What can you say about the Ref 10, wow! Yes it retails for 30k but what an amazingly musical piece of gear. At the pinnacle of the Audio Research food chain this two piece is a statement in tube refinement and is known for its ability to send chills when listening to your favorite recordings. Think you have heard your favorite pieces, prepare for the best. This unit was re tubed in 2017 and every internal part inspected. We have the paperwork from AR. You will be hard pressed to find a more perfect used example. Very low hours since the re tube as my client downsized to a smaller integrated amp based system.