How can I further improve the sound of my Audio Research with the right tubes?

With Audio Research, the sound can often be improved further when the tubes are not only technically suitable, but also carefully selected. In high-end units such as Reference 6SE, Reference 10, Reference Phono 3SE, PH9 or Reference 160M MkII, types like 6H30Pi, 6550, KT120 or, depending on the generation, E88CC / 6922 play an important role. For better sound, selected tubes with high stability, low noise and a balanced tonal character are recommended. S4A tubes are especially interesting for clean reproduction, a quiet soundstage and fine resolution.