A valve system for brass instruments comprising mechanically actuated rotary valves rotatably mounted in valve sleeves, and tube sockets for tubes which conduct the air flow in and out and for valve tube loops. The valve system has a milled valve block, in which a bore is arranged which runs through the valve system rectilinearly and with a constant cross section through the valve sleeves, into which bore bores open which run approximately at right angles to said bore and have the same cross section as the valve tube loops. The bores are connected to one another during valve actuation by way of the rotatable valve cylinders and bores arranged therein. The bores run approximately rectilinearly through the valve cylinder and correspond in terms of their cross section to the further bores, and the valve sleeves likewise are milled directly into the valve block.