I'm selling this because I'm using a different MC transformer and no longer need it. It has been opened, but it's unused. * **\[For MM/MC Preamps]** The AIYIMA T3 PRO is our first phono preamp equipped with four op-amps and supports various resistance adjustments. It is also our first phono preamp compatible with both MM/MC cartridges. * **\[Front Gain Control]** Compatible with both MM/MC turntables, allowing gain settings from 0 to 39dB to be switched on the front panel. * **\[Variable Impedance Settings]** To accommodate all MC cartridges, it offers 8-step variable input impedance settings (not suitable for MM cartridges). This provides customers with a wide range of options to customize the sound characteristics to their preference. * **\[Unique Design]** The rational heatsink design prevents excessive heat generation, and the use of aluminum/metal casing not only enhances aesthetics but also prevents vibration and electromagnetic interference, resulting in excellent sound quality. * **\[Professional Phono Preamplifier]** The AIYIMA T3 PRO MM phono preamp only supports MM/MC phono single input (other audio signal inputs are not supported). The RCA audio signal output of the T3 PRO can be directly connected to active speakers or a home audio amplifier. The high-quality T3 PRO preamp, compatible with MM/MC, will reproduce analog sources clearly. * Model Name: T3 PRO * Type: MM/MC Preamplifier * Accessories: Instruction manual, QC certificate, power adapter Thank you for looking.