In 1904, the Manén family befriended the famous poet and novelist Ernst von Wolzogen and his family in Berlin. The relationship with the Wolzogen family was a close one and the fruit of mutual admiration. Wolzogen was so interested in Manén’s opera Jeanne de Naples that he commissioned a German translation for it and got the Frankfurt Opera House to premiere it under the title Der Fackeltanz in 1909. On his part, Manén returned the favour by composing the song cycle Canciones Alemanas Op. A-4, using poetry by Wolzogen and his wife.
After a long season immersed in the composition and premiere of his first two operas, Manén returned to the violin with greater intensity, facing very difficult compositions. The technical level that he had already developed at age 20, was truly extraordinary for the time. In November, 1904, thanks to the patronage of Goldschmidt’s nephew Pancho, Manén experienced a true triumph at the “Hochschule für Musik” in Berlin, performing twice one of Paganini's most difficult works; the Variations on the theme God save the King. The musical press was full of praise and Manén started receiving a number of contracts that would have been unthinkable only months before. His name began to spread within musical society and Pancho Goldschmidt decided to represent him professionally. In 1905 he began by performing in Lodz (Poland) and then did an extensive tour of Germany: Erfurt, Weimar, Leipzig, Dresden and other cities.
In 1906 the reviews from the German press regarding Manén reached the “Revista Musical Catalana”, and they were translated and included. In Leipzig they assured that "[...] yesterday Joan Manén showed to be a master without equal and unleashed storms of applause [...] In Paganini's art it must be recognized that today Mr. Manén is in first place among all violinists.” (Arthur Smolian, Leipziger Zeitung No.40, 2-17-1906). Furthermore, it was said that "his phenomenal technique, of great clarity, together with an absolute purity of sound, already ensure the favour of the public. But we appreciate even more his deep musicality, his famous bow strike and his magnificent cantabile [...] I consider Manén, as truly the greatest violinist of today, and he seems to me, even more so than Kubelík, a Paganini redivivus. "(Dr. V. Lederer, Der Signale Leipzig, February 14 and 21, 1906). Other newspapers in Berlin, Dresden, Düsseldorf, Cologne, Hannover, Danzig, Weimar, Ponen or Baden, confirmed with similar phrases Manén’s immense success in Germany during the winter. At the end of 1906, during a brief stay in Barcelona, ??he gave two important orchestra concerts, conducted by Joan Lamote de Grignon, at the “Teatro Principal” for the Grané Auditions, where he performed the Double Concerto by Bach with violinist Joan Massià. Manén also continued composing and some of his works appear in his concert programmes under various pseudonyms; according to his memoirs (Mis experiencias), he used pseudonyms to protect himself from possible bad reviews.
From 1907 onwards, Manén toured Europe continuously, including countries like Russia and Finland; the latter country invited him annually until the outbreak of the first war. The same year he premiered his Symphony Nova Catalònia in Germany, with the “Plauen Philharmonische Orchester” conducted by Max Werner. The symphony was performed again in 1911 by the “Dresden Gewerbehauskapelle Orchester”. In June, 1907, Manén gave three recitals at “Teatro de la Zarzuela” in Madrid in the presence of King Alfonso XIII, who invited him to a reception at the Royal Palace where he met the writer Jacinto Benavente and the composer Tomás Bretón. At the end of 1907 the Royal Dresden Opera prepared the performance of Manén’s opera Acté, conducted Ernst von Schuch, as part of their opera season. The cast featured some of the best voices of the day such as the soprano Marie Wittich, the tenor Karel Burian and the baritone Karl Perron. The premiere took place on the 24th of January, 1908 with unanimous praise from the musical press. This success was one of the most important during Manén’s lifetime and the triumph helped him establish himself as an outstanding composer, especially in Germany. One of the reviews of the time stated the following: "Has Dresden discovered in the young Manén a Spanish Richard Strauss? If we compare Manén’s original melodies in his opera Acté with the brilliant contrapuntal polyphony of Strauss – which the Spaniard boasts as well in a fantastic and ardent way – we could find many points of contact such as advanced harmony, descriptive capacity, the power of attraction and the sonority of dissonances.” The surprising and lasting success led to over twenty representations in Dresden and later representations in Cologne 1910 and 1914.