Alternate to Benchmark Dac 1?

Over the last few weeks I put together a system for my mother. NHT C-1 speakers, Rega Brio 2017 amp, and  a Benchmark Dac 1 as a source. The Dac 1 is better the the Schiit Modi 3+ I tried before it. If I were buying for myself, I could try this and that for a long time. However, since I am buying it for her, I will have limited opportunity to audition things. The question I have is what would be a good alternative to the Benchmark? As I understand it, the Benchmark is known for being accurate, while others are considered less accurate but are like for certain qualities they have. I was able to get the Dac 1 for $365. What would be a good alternative at $600 or less  (new or used) that would represent a different sound? The benchmark is very clear, lacks distortion, and made sense of Zooropa and other albums which have a lot of complex mixes. I was impressed. I would just like to try something that may have a bit more warmth before we settle on something. She is 72 and will probably have this from now on. By the way , the NHT C-1 speakers seem to very neutral, like the Benchmark. I guess I'm thinking something with a little "warmth" or "character" might be worth a look.