HQP NAA- NUC7CJYH, Akasa fanless case: 

Plug & play set-up... connect USB cable to DAC, ethernet cable to network for wired connection only (wi-fi not attached). Initiate HQPlayer from server & select NAA. Excellent condition. Akasa case 3 mo.old, NUC 2.5 yrs. old but very light use (4 hr. per week max).

$325 invested. Sell for $125. Paypal fees & shipping insured Priority Mail to lower 48 states included in asking price.

HQPlayer Network Audio Adapter- USB thumb drive w/ HQP naa-420-x64.ramfs.7z image (if inserted: automatically boots to NAA login upon start-up)- https://www.signalyst.eu/bins/naa/images/

Intel NUC7CJYH/ J4005 w/ 8gb RAM (G.Skills Ripjaws DDR4 2400) & 120gb Crucial BX500 SSD w/ Ubuntu 20.04 OS installed (if NAA thumb drive removed, boots to owner-preferred OS)- https://ark.intel.com/content/www/us/en/ark/products/126135/intel-nuc-kit-nuc7cjyh.html

https://www.intel.com/content/www/us/en/products/sku/128992/intel-celeron-j4005-processor-4m-cache-up-to-2-70-ghz/specifications.html

JC Newton fanless Akasa case- runs cool 29 deg. C initial > 42 deg. C max after 2 hrs. run time w/Ubuntu OS, psensor, activity monitor processing (see pics). Anything under Intel CPU max temp of 60C considered safe operation. NAA operation w/ thumb drive & no OS will be far less demanding. https://www.akasa.co.uk/update.php?tpl=product/product.detail.tpl&no=181&type=Fanless Chassis&type_sub=Fanless NUC&model=A-NUC42-M1B

NUC stock power supply & case included. Note: Silver linear power supply w/ red cable shown in pics is "sold" & not included.