Dynaco ST-70 vs Mark 3

Is the sound quality better in a ST-70 or a Mark 3?  Other than the ARC ST-70 mods, are there any specific mods that significantly improve the sound of either one?  






Sound quality is always subjective. The Mk IIIs have a bit more power, and the benefit physically separate channels (no crosstalk), plus each channel has it’s own power supply.

VTA (Tubes4Hifi.com) has some mods for Dyna amps, that I found to be significant upgrades over the stock Dyna 70s.