This paper presents a new Epstein frame optimized for high frequencies and high flux densities. The design philosophy and test results at high power frequencies are presented. The frame achieves high frequency and high flux density performance because of reduced number of turns and reduced number of samples, while using standard 25-cm Epstein samples. Some of its technical advantages over the current Epstein frames and the single sheet testers are less samples' preparation time and better material representability, respectively. Four lamination types were tested: 0.0250-in (0.64 mm) M36 and cold rolled motor lamination, 0.0184-in (0.47 mm) M19, and 0.0140-in (0.36 mm) M45. The results obtained show good agreement with the core loss data provided by the steel manufacturers measured using the old frames at 200, 300, and 400 Hz. Results at 600 Hz and 1.0 kHz are also presented for the M45 and M19 samples along with the test bench used.