Gapping and profiling.
I had an interesting repair tonight that was a first for me. One blow note in the middle of the top octave on my G Seydel had a much slower tremolo rate than it's neighbors. In fact, the tremolo seemed to be missing at times. I had never noticed this before on this harp, but I had also never played this particular song before on this harp. The song was a soft and slow number that I usually play on a Suzuki because on the Richter tuned Seydel there is a missing note unless you move the tune up an octave (which is what I did). So I'm playing the high notes and it sounds sweet except when I had to hold this one note. I tried each reed by itself and they worked OK. That's when I noticed that when I started with only the bottom reed and then added in the top reed that the tremolo effect was good again. Not perfect but pretty close to the rate of the neighboring notes. So it seemed to be a problem with getting the notes going or getting them in sync, not a tuning problem. Also, playing the note hard seemed to bring the tremolo effect back. That may be why I never noticed it before. This was a soft tune.

After taking it apart I see the top reed has twice the gap (distance between the tip and reed plate) as the other reeds near it. The bottom reed also had a larger gap similar to the top. However, the bottom reed also had a curve to the reed. The reed curved up at the tip. The other reeds were pretty much straight. I know some blues harp players like to "profile" reeds (curve the tip up) for better response, but this reed was mostly curved just at the tip, and different than the others. So I used a small brass tool (from Andrew Zajac) to support the reed where the curve just began and pushed down the tip with a homemade tool (guitar fret with the ends rounded and smoothed) to straighten the tip to look more like the other reeds. (The curve seems to have resulted from the factory tuning.) After putting the harp back together the problem was actually a bit worse. I suppose the curve was compensating a bit for the extra gap in the other reed. Next I used the brass tool to gently lower the gap on the top reed until it matched the neighboring reeds. Success! I could now hold that note and play it softly as the song required.

In my experience most tremolo rate problems are cured by either learning to play better (operator error) or by cleaning (again operator error) or by tuning a reed. I thought I would share this experience since it was a bit different. The factory tuning was spot on. It was a gapping and profiling issue. Adjusting those resulted in a perfect tremolo rate. This whole job was done by eye and ear in less than 15 minutes. Each reed was adjusted only once. Maybe I got lucky. Or maybe just eyeballing a reed gap to match the neighboring reeds is close enough. Or maybe next time it will take me several adjustments and an hour.

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