Well, I imagine a 7600k would boot up and run just fine with 1.5V RAM. I know Intel says you could damage the memory controller by doing so, but they also say the same thing about overclocking the CPU itself, and people don't have a problem doing that. I guess it's up to the individual whether they want to risk running Skylake/kaby lake with 1.5V ram.
Alternatively, you could under volt your regular DDR3 to 1.35V. Although it may not be stable at its rated speed then.