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My store is not taking any orders today due to health reasons which limit to my productivity.
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My custom harmonicas, combs and tools are made to order. If items are out of stock on my website, it's likely due to my workload is at the limit. Please see my dealers for all items I offer.
Maximum production times may be up to 16 business days for combs and tools. Current production time for custom harmonicas are shown on the top of the custom page.

Thanks for your support.
Andrew

Andrew's blog

Custom Harmonica Comb - Andrew's method

I learned how to make combs from friends with over 100 cumulative years of machinist experience! This is my low-tech, high-precision method of making exquisite harmonica combs. You can use this method to flatten the stock comb on your harmonica to make it play better.

The diatonic harmonica is made of solid pieces that must fit together in a way that is airtight. Mass-produced harmonicas often are not airtight and can be improved with a few minutes work.

This process is usually a little faster but the using a camera slows things down a bit.

Use this process on Hohner Bamboo Laminate (Crossover and Thunderbird) combs or the stock Suzuki Manji comb. You can also flatten a comb made of Corian or any other solid-surface material using this method. Be careful not to drop Corian combs - they shatter.

Wooden combs will swell. To flatten wooden combs like the Seydel 1847 or Marine Band Deluxe/1896 combs, I recommend you seal the surface after you flatten. Check for flatness after you seal, too.

Do not use this method on recessed-type harmonicas like the Special 20, Session or HarpMaster harmonicas. Those harmonicas use a different design concept. Checking and adjusting flatness on those combs requires a different strategy. Straightening and flattening the reed plates will make the best of the thin plastic combs in those models and will offer you great results. For perfectly flat reed plates, use The F Tool™.

This is the comb tool™. I meticulously flatten the top edge. *Only* the top edge is flat - we will be using that edge as a reference.

My comb tool is a working copy of a high-precision straight-edge (some call this a machinist square) precise to .000025" per 6" (25 millionths of an inch). The original stays in a drawer! If I were to use it on every comb I make, it would eventually wear out.

You can get a set of my comb tools here: Comb Tool™.

We will be measuring flatness along the left-to-right axis.

We will be measuring flatness along the up-and-down axis. That means in between every tine.

We will be sanding the comb surface. Tape a piece of 220 grit sandpaper to a flat surface. I use a granite surface plate but any flat surface will do. Don't obsess about the flatness of your working surface. The only thing you need to make your comb perfectly flat is a flat reference.

Place the comb tool over the comb to distribute the weight of your fingers evenly over the surface of the comb.

Move the comb around in circles in both directions until it feels smooth. This usually takes a few seconds. Flip it over and do the other side.

Place the reference along the surface of the comb and hold it up to the light. Hold it only on one side so that you can see how the other side behaves.

Switch sides. this gives us a good clue as to where the comb is bowed and where to flatten.

Put the comb down on the flat sandpaper and apply finger pressure where you want to flatten. Drag the comb along the sandpaper. Check flatness and repeat until it's flat.

Rotate the comb so that you are checking the tips. One tine is leaky here. Flatten the other tines to fix this.

Check in between each tine.

Switch your grip from side to side to reveal where the curve is.

Apply finger pressure and drag the comb to fix.

This is flat.

You can use the tool to apply even pressure to a portion of the comb - just like you used your finger. If the comb was unflat in this area, I would apply pressure like this:

Use this technique on both sides to fix a curve that is concave downward.

In summary, the hard part is measuring flatness. Once you can tell where the comb is not flat, it's easy to fix.

Extra tips!

Here are some extra tips on using my comb tool:

Comb tool extra tips page

Perfect Pitch: Using breath dynamics for tuning

This is part of a series about tuning the diatonic harmonica

Part 1 - Tune a harmonica using your ears and a simple chromatic tuner
Part 2 - More Better - ultra precision tuning
Part 3 - Perfect Pitch: Using breath dynamics for tuning
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The diatonic harmonica can be tuned to different temperaments.

Equal temperament is when each note is tuned to its exact pitch. When the notes of a chord are played together at ET, the chords can sound dissonant because the harmonics aren't in sync. Just intonation means some of the pitches are tuned a little sharp or a little flat so that when played together, the chords sound very smooth. The harmonics are in sync.

Here is a diagram of the waveforms of the tonic and third superimposed:

On the top, you can see that at ET, only one cycle is in sync. On the bottom at JI, every fourth cycle is in sync. That note needs to be 13 cents flat to sync up.

Here is a diagram of the the waveforms of the tonic and the fifth superimposed:

On the top line, at ET, only one cycle is perfectly in sync and we can see it rapidly go out of sync as you move away from the center. On the bottom line, every third cycle is in perfect sync. The interval of the fifth is a powerful sound (guitar players call it a power chord!) because the waveforms are in such harmony. But it only took 1.5 cents to disrupt the timing and make it sound less powerful.

There is no way you can tune a diatonic harmonica to within 1.5 cents accuracy by looking at the needle on a chromatic tuner.

Why?

Harmonica reeds don't always vibrate at the right pitch. If you apply too much air flow, the reed will vibrate too slowly and the pitch will go down. The note will sound flat. That's because you are making the reed move a lot further that it is designed to do (greater amplitude) and it has to travel a greater distance with every vibration.

Likewise, if you play the reed with much lower breath than intended, it will hardly move. Since it will only travel a short distance, it will make the trip is less time and the frequency will go up - the note will sound sharp.

Fortunately, there is a very large "sweet spot" where the reed responds to a range of air flow and can stay reasonably on pitch - within a few cents - even if you don't always use the same breath force to play that note. That's why we can play the diatonic harmonica with such a large range of dynamics.

The fact that the pitch varies by a few cents with breath force is both a curse and a blessing when it comes to tuning.

It's a curse because you can't just tune each hole to a specific note. You need to offset the tuning of each reed so that you meet the following criteria (to name a few):

- the single notes are on pitch
- octaves are on pitch
- the other intervals (fifths, thirds) are on pitch
- the three blow and two draw are enharmonic equivalent (the same note) but they are not the same note (blow three is a fifth, draw two is the tonic; each one has a different offset.)

To meet all these criteria you need high precision. That's where using dynamics actually comes in handy.

Longer reeds flatten more than shorter reeds as you increase air flow. When you play two reeds at the same time you can count on the lower reed to flatten more that the top reed as you increase air flow (because it's longer).

So if two reeds are very close to being in tune, say, they both register the same on the chromatic tuner but you hear beats when you play them together, you can tell which one is tuned higher by playing with increased breath force and listening to what happens.

- If the beating slows down or disappears when you increase air flow, the bottom note is a little sharp.
- If the beating gets worse with increased flow, the top note is a little sharp.

Here's another way of looking at it. This is an animated GIF of two waveforms superimposed. The waveforms are an octave apart. Both waveforms lengthen (drop in pitch) as breath force increases. The lower note in the octave is sharp but with increased breath force it goes into tune with the higher note for a short moment.

In this case, we should either tune the lower note a little sharper or flatten the higher note.

The effect of flow rate on pitch

Here's an example of using breath dynamics to tune with precision:

How to bend notes on the diatonic harmonica: What is “Bending Energy”?

Warning: This blog post contains physics.

Here is an excellent demonstration of what happens when we bend notes. See what happens at the 3:00 minute mark.

When he finds the volume of the tube that is resonant to the frequency of the tuning fork, the sound increases. The frequency of the tuning fork stays constant though. Harmonica reeds are special because they can vibrate at different frequencies. We can make them vibrate faster or slower.

We apply “bending energy” by changing the size of the oral cavity just like professor Sumner Miller changed the size of the resonance chamber (cardboard tubes). Resonance is what applies kinetic energy to the reeds to make them vibrate at the desired frequency. If you want the reeds to vibrate slower, you open up your oral cavity to lower the resonance frequency. The reeds follow. It’s as simple as that.

Hopefully an understanding of what happens as you play a bent note can help you learn how to execute the technique.

Knowing the physics behind it allows you to free yourself from overthinking things. Don’t worry too much about tongue position, “U”-shape, “W”-shape, “G”-spot.... Just make an air pocket in your mouth and when you find the right size, the note will bend. Figure out what works for you to be able to re-create an air pocket of exactly the correct size every time you want to play that note.

It’s a little bit of a moving target when you consider that as you inhale, the tissues of your oral cavity will suck in and the air pocket will shrink. Conversely, the air pocket will grow when you blow bend because of the positive pressure. But with a little practice, your mouth will figure out how to keep the size of the air pocket constant despite these opposing forces.

Your ears play a big role in this. But the interaction between your voice, your ears and the shape of your oral cavity is automatic (or “autonomic”) so no instructions are required - other than to mention to make sure you can hear yourself play!

Overbends are just like regular bends!

Overbends are a little more complicated because we need both reeds (blow and draw) in the system to respond to the same resonance in different ways. One reed needs to stop moving while the other one needs to vibrate at the correct pitch. The trick is to get the reed that is standing still to stay still even though we are applying airflow to the system.

Sometimes out-of-the-box harps are set up to allow this to happen. Sometimes, they are set up to inhibit this. It’s the luck of the draw. It’s a common misconception than you need to practice overbends for years before you can become good enough to play them. The truth is that overbends require breath control, resonance control and a harp that is set up to cooperate.

It’s likely that you can learn to use overbends musically in a matter of weeks with the proper harp and some dedicated practice. You don’t need to build muscle over several years like a bodybuilder. You simply need to learn fine motor control.

I really enjoy watching professor Sumner Miller. Here is another video from the good professor where he describes the phenomenon of beating. Again, watch starting at the 3:00 minute mark:

Hearing the beating is a very important part of how to tune a harmonica.

More Better - ultra precision tuning

This is part of a series about tuning the diatonic harmonica

Part 1 - Tune a harmonica using your ears and a simple chromatic tuner
Part 2 - More Better - ultra precision tuning
Part 3 - Perfect Pitch: Using breath dynamics for tuning
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Can you have too much of a good thing? Probably.

Can a harp be in absolute perfect tune? Maybe. If you don't care all that much about harmonica tuning (as long as your harp doesn't sound too bad), you can stop reading this and go back to playing some mean harp or practicing scales.

You can find a straightforward method of tuning a diatonic harmonica here: Tune a harmonica using your ears and a simple chromatic tuner. That will get your harp sounding very nicely.

If you obsess about tuning and are willing to spend a considerable amount of time and effort to get it perfect, read on!

In summary, we will apply the same strategy we've used to get the octaves in tune to the fifths and thirds.

Here's an important fact: You need to tune every Fifth with as much accuracy as you can.

What's so special about the fifths?

Every note of the scale has a purpose. For example, the Thirds and the Sevenths give the scale it's general sense of being (major, minor, dominant...). Fifths imply the Tonic; they are closely related to the tonic. It's important to get the tuning of the fifth (and fourth - same thing) right to make the chord sound nice.

Since the tonic and fifth are so closely related, the margin of error is considerably tight. A very small adjustment can go a long way. Often a fifths is tuned to less than 2 cents from ET, so even if you like your harps tuned to ET, you should be able to get away with such a small offset - you get the best of both worlds.

No chromatic tuner will be of help - you need to use your ears for adjustments this precise.

There are a lot of fifths on the standard diatonic harp. Every arrow in this picture is an interval of a fifth. If you enjoy tuning, dig in!

I can't tongue-block these intervals without affecting my embouchure which will cause some bending of these notes. That's not helpful to precise tuning! To play these intervals with a natural embouchure, you can isolate these pairs of reeds with the cover plates off using one finger to mute the thirds.

There are two chords on the draw plate so there are two different Fifths! The 2 draw is the tonic of the 1-2-3-4-5 draw chord. But the 4 draw is the tonic to the 4-5-6 minor chord. So 2-4 draw is an interval of a fifth, but so is 4-6 draw. These notes are repeated up the harp so 6-8 is a fifth, too.

Waitaminute! 6-8 is a fourth! Yes, but 8-6 is a fifth!. Take a minute to think about that...

...

And 8-10 is a fifth.

So tune the fifths with your tuner and then fine tune them with your ears. Play the tonic and the fifth and eliminate beating in the same way you eliminate beating when you tune octaves (using variable breath force to figure out which way to adjust the notes. See here: Tune a harmonica using your ears and a simple chromatic tuner. These beats are a little harder to hear than straight octaves, but they are there.

Thirds anyone?

Now that you have tuned all the fifths to perfection, can you use the same process with the thirds? Sure. Play the tonic and third together and fine-tune it to eliminate beats.

On the draw plate, there are two chords so there are two thirds. The 3 and 7 draw are major thirds to the 2 draw. The 5 and 9 draw are minor thirds to the 4 and 8 draw. Since major thirds need to be tuned about 12 cents flat to be just, you can compromise and find a nice sounding spot in between equal (0) and just (-12). Minor thirds are just at +16 but they sound pretty good near zero.

Remember the 5 draw is also the flat seventh of the 2 draw as well as the minor third of the 4 draw. What sounds good for one may not sound so good for the other. You decide what's best...

This is an extended French TunerTuner™. They are not part of my tool kit but are available separately.

What does it do? It helps tune the Fifths, Thirds as well as the Octaves on the blow plate.
The extended French Tuner works just like the regular FT. It plays octaves on one side and plays the other intervals on the other side.

Octaves:

Fifths:

You don't need any fancy equipment to tune properly. Even the French tuner/extended FT is just a tool to speed up the process. Use your ears. I'm posting these images to offer you a further visual example of what reeds to tune as pairs.

Some points to remember about tuning intervals relative to the tonic:

- If you play both the Tonic and the Fifth, a chromatic tuner will indicate the tonic - even if the tonic is the higher note (example, 3-4 blow or 6-8 draw.)
- Use your ears just like when tuning perfect octaves.
- If you hear beating that disappears when you increase your breath force, the bottom reed is tuned higher than the top reed (again, even if the bottom reed is the fifth)

Happy tuning!

Harmonica Repair Basics

Rockin Ron told me that he gets quite a few technical support questions about replacement reed plates. The harmonica looks like a simple instrument but once you have taken it apart for the first time, you realize how important all the little details can be!

Here's a video about the basics of installing new reed plates into your favorite harp:

The F tool™

The F Tool™ is now available in the Tools section

A well-playing harp has a solid connection to the vocal tract. A big part of what makes it is easy to play, sound nice and fat is that it's airtight.

If it leaks air, the connection between your vocal tract and the instrument is weakened and the harp feels stiff. The tone is also weaker.

The good news is air leaks are fixable! In fact, that's the fundamental step in improving a harmonica. If you skip this step, you will usually end up working against yourself further down the line.

The detailed instuctions on How to use the F Tool are here.

Producing CNC milled combs revealed!

I design my combs myself and produce them using my CNC mill. Here's a breakdown of the process.

The combs are cut. Water is sprayed on the surface as the mill works to cool the bit as it cuts. Keeping the temperature down helps keep the bit sharp and prevents the finished comb from giving off a strong smell. Fresh off the mill, the combs look a little rough....

After a quick rinse....

Each comb is held in place with support bridges. Here, I have cut them free.

Then wash away the debris.

The rough combs need to be sanded polished and flattened. I first start working on the outer edges and tips of the tines.

Here the outer edges and tines are smooth.

Next, I flatten the top and bottom sides. I check for flatness using a reference. This comb is not flat and needs to be fixed.

After a little work, it's flat.

At this point, the combs are starting to look nice.

Next, I round off every edge. The front (tines, viewed from the side) is rounded.

...and the corners...

Next, I painstakingly work on the inside of every tine. I make sure each one is shaped for comfort.

These tines are comfortable on your tongue.

I start the process of lacquering the tips of the tines. I apply many thin coats instead of only a few thick coats. I do this to ensure the lacquer doesn't chip or crack. My aim is that they last a lifetime.

This is after one coat.

After several coats...

If it's dry and it looks wet, it's done!

Next, I polish the sides and back of the comb. The last step is to flatten the comb one last time to ensure it's going to deliver peak performance.

Combs get wrapped up immediately and are ready to be shipped.

Mysterious embossing instructions - Can you see the light?

I offered some Mysterious Embossing Instructions which included a clue you can download and print out.

This video explains the clue I gave, my reason for offering it in this way and a demonstration of how I use indirect light and a three-dimensional view to make quick and effective work of embossing harmonica slots.

With this method, you get benefits similar to using a microscope and a light-table but avoid the respective disadvantages and limitations of those devices.

Mysterious embossing instructions

Embossing decrease the space between the reed and the edges of the slot. With higher tolerances can come better performance - the harmonica responds better and plays louder.

The thing about embossing is that so much can go wrong. Fixing the damage can take more time than it takes to do the actual work of embossing the slots.

So how to you "walk the line" to get maximum benefit without creating problems for yourself?

Some folks advocate special tools. Some use a light table. Others use a microscope - sometimes.

All those things can work well. But every method has its disadvantages.

For example, a fast-acting tool can overshoot the mark causing you to work against yourself. A light table only shows you two dimensions and as the reed passes through the slot in three dimensions, you can be left confused as to what you are seeing. A microscope can be overkill - you may not even need one if you have good eyesight. You certainly don't need to use magnification to do most of the work - if anything, you would want to shorten your view of the slot instead of zooming into one segment. But if you are over 40 years of age, using some form of magnification is probably good idea.

Let me share a secret with you: You can get top-level results using simple methods that don't rely on fancy technology.

How?

I'm not telling you. I don't make a habit of keeping secrets, but this is something I have never shared before in public.

I am happy to show folks the basics of how to tweak harmonicas and I have a strong preference for some methods, but there are may ways to get a task done. You don't need to know this secret to do a great job. This method's advantage is that it makes things easier and saves lots of time if you do it correctly.

Again, I'm not going to tell you what it is. I will, however, give you a clue.

Here it is. Print it out. (It's a way of looking at embossing.)

Contact me if you think you have it figured out. I'll let you know whether you are hot or cold. I'll add the most interesting responses to this page as they come in.

Good luck and don't hesitate to contact me!

2014/11/24 - Stephen C. described the way he holds the reed plate to "get a pretty good sense of what's going on in the space between the reed and the plate" and he's very close to what I describe!

2014/12/25 - Jaime G. wrote about "aligning tip edge with edge under rivet (to emboss) with a secure and efficient method."

EDIT: The mystery is over! My explanation can be found here!

Tweaking harmonicas: Measure what you change

This is about methodology.

I made yet another harmonica tweaking video.

Here's a video demonstrating some of the things that are straightforward to quantify so that you can make changes that have a measurable benefit.

Some of these things include:

Tuning: It's easy to measure the pitch of a reed and whether it's in tune with another reed. Play all the octaves available and listen for "beating".

Bending: Bend the 3 draw (or any other bend) with as little force as you possibly can. You will find a "blind spot" somewhere in the middle where the workload is handed off from the draw reed to the blow reed as you bend down. How much work is needed to "skip over" this blind spot can be felt, albeit subjectively; it tends to be more work on lower key harps. We learn to "skip over" this blind spot early on when we are learning to bend. A well-playing harp can be played with very little breath force without having to work hard around the "blind spot".

Reed shape efficiency: By playing a single reed using your lips on the plate off the comb, you can get sensory feedback on how easily the note responds, how much flow you need to make the note sound strong, and how loud the note is. A well-shaped reed will make the whole reed plate vibrate when you play it.

Reed shape efficiency (again): By bending the single reed's note down, you can determine if the reed is prone to squealing. That's a great indicator of how efficiently the reed is set up.

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