This auction is for my AT630 moving coil cartridge step-up transformer. It is designed to match a low-impedance moving-coil phono cartridge to the input stage of a standard moving-magnet phono pre-amplifier. As its a passive device, it will exhibit lower noise than an electronic moving-coil pre-amp.The AT630 features wide bandwidth & low distortion and is suited for a moving coil cartridge with an impedance of up to 20 Ohms. I used this one with an AT30E cartridge for years and it sounded great.The transformer design features a triple perm-alloy shield to greatly reduce electromagnetic coupling from external sources of interference. The phono ground connections on the output side are isolated from each other avoid hum loops. A ground connection to the shield is provided at both ends, so that the tonearm ground can be connected through to the amplifier. Audio Technica Specification :Input impedance : < 20 ohms.Output impedance : 47k ohms.Frequency response : 15Hz to 100kHz I believe the turns ratio to be 1:10.In order to demonstrate continuity, I measured the input and output resistances (not impedances) of the windings. The table below shows the corrected figures after subtracting test lead resistances of 1.9 ohms (for the input measurements) and 0.9 ohms (for the output measurements) : Input windings Output windings Left Right Left Right 2.5 ohms 2.6 ohms 561.6 ohms 566.2 ohms Thanks for looking.