Similar to "Kotsuzumi", it's lager and makes very hight note. They also call it "Ohkawa". It has the same structure as "Kotsuzumi", the difference is the tightness of "Shirabeo", it ties up Player holds it with left hand and puts it on left nee, then hits the "Kawa" straight with right hand.
Production technique is same as "Kotsuzumi", 28-29.5cm long, about 750g. There is "Tsuba" decoration engraving in the middle of "Doh". They also have "Kanname", the mark of engraving knife just as "Kotsuzumi".
Horse leathers put on both end of "Doh", about 23cm across in diameter. They are very thick and have no lacquer on. Different from "Kotsuzumi", have to keep them very dry to create extreme high note. Player puts assembled "Ohtsuzumi" on original stand in front of "Hibachi", a Japanese heating charcoal brazier, for The performance life is about 10 times because of the severity use. Very interesting matter comparing to "Kotsuzumi" that needs humidity and lasts for hundreds of years.
As same material as "Kotsuzumi", they use twisted hemp yarn.