Both versions put out an honest 90/180 stereo/mono watts. This due (primarily) to the new 490V power transformer.
The V uses non-lead components and solder so it can be sold in the EU.
The volume controls on the IV worked only with the SE inputs anyway. Using the balanced inputs has a couple of advantages, but the most important one is that the splitter/inverter circuit (12AX7 tube V-1) is not necessary and therefore another source of noise is out of the signal path.
Sonically they are both the same, and the stereo unit vs. two mono units sound the same too, but will provide more headroom (afforded by separate power supplies for EACH channel) should if you have LARGE speakers which you play LOUD ;-)
The V uses non-lead components and solder so it can be sold in the EU.
The volume controls on the IV worked only with the SE inputs anyway. Using the balanced inputs has a couple of advantages, but the most important one is that the splitter/inverter circuit (12AX7 tube V-1) is not necessary and therefore another source of noise is out of the signal path.
Sonically they are both the same, and the stereo unit vs. two mono units sound the same too, but will provide more headroom (afforded by separate power supplies for EACH channel) should if you have LARGE speakers which you play LOUD ;-)