Moving Coil Transformer Model MCt made by CarverSpecifications for the Carver MCt Moving Coil TransformerDimensions: 6" wide, 2" high, 3" deepWeight: 1lb 11 oz.Gain: 24 dBSignal-to-noise-ratio: Greater than 100 dB IHF A-weightedImpedance: 3.9 ohms, 39 ohms, 110 ohmsFrequency Respone: -3 dB at 3 Hz and 80 kHzWhat are moving coil transformers?They are passive devices (with no power supply) that "transform" the excess current from the moving coil cartridge into voltage, which can then be amplified (and equalized) by the (MM) phono stage of the preamplifier.Read more about how they work and why you should use them at the following websites:http://www.high-endaudio.com/RC-Step-ups.html#IntIn the following web article I feel they give a pretty good explanation of what these trasformers are and why you may want to use one. Most of the reading is still over my head as I am not an audiophile but I am strating to learn more and more as each component comes into my shop from one of my many clients.From what I can tell the main reason for using a Moving Coil Transformer (Step up Transformer) is if you have a moving coil cartridge on your phono but your amp or pre-amp does not have a MC (moving coil) phono stage so it cannot handle the the signal properly and your big dollars you spent on that new cartridge are wasted.There is a lot of reading that can be done on these moving coil transformers and I suggest you start at http://www.6moons.com/audioreviews/stepup/primer.html