Alternative tuning approaches for the qanun thus also exist. Turkish music theorist Ozan Yarman has proposed, for example, an academical 79-tone temperament for the expression within tolerable error-margins of Maqamat / Makamlar / Dastgaha at all pitch levels, that was implemented by the renowned late luthier Ejder Güleç (1939–2014) on a Turkish kanun. Likewise, the late Swiss-French qānūn performer Julien Jalâl Ed-Dine Weiss (1953–2015), who was critical of the tuning deficiency of Eurocentric octave divisions in approximating just intervals, is known to have conceived, since 1990, a number of prototypes that were entirely based on low prime-limit or simple integer ratio Pythagorean and harmonic intervals; which were once again built, on instructions from Weiss, by Ejder Güleç.