Operation confirmed. No cigarette smell. No rust. No scratch noise. Purchased new on December 8, 2025, from mima1919, who is also active on Mercari and other flea market sites, on a different flea market site. I suddenly changed equipment, so I no longer have a chance to use it. I only connected it once, so it's practically unused. There are scratches on the main unit's case, etc., from the time of purchase, but please understand that this is due to the design. This is a used item. Please understand and consider before purchasing. It works exceptionally well with digital devices, especially amp simulators. If you have any questions, please feel free to contact me. Shipping will be from the Yamato Transport sales office. This "OEP Line Transformer Box" was inspired by "Neve-kun." The only difference is that Neve-kun is a copy of the NEVE 1073's microphone input, while the OEP Line Transformer Box is a copy of the line input. In audio equipment, it is desirable for the input impedance to be twice the output impedance, or ideally more than 10 times. The output impedance of a microphone is around 200Ω, and the microphone input is around 1.2kΩ. Low line output signals are around 600Ω to 1kΩ, and line inputs are around 10kΩ. High line output signals are around 250kΩ to 500kΩ, and Hi-Z inputs are 1MΩ or more. Now, regarding Neve-kun, the input impedance is 1kΩ and the output impedance is 4kΩ. This is too low for line input and too high for output. It just sounds muffled and nothing like the silky sound of a NEVE with a Carnhill transformer. In that respect, the OEP Line Transformer Box is a copy of the line input, so you can enjoy the pure, silky sound of Carnhill without any muddling. It is absolutely NOT OK to pass phantom power through it. The transformer will be damaged. Switch the output destination's input impedance to 10kΩ if it's 20kΩ or more, and 2.5kΩ if it's less than 20kΩ. Using 2.5kΩ will reduce the volume by about 5dB. Adjust with the input level. Use 10kΩ for effects, multi-effects, amp simulators, Hz input terminals, and guitar amps, and 2.5kΩ for line inputs on audio interfaces and mixers.