FS: Gustard X20u DAC w/ Dual ESS Technology Sabre Reference 32 bit ES9018 DAC chips, XMOS USB 384 kHz, DSD256, IIS: DSD512 (requires DDC, ex. SingXer SU-1). Includes remote control w/ extra batteries, stock power cord, allen wrench for top removal, original box, electronic owners manual, drivers, spare fuse, extra copper strips (for fuse bypass, see tweaks below)). New $870+ $60 tweaks =$930. Sale price: $300 plus shipping to US (16 lb.-19 in x 14 in x 7 in box shipped from 37912). Paypal payment (I'll cover goods & services fee). Tinnitus has severely restricted my music listening, so low hours on this excellent sounding DAC (approx.1,000 hr. over 5 yr.).

Good following on Head-Fi & AudioCircle:
https://www.audiocircle.com/index.php?PHPSESSID=66oan6cf7012e2qtr5n2ip0asu&topic=140663.0
https://www.head-fi.org/threads/gustard-x20-dac.780385/

Tweaks as outlined in http://tweakaudio.com/EVS-2/Gustard_X20_Mods.html added significant sound improvements over stock version. Specific tweaks per attached photos consist of EAR SD40AL (.040" thick w/ 5 mil aluminum) damping material (MichaelPercy.com) applied to capacitors & metal divider panels, twisted all wires, 3M 5030 emi/rfi absorbing material above transformers, replaced both transformer bolts & nuts w/ nylon versions w/ cardboard applied underneath. Fuse bypassed w/ copper foil wrap (note: stock spare fuse in holder can be used if preferred).