User manual YAMAHA TP-129C

[. . . ] In the case of use by young children, we recommend proper guidance be given by a knowledgeable adult. Disregarding these warnings or misuse may result in death or personal injury. [. . . ] The head was partially tuned before leaving the factory (tuned to a certain pitch) however, the procedure described below should be used to tune the timpani to the pitch you want to play. the standard striking point is shown below. The standard striking point lies at distance B from the kettle edge, which corresponds approximately to 1/4 to 1/3 of the distance between the kettle edge and the center of the head (A). Sound is lower than the tuning note Go to step 2. â· Sound is higher than the tuning note Loosen the tuning bolts by the same amount in the order shown below. When loosening the tuning bolts, always loosen them by double the desired amount, and then return (re-tighten) them by half. When the sound lies within 1 halftone below the desired pitch after loosening the tuning bolts (repeatedly, if necessary), proceed with step 2. Tighten the other bolts little by little (by about 1/16 to 1/8 of a turn) until the sounds at the corresponding striking points match the pitch of the highest sound. please note that tightening one bolt also raises the pitch at neighboring and opposite tuning bolts. Thus, after tightening the tuning bolt with the lowest sound, again check the pitch at the other tuning bolts before tightening the tuning bolt with the next lowest pitch. Loosen all over-tightened bolts according to the procedure described in step 1. Repeat steps 2 and 3 until the head is tuned to the desired pitch. [. . . ] When the head is slightly tensioned and its surface looks wavy or shows dents, it is time to replace the head with a new one. Place the new head with the hoop on the kettle. [. . . ]