MC Step Up Box S3

The MC Step Up Box S3 is a passive step-up transformer placed between a moving-coil cartridge and a phono preamplifier. MC cartridges deliver roughly a tenth of the output of moving-magnet types, and the transformer raises the signal voltage through its winding ratio. Because it needs no power supply and does no active amplification, the voltage increase comes with a matching decrease in current. The maker positions it as a low-noise, low-distortion alternative to a dedicated MC phono stage and recommends it with a good MM phono preamp, especially a tube one.

A switch on the back selects between two cartridge impedance ranges, 10-40 Ω and 40-150 Ω, which gives 21 dB or 24 dB of gain at 1 kHz. The transformation ratio is 1:16 and the recommended load is 47 kΩ / 100 pF. Frequency response is 10 Hz to 55 kHz within ±1 dB.

It connects with one pair of gold-plated RCA phono inputs from the tonearm cable and one pair of gold-plated RCA outputs to the phono preamp. The housing is solid aluminium, handmade in Europe, and comes in silver or black.