The Granite 657 has volume control on it's tube output. The solid state output is fixed, however. But, you do get the flexibility of being able to go with the sonics of either.
Also, variable attenuators the likes of which from Scott Endler (which I own) and EVS Ultimate Attenuators can turn any CDP, tuner, tape player, etc. into a component with volume control. They can also be used at the other end of the chain, the power amplifier. Go with whatever is more convenient - signal purity is maintained as only one high quality resistor comes into play.
Also, variable attenuators the likes of which from Scott Endler (which I own) and EVS Ultimate Attenuators can turn any CDP, tuner, tape player, etc. into a component with volume control. They can also be used at the other end of the chain, the power amplifier. Go with whatever is more convenient - signal purity is maintained as only one high quality resistor comes into play.