Edward N. Bilbie studied violin in Berlin for three years starting in 1888. He wrote a memoir of his career in 1921, which includes descriptions of some of the virtuosos of the time.

I heard De Ahna play the Beethoven Concerto with his own cadenzas. He was a clear, full-toned artistic player with flawless technique and delightful style. He gave the concerto a flavor I have never heard duplicated. It was perfect, yet a little different—a little nicer than usual, even the best. There was no imitation of anyone, no apeing of Joachim, yet it was quite as fine I should say. His cadenzas were as fine as I have heard excepting Kreisler’s. This was about 1890, and he died soon after. He was a big man and had a peculiar appearance, due to what seemed to be a sardonic grin and to hairs straggling all over his face, reproducing a peculiar effect, but rather humorous, not repelling. In the quartette his tone rivaled that of Joachim.

Edward N. Bilbie, Experiences of a violinist at home and abroad (Pittsburgh: Manchester Printing Co., 1921), 31.
Emanuel Wirth and Heinrich de Ahna, 1890