Only if you are 100% certain the piece is in the public domain (composed before 1928 in the US) and you have robust antivirus software. Even then, PDFCoffee forces you through aggressive ad redirects.
The Guide to Finding Brass Quintet Sheet Music: Is PDFCoffee the Right Choice? pdfcoffee brass quintet link
However, as every professional musician will tell you, there is a dark side to this convenience. Only if you are 100% certain the piece
Even when the PDF is legitimate, the quality is often abysmal: the French horn
When you find a link and print your music, remember the physical setup. For the best sound, the French horn