Although effective power will be lower into a 12 ohm load compared to 8 ohm or lower as is typical with most speakers these days, the Zus are high efficiency speakers, meaning they go louder with fewer watts, and are designed to present an easy load (12 ohm) for most any amp to drive compared to most modern speakers with impedances of 8ohms or lower.
They should work very well with most any low to moderate power amp, including 100w SS, but be a particularly good match to the 35 w/ch tube amp.
They should work very well with most any low to moderate power amp, including 100w SS, but be a particularly good match to the 35 w/ch tube amp.