Gain versus volume

Which one sounds better?

If your preamp was a lot better than your Rhea, you might want to use the lower 62db setting on the Rhea and turn up the volume on your preamp. If it was the other way around you might want to do it differently.

The distributor will be able to tell you what the recommended gain setting is for your cartridge. To further complicate things, if you have a Calypso, there are a couple of user accessible internal jumpers that lower/raise the gain by 12db that can impact on how your preamp/Rhea sounds.

I have a XYZ for which it was recommended I use the highest 75db setting but I'm not sure if that was for balanced cables. That setting picked up too much surface noise for my liking and I've been using 68db balanced instead. Love it.

If I understand your question correctly: The "volume" knob on your preamp IS a "gain" control. Hence- There is no actual difference since the are both really amplifiers(one a pre-amplifier and the other a pre-pre-amplifier). As Mr V stated: The one you choose to increase your "gain" through can impact your signal greatly.

Having the ability to select gain on your phono preamp gives you the flexibility to match the gain of your vinyl rig with that of other sources feeding your preamp (e.g. a cd player) so that whether you are listening to vinyl or cd your preamp volume control will operate in the same region. Keep in mind that setting the phono preamp at the higher gain setting may introduce more residual noise from that device which will depend on the downstrean gain of your system. I assume that the Rhea is quiet regardless of the gain setting chosen.