strings. I’ll describe both methods below.

Method A: Using a ruler

Get a ruler (or straightedge if you want to be all fancy) that is at least as long as the neck, but not so long that it reaches all the way from the nut to the saddles. If you can’t get one between these lengths, and are willing to sacrifice a ruler, get one that’s too long and cut it to length. Alternatively, you can just cut a little out of one edge so that you can still make full use of the other edge of the ruler.

Now lay the edge of the ruler along the frets (don’t rest it on top of the nut or the saddles).


Method B: Using the strings

First, put a capo on the first fret. This stops the nut from having any influence, say from being too high/low.


Next, hold down the low (thick) E string on the bridge side of the highest fret. This stops the saddles from having any influence.


No matter whether you used method A or B, you can now go about measuring the neck bow. This is done by measuring the string height (the gap between the ruler/string and the top of the fret) at about the 8th fret. There is a lot of debate over how straight a neck should be, and in fact it really is personal choice, but a height roughly the same as the thickness of a B string is a good starting point. Personally, I use a 0.012” feeler gauge to do this, but you could use a B string. Simply slide the feeler gauge/B string into the gap to see if it is too big/small.


If the gap is perfect, congratulations – you may now move on to step 2.

If the gap is too large, then you need to tighten the truss rod a little (similarly, if the gap is too small, you need to loosen the truss rod). Locate the adjustable end of the truss rod. On this guitar it is at the head of the guitar and requires a 4 mm Allen key, though your guitar may be different.


On some Teles, it is located at the other end of the neck. This is a pain, because every time you want to make an adjustment to the truss rod, you will need to loosen the strings, remove (or partially remove) the neck, adjust the truss rod, re-attach the neck and tighten up the strings again to check the neck bow.

Anyway, here’s how you adjust the truss rod. This must be done with the strings tuned to whatever pitch you usually use. If your neck is too bowed (the gap you just measured is too big), you tighten the truss rod by turning the Allen key (Allen wrench), screwdriver, or socket (the tool required depends on your guitar) clockwise. It is recommended that you only turn the tool a quarter turn (or even an eighth turn) at a time and then give the neck some time to settle. You will also need to make sure the strings are still properly tuned after each adjustment.

CAUTION: If you find that the truss rod is very difficult to turn, then stop now and take your guitar to the guitar shop. It may be that there is a problem with the neck or the truss rod and you may damage the guitar by forcing it. Believe me, you do not want to damage the truss rod.

If, instead of tightening the truss rod, you need to loosen it, do so by turning it anti-clockwise (counter-clockwise). Again, a quarter turn at a time. Once you have got the gap to 0.012” (or whatever gap you prefer), you will have finished this step. Feel free to remove the capo at this stage if it is attached.


2. Check and adjust the saddle height

Firstly check and, if necessary, adjust the low (thick) E string height. Do this by adjusting the height of the saddle on the bridge (on this guitar, a 1.5 mm Allen key is required, though your guitar may require something else). Then this is done by screwing the outermost screw in or out. Since Telecaster’s generally have three saddles (each supporting two strings), rather than six individual ones, you will probably end up with them being at a bit of an angle, rather than parallel to the guitar. This is fine (if you happen to have six individual saddles, then for each one, I recommend that you try to keep the two screws at the same height as each other, although some people would disagree with me).


The question here is how high to make the saddle. Well, this is personal choice. Find somewhere were the string doesn’t buzz on any fret from being too low, but low enough that you can play up and down the neck easily. There’s usually a sweet spot where you can just start to detect some buzzing and you can leave it just a tiny bit higher than that.

Now do the exact same procedure for the high (thin) E string.

There are two ways that you can go about adjusting the other strings.

Method one: Adjust each string the same way as you just adjusted the two E strings.

Method two: Use a radius gauge, as follows:

Lay a radius gauge across your strings, close to, but not touching, the saddles. Adjust the remaining strings only (A, D, G & B) until every string is just touching the radius gauge. Radius gauges can be bought from numerous sources ( I got mine from http://www.stewmac.com), or you can make your own. Feel free to use Google at this point if you don’t know about radius gauges. Just make sure that you use a radius gauge that matches the neck of your guitar. Not all Teles have the same neck radius, so the best way is to rest a radius gauge on the neck of your guitar (with the strings removed if necessary) to find out which radius you should be using, as follows:


Incidentally, I use these snazzy radius gauges that can go either above or below the strings (below gives a slightly more accurate result, although the difference is arguable).



Please don’t take these measurements as the absolute final string height, but more as a good estimate. You can adjust them a little to your own personal tastes after this.

OK, that’s step 2 finished. Your guitar should be nice and playable now. However, it may not seem to stay in tune very well. That’s because the intonation might be off.


3. Check and adjust the intonation

The intonation here refers to the forward/backward position of the individual string saddles. By moving the saddles forwards or backwards, we are actually adjusting the length of the strings. Without going into too much detail, if the string is the wrong length, the positions of the frets will not be correct and the guitar will be out of tune on some of them. Adjusting the intonation is not difficult. All you need is a guitar tuner and a tool to move the saddles forwards or backwards.

Play an open low E string and make sure it is in tune (using the guitar tuner).


Now play the 12th fret of the low E string.
It should also be in tune. If it is too high, then you need to move the saddle back. This increases the length of the string. If the note is too low, then you need to move the saddle forwards. This decreases the length of the string.


Now check both the open and the 12th fret notes again. You’ll have to tune the open string again because by moving the saddle, the tension of the string will have changed and so will need to be retuned.

Once you have correctly moved the saddle so that both the open string and the 12th fret are in tune, you can move on to the A string. Ordinarily, you would repeat this step until all of the strings have been done. However, if you have three saddles rather than six, you may have to compromise a little and find the position where the pair of strings passing over each saddle are as well intonated as possible. One may end up being a mm too short and the other a mm too long. You will notice that I use “staggered” saddles on this particular Tele. They help minimize the compromise you will have to make, and if you’re lucky you’ll end up with something close to perfect.

That’s a basic setup done. Hopefully your guitar will now be easy to play and appear to be in tune no matter where you play the note.

Also, if you want to change the neck pickup height on your Tele, check out this post: http://diystrat.blogspot.com/2011/09/adjusting-neck-pickup-on-fender.html

Tuesday, April 21, 2015

Making a reverse/inverse RIAA attenuator



A couple of blog posts ago, we made an RIAA preamplifier (http://diystrat.blogspot.com/2015/03/making-riaaphono-preamp.html). Hopefully you understand what that is now, but if you don’t, maybe have a look at that post now.

As part of the process of making that preamp, I found it useful for testing purposes to have an inverse RIAA attenuator on-hand. Wait, a what? An inverse RIAA attenuator. It's basically the opposite of an RIAA pre-amp.

If we refer back to the RIAA Equalization Curve graph that we used on the RIAA preamp post, you'll see that it has two lines (see below). One is called the recording curve (dotted blue line) and one is the playback curve. The RIAA preamp follows the red curve. The Inverse RIAA attenuator follows the dotted blue one. If you were to put one after the other, you would end up with a flat horizontal line running right across the middle of the graph at 0dB.


So why would you want one of THOSE? Well in my case, it made it possible for me to take the line-out of any device, send the signal through the attenuator, and then feed its output into the RIAA preamp I was building at the time. If the output was back to line level, then I knew the preamp had no major problems (though I would still test it later with a record player for sound quality, etc.)

Now I understand that most people would not be in this situation, and therefore this attenuator would seem to be of little use. However, it does have one other fantastic use, and I wish I’d had one when I encountered this exact problem a few years ago. Imagine the situation—you have an amplifier with just a few inputs. One of those inputs is labelled “phono”, but you don’t have a record player, so it’s basically wasted. Well, with a reverse RIAA attenuator, you can plug just about any device with a line-out connection into the phono input using this attenuator as a go-between. In fact you’d probably get away with the headphone output of many devices, though you may have to play with the device’s volume levels to get a decent sound quality/frequency response—in fact I tested this with an iPod and it worked just fine.

Now, as I'm sure you know, an attenuator is the opposite of an amplifier. Since we’re not actually amplifying anything, we can do this circuit completely passively (no power supply required). In fact, it’s an incredibly simple circuit once you’ve worked out which resistor/capacitor values you need. This is no mean feat, but luckily there’s almost always someone else on the Internet that has already worked this kind of thing out. In my case I used this circuit, which I got from here: http://sound.westhost.com/project80.htm

I highly recommend visiting that site if you want a little more information about the circuit and how it does what it does.

The schematic is extremely simple, requiring only four (or even three--see below) capacitors and three resistors for each channel. So simple in fact, that you don’t require a circuit board.

These are the values I ended up using:

R1 = 909k
R2 = 75k
C1 = 3.3nF
C2 = 270pF
C3 = 1nF
No need for C4

I boxed them in a fairly small project box with a couple of RCA jacks at each end.


Then covered it up and marked which end was which (don’t mix this up).


And here’s an action shot of me using it to test out the RIAA preamp I made in the previous post:


This ended up being a simple, cheap and fun project and I ended up with a very handy little device.

Wednesday, April 15, 2015

Building a Bazz Fuss fuzz pedal


Hey, what should we do today? How about making a fuzz pedal?

Cool, I knew you were up for it.

As you may be aware, I’ve recently been helping my friend Adam with a few guitar projects and he was keen to get started on pedal making (specifically a fuzz pedal). I suggested the Bazz Fuss as an easy starter project. It’s only 5 components (and a pot) and it sounds good too. It's designed primarily for a bass guitar, but it sounds great with a normal guitar too.

Here it is (note that I laid mine out slightly differently, and I eventually swapped the 10k resistor for a 100k one):


And here's my very professional layout:



Since I hadn’t already made a Bazz Fuss myself, I decided it might be fun to do so. Apart from having one for myself, it would be handy to have one to refer to if Adam ran into any issues while he made his.

I decided to challenge myself a bit and see if I could fit it into a Hammond 1590A enclosure. They’re pretty hard to find round these parts, but I did manage to find an enclosure that had almost the same dimensions. In fact it’s slightly tighter than a 1590A, but hey, that’s just part of the fun, amirite?

Just for reference, a Hammond 1590A enclosure measures 93 mm x 39 mm x 27 mm. Mine measures 90 mm x 36 mm x 30 mm. The walls are a bit thicker and there are some extra bits inside which will make it even more cramped.

Here’s the enclosure in question: 


And here’s the inside. You can see some additional metal in there that you would ordinarily screw a ground screw into, as well as some circuit board slots (which I won’t be using).


Here’s a bit of a test fitting just to see if I can even get the main mechanical parts in there:


The answer is “just about”. So we start drilling very carefully.

First the switch:


Then the first jack:


 
Second jack in place:


I’m testing the jacks with something plugged in, just to make sure I can still do that without any contacts banging up against anything they shouldn’t. In a normal-sized enclosure this would be less of an issue, but things are very close together in here.


Next to go in is the DC-in jack, since there’s really not much flexibility there. Once that’s done we’ll be able to see what space is left for the pot and the circuit.


OK, the pot can just about fit in here, with the legs bent up (in fact I ended up cutting off parts of the legs to help them fit).


Just one more item and that’s the LED. I decided to go with a smaller 3 mm LED. And I also decided to make use of one of the little grounding threaded holes I mentioned earlier. 

This (little) one, which I drill all the way through so the LED can sit in it:


Here’s how that looks from the front:


And we’re done (apart from the circuit and wiring of course):


Here’s how THAT looks from the outside:


When you’re trying to fit a circuit into something this small you really have to think about how big your circuit board can be and still physically fit. Not only that, but things like whether the capacitors can sit vertically without hitting the back of the enclosure (they couldn’t, which is why they’re lying flat).
Anyway here’s the board done, and wired to the pot:




I stick some insulating material between the pot and the board so there are no short-circuits:


Before we wire this up, I’m going to paint the enclosure. How about blue?


And here it is wired up. Not the easiest pedal wiring job I’ve ever done.


I’ve put some insulating tape anywhere where there was a danger that something might touch something it shouldn’t, and that included the inside of the back cover.

 
Finally it’s time to put it together.


As you can see above, my "Sharpie" decal didn't turn out as well as I'd hoped, so I made something up in Illustrator, printed it out on normal paper, stuck some Scotch tape on top to make it look laminated, and then put double-sided sticky tape on the bottom. Et voilĂ , a cheapskate decal.


The first time I tried it out, it sounded bad. It worked, but not well. I replaced the 10k resistor with a 100k one and it sounds great now. You may want to do the same.


Here's a quick and dirty (see what I did there?) demo of the pedal:



Friday, March 13, 2015

Making an RIAA/phono preamp




Before we start today's blog post, I think I really need to clarify what we’re discussing. I’ve recently got back into vinyl in a big way. Part of the reason for this is the fantastic “Vinyl Decision” in Taipei, run by a couple of very fine gentlemen by the names of Mark and Terry (https://www.facebook.com/VinylDecision / http://www.vinyldecision.com/). If you're in Taipei, and like music, pay them a visit. A recent purchase from there brought back memories of trying again, and again (and again) to play guitar like my guitar heroes as a teenager in the 1980s.

In fact, vinyl is making quite a comeback worldwide. A lot of people are realizing that digital versions just lack some of the personality that vinyl can provide. Many of them are buying old record players/turntables and wiring them up to their modern amps. However, they are often disappointed to find that the output audio is very quiet and lacking bass. This is because records are/were recorded using a very specific frequency response. The output of a record player is much lower than “line level”, but it is also much heavier on the treble and lighter on the bass. This frequency curve is what is known as the RIAA (Recording Industry Association of America) equalization curve. This was necessary primarily because heavy bass would have the needle jumping around too much on the record, affecting sound quality, and, I’d imagine, increasing wear and tear. Additionally it allowed the grooves to be thinner, hence allowing more grooves (and therefore longer playing time) per record.

The RIAA Equalisation Curve:


Older amps had a specific input labelled “phono”, which specifically catered to record players. This input would be wired to a built-in preamp which would not only amplify the signal to line level, but would also correct the frequency curve, hence enabling the amp to output the sound as it was originally intended. Many newer amplifiers do not have a phono input and therefore an external preamp is required between the record player and the amp to enable the use of one of the line-level inputs.

And that’s where today’s project comes in. We’re going to make an RIAA/phono preamp.

There are many, many preamp schematics out there—some simple, and some insanely complex. I wanted to find one which was relatively simple, while still accurately correcting the RIAA recording frequency curve. I finally settled on this one: http://phonoclone.com/diy-pho5.html (“The Very Simple Phono Stage”). I highly recommend you go to that page and read through it if you decide to tackle this project. It’s very well explained and highly educational.


Rather than build a power supply, I decided to buy a 30V DC one ready-made, and then split it so that it would have +15V, OV and -15V. To do that, I made a simple voltage splitter like so:


And a filter where the power plugs in to remove any unwanted hum from the power supply, like so:


Additionally, I added a diode right where the 30V meets the board to protect the circuit in case anyone ever plugs the power supply in the wrong way around.

I also decided to add some small 100nF capacitors at the +15V and -15V legs of the chips to reduce any picked up noise to a minimum.

OK, let's get going. We're going to need an enclosure. Here’s the box I’m going to use with my markings for where to put the connectors:


From left to right, it’s going to have a grounding connector (which may or may not be needed depending on whether there is a humming noise – note that the humming noise can sometimes be removed by unplugging your record player, turning the plug around and then plugging it back in [assuming it’s symmetrical]), left output RCA jack, right output RCA jack, left input RCA jack, right input RCA jack, and finally the power input (30V DC negative sleeve [it is imperative that the 0V from the power supply is electrically isolated from the enclosure, so don’t be using any metal connectors that might join them]).

Here it is with the holes drilled and the connectors, erm, connected:


It’s a good idea to test stuff like this out on breadboard before you switch your soldering iron on. Here’s an early version of mine:


Once the circuit design is more or less finalized, it’s time to lay it out for veroboard, like so. Yes, this is how I do it:

And just for you, here it is done properly on the computer. You may notice a few small changes between the initial pencil sketch and the final layout. As with all images, you can click to enlarge.
Here we have the components mounted on the board:


Now it’s time to think about mounting the board in the box. It’s pretty important to secure the board in such a way that it doesn’t move around and touch something it shouldn’t. You can see here that I’ve drilled a couple of holes through the board:


Now we drill a couple of holes in the enclosure that match up with the hole positions on the board. I’ll eventually use plastic mounts to hold the board securely in place.



Before placing the board in the box, we add the wires (apologies for the overexposed photo):

Now that the board’s in place, we can connect the wires to the connectors, like so:


Once we're happy that the circuit’s done, we secure the connectors in place with thread lock:

Here's how it looks after that:


Finally, a little bit of the old in and out so we don’t mix up the cables:


And we're done. I'm happy to be able to verify that “The Very Simple Phono Stage” sounds fantastic.