What is an "EQUAL-TINED"(tm) Disc?

Because musical combs in most disc musical boxes such as the Regina 15.5" box often have 2 or 3 tines tuned to the same critical notes, there can be many ways to punch out a particular tune on a disc without changing the actual musical notes played. The chart below is for an Antique Regina 15.5" Disc (#10279 - The Sweetest Girl in Dixie). Each set of colored rows represents either 2 or 3 tines tuned to the same particular note. It is important to note that some authorities have in the past suggested that tines within a set are actually tuned slightly differently ON PURPOSE, and that the person laying out the music must take this into account. I do not believe this to be true for most common music boxes in the 15" size range, largely because a study of hundreds of old discs (primarily Regina, but also Polyphon, Imperial Symphonion, and Olympia Discs) has revealed a nearly universal, fixed logic for laying out the music: USE THE OUTERMOST TINE OF A SET WHENEVER POSSIBLE. Nearly all the old discs used an inner tine only when an outer one wasn't available because it had just been struck.

Refering to the table below, we see, for instance, that the original disc uses tine #42 for the D above middle C sixteen times, and uses the inner tine, #41, only once.

Although I have not seen any written evidence, I believe the original manufacturers used this "Outer First" hole-punching logic to assure better accuracy. Remember, the further out a note hole is from the center of a rotating disc, the less will be the timing error resulting from a slight positional error.

The "downside" to using this method is that certain tines of the comb get used alot, while other tines hardly get used at all. We've already seen that D-42 gets used 16 times, while D-41 gets used once on Regina disc #10279. Note also that A-69 is used 6 times, A-70 12 times, and A-71 30 times.

My belief is that modern production capabilities greatly increase the accuracy of punching, so that what little may be gained in accuracy from using outer tines, is far outweighed by the uneven wear caused to the musical comb.

This is why HensTooth(tm) Discs offers a choice of "traditional" punching logic, or it's proprietary
EQUAL-TINED(tm) punching logic on all its discs.

EQUAL-TINED(tm) punching logic eliminates the bias for outer tines. Notice in the chart below that, for this disc, WHEN EQUAL-TINED(tm), D-42 is used 9 times, D-41 8 times, and the three A's (69,70,71) are now used an equal 16 times each.

The Main Point:

Equalizing the use of similarly-tuned tines across the music box comb eliminates excessive wear and stress on certain tines, resulting in less chance of breakage, and less 'detuning' of the tines because of wear.