“The L-9000 contains what Allnic immodestly claims is the world’s most sophisticated and highest-performing volume attenuator. Developed by Park over 20 years, it’s a fixed-impedance, oil-clutched, bridged-T mechanical attenuator with a range of 61 steps of 1.5dB each. Park claims that this attenuator operates linearly at virtually all volume levels, without channel imbalances or variations in impedance, and with superb sound quality.”
Review by Soundstage Ultra, May 2021
https://soundstageultra.com/index.php/equipment-menu/1031-allnic-audio-l-9000-otl-ocl-preamplifier