He continued his studies from 1990 to 1991 at the Sofia Academy of Music with Lesa Koleva and from 1991 to 1993 at the Hochschule der Künste Berlin with Herbert Brauer.
He appeared as the Landgrave in Tannhäuser in 2002, Titurel in Parsifal in 2004, King Marke in Tristan und Isolde in 2005, and Fasolt in Das Rheingold and Hunding in Die Walküre in 2006.
[3] Youn has appeared in concert at the Accademia Nazionale di Santa Cecilia in Rome as well as at the Wiener Musikverein, the Vienna Konzerthaus (e.g. in March 2010 in Gustav Mahler's Eighth Symphony) and at the Salzburg Easter Festival.
[7] He has given recitals with his piano partner Helmut Oertel, such as in the summer of 2007 at the Margravial Opera House in Bayreuth and in the autumn of 2007 at the Oper Frankfurt.
He has worked with conductors such as Christian Thielemann, Mark Minkowski, Fabio Luisi, Michael Gielen, Myung-Whun Chung, Zubin Mehta, James Levine, Horst Stein and Thomas Hengelbrock in opera and concert as well as in CD productions.
[7] He appeared in recordings of Le nozze di Figaro, Così fan tutte, Don Giovanni and d'Albert's Tiefland with conductor Bertrand de Billy.