Just a thought on running digital through the Io with volume control... With the volume control option, Jim includes a single switched high level input. So, the design accomodates an additional high level source, whether CD, tuner or other. To accomodate multiple additonal sources, one is faced with inserting a separate switch box or with swapping the interconnect among sources. I've chosen to do the latter in switching between CD or Tuner. Inelegant, but effective. And it may work for me only because I listen to vinyl 95% of the time anyway.
Also, keep in mind that the Io's second input inserts ahead of the last active gain stage. This means it avoids the issues that exist with a purely passive volume control set-up. I don't know if the Manley does this as well, or whether the Manley inserts directly ahead of the volume control in a purely passive arrangement. And, keep in mind that the volume control used in the Io is the same incredibly high quality volume control used in the Callisto line stage. Perhaps Fmpnd can shed some light on whether the Steelhead's design is similar or different. If different, that might account for his strong preference for the linestage with the Steelhead.
At the same time, I've also read Albert Porter's comments about preferring the Io and Callisto in combination to the Io solo. All I will add is that I'm using the Io Signature alone with a 0.4mv output cartridge, and the dynamics seem without limit. (Using the dual power supplies option does have an impact on dynamics.) If the addition of a Callisto linestage is even better, wonderful! But, the Io Signature with volume control and dual power supplies is pretty doggone incredible, too. I don't hesitate to recommend it to anyone who listens primarily to vinyl and who is willing to take a minimalist approach to inputs, outputs and other switchable features.
Also, keep in mind that the Io's second input inserts ahead of the last active gain stage. This means it avoids the issues that exist with a purely passive volume control set-up. I don't know if the Manley does this as well, or whether the Manley inserts directly ahead of the volume control in a purely passive arrangement. And, keep in mind that the volume control used in the Io is the same incredibly high quality volume control used in the Callisto line stage. Perhaps Fmpnd can shed some light on whether the Steelhead's design is similar or different. If different, that might account for his strong preference for the linestage with the Steelhead.
At the same time, I've also read Albert Porter's comments about preferring the Io and Callisto in combination to the Io solo. All I will add is that I'm using the Io Signature alone with a 0.4mv output cartridge, and the dynamics seem without limit. (Using the dual power supplies option does have an impact on dynamics.) If the addition of a Callisto linestage is even better, wonderful! But, the Io Signature with volume control and dual power supplies is pretty doggone incredible, too. I don't hesitate to recommend it to anyone who listens primarily to vinyl and who is willing to take a minimalist approach to inputs, outputs and other switchable features.