A printhead reservoir assembly has at least one reservoir to hold ink. The assembly includes an outlet plate having siphon vents to allow air to exit an ink path, a manifold plate having at least one manifold to channel ink and manifold outlets to corresponding to the siphon vents, a jet stack having an array of jets to transfer ink out of the printhead reservoir assembly to a printing substrate and jet stack outlets corresponding to the siphon vents, and a circuit board between the jet stack and the manifold plate to operate the jet stack, the circuit board having outlets corresponding to the siphon vents.