The Flatness Tool™ and Reed Plate Claws™ Q&A


What are these tools?
These tools are used to make harmonica combs and reed plates fit together perfectly. Air leaks and empty spaces between the plates and comb cause power and volume loss, slugish response and bad tone. The instrument performs best when all the parts “become one” and vibrate at the same frequency.

Are these tools the same as the F Tool™ and the Comb Tool™?
Mostly, yes. The biggest change is the Reed Plate Claws. I innovate and find new and better ways to get the job done all the time.
The Flatness Tool™ and Reed Plate Claws™ replace the F Tool and Comb Tools; I am no longer offering them.

Will you ever stop innovating and improving your products?
Before I die? No. After I am dead, probably.

What’s the difference between the F Tool and the Reed Plate Claws?
The reed plate claws are used as a pair whereas the F-tool is used alone with a pair of pliers. The Claws offer you a little more control and a little more sensory feedback as you re-shape the reed plate because you use your two hands to act together instead of squeezing pliers.

What’s the difference between the Comb Tool and the Flatness Tool? (They look the same!)
The Flatness Tool has the same precision as the Comb Tool. The difference is the Reed Groove which allows the tool to fit between the reeds on a reed plate. With it, you can use the same tool to measure the flatness of the comb as well as the reed plates. The Comb tool doesn’t have this groove and can only be used with combs.
The F-Tool uses a separate reference bar to measure between the reeds. The reference bars are very small and easy to lose!

Do you sell the tools separately or as a set?
I offer these tools as a set so that you can make every component fit together perfectly.

I already have the F-tool and the Comb tool, should I upgrade?
It’s up to you. I got excellent results using the Comb tool and F tool for years. They are still excellent tools that get the job done very well. You should decide for yourself if the new improvements are something you can’t live without.

How do I use these tools?
Instructions are provided and I am working on an up-to-date video. As with all my tools, you get email support, too. Ask me anything.

Tuning offsets

It's a bad idea to tune a harp using only numbers. The exact pitch of a single note played on a diatonic harmonica will vary by a few cents depending on a few things including your breath force, your embouchure and your attitude. So relying on numbers alone is very inaccurate.

That being said, when you are tuning chords to sound in harmony, you need to know where approximately the pitch needs to be so that you can tune each reed to pair up with other reeds using your ears.

Some intervals are more important than others. When dealing with Standard Richter or altered tunings, here is a list of some of the intervals you will have to tune.

Sometime you will want to sacrifice harmony so that the single notes are in tune - this is a compromise as in "compromise tuning".

I can think of three things than help me decide whether to compromise or not:
1- How far away from ET you need to raise or lower the pitch.
2- How close to ET you or the person for whom you are tuning the harp would want each note to be.
3- How much the Just interval in question contributes to harmony (how good the interval sounds).

I have listed how important the harmony is for certain intervals so that it can help you decide which way to go on a case-by-case basis.

If the interval is not listed, don't worry about it and tune it close to ET. Its "Just" tuning doesn't provide any contribution to harmony to be of concern because these intervals will always sound dissonant.

Here is the Interval, the Ratio of the pitch of the tonic to the pitch of the interval, and the Offset which is plus or minus some cents from tuning it to zero on your tuner.


Major second(*) - ratio 9:8. Its offset is about +4 cents.

This interval doesn't add very much to the harmony of the chord so don't worry too much about it. Six draw in Standard Richter is this interval. It's not too important relative to the tonic of the 1-2-3-4-5-6 draw chord (two draw) but it is relevant to the 4-5-6 chord which is a minor third. In that case, the 6 draw is a fifth of the tonic (four draw). Fifths on the other hand, are very important.


Minor third - ratio 6:5. Its offset is about +16 cents.

A minor triad will still sound pretty strong even if the third is tuned to ET so this is not very important. It's a good place to compromise.


Major third - ratio 5:4. Its offset is about -13 cents.

This interval is very important to a major triad. Try not to compromise with this interval.


Fourth(*) - ratio 4:3. Its offset is about -2 cents.

A fourth is the same interval as a fifth but in the opposite direction. So try to not compromise here.


Fifth(*) - ratio 3:2. Its offset is about +2 cents.
The Fifth implies the tonic. It is a very strong harmony when it is in tune. Try to not compromise here.


Minor sixth - ratio 8/5. Its offset is about +13 cents.
This interval sounds good when in harmony. But I don't have a lot of experience with altered tunings using this interval.


Major sixth - ratio 5:3. Its offset is about -16 cents.
This is used in Powerbender tuning on both the blow and draw plates and provides a very nice sounding interval. But -16 cents can sound pretty flat. Again, you choose as to whether you will use the interval or chord more than you want to keep the melody note in tune.


Minor seventh - ratio 7:4. Its offset is about -30 cents.
This is the traditional sound of 7-Limit-Just Intonation tuning where in Standard Richter the 5 and 9 draw are tuned very flat. When in tune, playing any combination of draw holes together will imply the tonic note.

But -30 cents is too flat for melody notes to sound in tune. The usual compromise is to tune the 5 and 9 draw sharper and only play the 1-2-3-4 draw major chord excluding the 5.


(*) A final note about Fifths, Fourths and Major Seconds (in standard Richter): Since these offsets are very close to ET - only within a few cents - you will not really have to compromise. But I suggest you focus on getting them accurately tuned; close isn't good enough! When these intervals are in harmony with the tonic, they will make that interval sound very very strong. But it has to be "bang-on" because the window of opportunity is small.

Even if you are only a fraction of a cent off, it's a missed opportunity to my ears...


Are you new to tuning a diatonic harmonica? Here's a great place to start:

Altering Standard Richter to Powerbender

"What's the best tuning temperament for POWERBENDER?"

My favorite altered tuning is Brendan Power's Powerbender tuning.

To me, the most important feature of the diatonic harmonica is the sound of bent notes. Powerbender offers you powerful, juicy draw bends on all ten holes. There are no blow bends, nor are there any overdraws to play.

All of Powerbender's draw bends are dual-reed bends which means both reeds collaborate to make the sound. You get a much stronger and smoother sound than you get from single-reed bends like overblows and overdraws or half-valved bends.

PowerBender holes 1-2-3-4 are the same as Standard Richter. Ten reeds are re-tuned to provide the note layout.

You can order pre-tuned Powerbender harps but sometimes the fastest and most economical way to go is to convert a Standard Richter harmonica. The conversion to Powerbender is a pretty big job. Some notes need to be lowered by three or four semitones.

Here is a visual aid to the modification:

These note changes can have an impact on how well the harp responds but this is nothing that can't be fixed with a little reed adjustment.

But since reed adjustment will impact tuning, where do you start? The best strategy is to make the coarse tuning adjustments before you do reed work.

Here is a sensible method for getting this done with the least amount of wasted time and effort:

Alteration checklist:
1- Swap blow/draw reeds 9 and 10.
2- Correct factory defects.
3- Perform coarse tuning adjustment. Lower pitches using BluTak or Solder. (See semitone offsets in red)
4- Perform other customizing and improvements including reed work.
5- Perform fine tuning. Identify Major Chords for Just or Compromise tuning. (See scale interval to help you achieve harmonic tuning.)

If you tune your instrument for the major chords, Powerbender layout offers you some new intervals (fourths and sixths) to deal with. These intervals are not part of Standard Richter tuning so you may have never had to tune them before. Thirds, Fifths and Sixths can make the harp sound very powerful when tuned in harmony.

But those notes can sound out of place as melody notes if you have sensitive ears and play in many different positions.

Should you even worry about temperament? Should you just tune everything to ET? It depends on your needs and preferences.

If you play in First, Second and Third positions almost exclusively you may benefit from tuning these intervals in harmony. If the melody notes of most off-the-shelf harmonica are too far out of tune for your ears, go for ET with Powerbender.

Final note: Brendan Power uses half-valving (or even extra reeds in his X-Reed harmonicas) to achieve chromaticism. I just don't connect with half-valving.

I prefer a strong connection with a responsive harp. I prefer playing the missing notes as overblows (there are no overdraws on Powerbender!).

You can have it any way you like.

Best lighting for reed work (and everything else)

Are you having trouble seeing all the small details that are important to reed work, embossing and most of everything else? The trouble is likely how your work space is lit.

This is what my workbench looks like from above. This is me sitting in front of a white piece of paper with a reed plate on it:

Ideally, light should be coming from directly above, like this:

If you are having trouble seeing things, it's likely that your lighting is behind you or off to one side. You will always struggle to see what it going on like this:

Light and shadows help us see what's happening. A small detail like this can mean the difference between viewing the reed passing through the slot or seeing no detail at all. I hope this helps you avoid some frustration.

My favorite comb thickness

Matthias Hohner nailed it over a century ago! There are a lot of things about the Marine Band 1896 that are perfect by design. Admittedly, mass-production takes its toll and not every one made is perfect.

But all the details he settled on seem to be bang-on.

I get asked about the perfect comb thickness a lot. I offer regular, thin and thick combs. Each has its own strong points and weak points. The thinner the comb, the better the response but at some point the tone will sound "thin".

Thick combs can offer deeper tone, but responsiveness suffers and a thick comb can make the harp feel sluggish.

The good news is that you can get pretty much the best of both worlds without having to make a huge trade-off.

The thickness of the stock Marine Band comb is right in the middle of both these features.

Here's a representation of these effects. This is not an evidence-based representation, rather a subjective display of what I have observed about the effect that comb thickness has on the instrument.

The thinner the comb, the better the response:

The thicker the comb, the deeper the tone:

Put the two graphs together and you see there is a nice range centered at 5.8mm where both features are available at the same time:

Custom harmonica guide

Click on the image to download the PDF file.

7-Limit Just Intonation

7 Limit Just Intonation is when all the notes of the draw plate are in harmony.

The recipe to achieve this is laid out as a table of offsets but you cannot tune a harp to be in harmony using only numbers. No tuner is accurate enough - not to mention because of our embouchure, we skew the offset when we play individual notes.

This video is pretty much an audio-only example of what 7-Limit Just Intonation tuning is.

7-Limit-Just-Intonation favors the major chords over tuning the single notes. Any three consecutive holes played on the blow plate will play a major chord. Any three consecutive notes played on the draw side will play major chord tones but anything above hole five will include the flat-seventh and/or ninth. When tuned to 7-limit-Just Intonation, these chord tones are in harmony and imply the tonic.

You can call it a harmonic, a difference tone or a combination tone. When the frequencies line up perfectly, the effect is that the sum is greater than its parts. You get a louder more powerful sound.

See my other videos on tuning - as well as my Premium video on tuning using an analog strobe tuner - to learn how to tune using your ears to help build accuracy.

Sneak peek at my Premium Videos

I offer 11 Premium videos on my USB drive in addition to over 30 of my best YouTube videos.

My Premium videos go into unprecedented details - no one has every shown this stuff before!

My tools are made to order

I make my tools by hand. These have been cut, polished and sharpened. Ready to be packaged.

Dark Combs™ for Lucky 13 combs

I now offer Dark Combs™ for Brendan Power's Lucky 13 harmonicas.

Order them here: Other models including Marine Band 364, 365, pre-MS Meisterklasse, Seydel Big Six, Easttop 008

I strongly recommend you obtain and use The F Tool to straighten both the blow and draw reed plates. These are fine harps, but they suffer a little more from the difficulties associated with mass production than a higher quality harp.


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