OP - understood, apologies if I came off as harsh. I believe in full disclosure and that those with a professional interest can and should comment but should always disclose their industry interests.
On your question, best I’ve owned is the Nagra Tube Dac. It’s a case study in implementation - you can get newer digital but it’s hard to find better implemented power supplies / analog output stage...that stuff does not get old. It does deserve a proper preamp and good server / transport.