I've had experience with used Denon amplifiers, and they can be a great investment if you know what to look out for. Denon is known for reliable and durable products, but with any used gear, there are several considerations:
Age and Model: Check the specific model and its age. Older models may lack some newer features like HDMI connectivity or advanced surround sound capabilities.
Physical Condition: Inspect for signs of wear and tear like scratches, dents, or rust. These can indicate how well the unit was maintained.
Functionality Test: If possible, test the amplifier to ensure all inputs/outputs work properly. Pay attention to any irregular noises or overheating.
Capacitors: On older models, inspect or inquire about the capacitors. They can wear out and affect sound quality or lead to failures.
Sound Quality: Denon amps are known for their warm, detailed sound. Older models might lack some crispness compared to newer models due to technology advances in digital processing and components.
Comparison to newer models will largely depend on personal taste and the context of your setup. If you're set on a Denon and the unit is in good condition, it can provide excellent value for your money. You might also want to check audio forums or reviews for any particular model insights. Good luck!