The conventional sarod is a 17 to 25-stringed lute-like instrument — four to five main strings used for playing the melody, one or two drone strings, two "chikari" strings and nine to eleven sympathetic strings. The design of this early model is generally credited to Niyamatullah Khan of the Lucknow Gharana as well as Ghulam Ali Khan of the Gwalior-Bangash Gharana. Among the contemporary sarod players, this basic design is kept intact by two streams of sarod playing. Amjad Ali Khan and his disciples play this model, as do the followers of Radhika Mohan Maitra. Both Amjad Ali Khan and Buddhadev Dasgupta have introduced minor changes to their respective instruments which have become the design templates for their followers. Both musicians use sarods made of teak wood, and a soundboard made of goat skin stretched across the face of the resonator. Buddhadev Dasgupta prefers a polished stainless steel fingerboard for the ease of maintenance while Amjad Ali Khan uses the conventional chrome or nickel-plated cast steel fingerboard. Visually, the two variants are similar, with six pegs in the main pegbox, two rounded chikari pegs and 11 (Amjad) to 15 (Buddhadev) sympathetic strings. The descendants of Niyamatullah Khan (namely Irfan Khan and Ghulfam Khan) also play similar instruments. Some of the followers of Radhika Mohan Maitra still carry the second resonator on their sarods. Amjad Ali Khan and his followers have rejected the resonator altogether. These instruments are typically tuned to B, which is the traditional setting.