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. 
The Benchmark DAC2 or 3 is much better than the DAC1. I have owned all 3. None of them are warm but the 2 and 3 are not fatiguing and much better DAC's. I have the DAC3 now. 

A really great DAC that is a bit warm is the Gustard X26 Pro. It costs $1500 and is excellent. Do not let that price make you think is cannot compete with $5K DACs. A really amazing bargain. I use the DAC23B and Gustard in the same system.

A very neutral DAC that is like the DAC3 but cheaper is the Topping D90se. I like the DAC3 for sound (by a bit) and features (by a lot) but the Topping is 1/2 the price and will not add anything to the sound with uber detail. Also non-fatiguing.
I don't know DAC2, but I jumped from DAC1 to DAC3 - huge difference, in spite of my DAC1 updated with better op-amps.  Sound od DAC3 is fuller in the midrange being as clean/detailed as DAC1 was.   You should update it, if you're still in accurate camp.
@soix I appreciate the recommendation. I see that is an R2R dac. I have heard they have different kind of sound. Have you heard the Musician Draco?
@kijanki I have not owned a dac other than the Schiit Modi 3+ for a few weeks and a dragonfly for my iPhone for about a year. I do not have much experience with dacs. The dragonfly makes Tidal sound great. Especially with MQA over Grado SR 80 headphones. I don't know which camp I am in. The NHT speakers are very clear with a slight harshness in upper midrange every once in a while. Not much though. Enough that I wondered if a dac with some coloration would not be good for this particular set up. I read that Benchmark does not believe there is a big difference between their models, but users seem to think so. Maybe that's why I could pick up the DAC 1 so cheap. The 2 and 3 are out of my price range. Do you have any experience with the Bifrost 2? Thank you for replying.
@yyzsantabarbara Thank you for the recommendations. When I buy for myself I would like to keep the Gustard in mind. I read about the Topping in the forums. Many seem to like it. 
@severncreek No, I don't.  I would save for used DAC2 or DAC3.  Benchmark is high tech company, that you cannot go wrong with.  As for the camp - I've tried to apply my engineering background to make sense of electrical principles behind good audio reception, until I finally realized that audio is like a woman - supposed to be loved, not understood.  There is no right or wrong.  

I see that is an R2R dac. I have heard they have different kind of sound. Have you heard the Musician Draco?
Well, you said you were looking for something different and with some warmth or character. To me, the DAC 1 is the extreme embodiment of the delta sigma DAC signature, and R2R is pretty much the antithesis of that sound so seemed like a good option given what you’re looking for. The Draco is the cheapest well-implemented R2R DAC that I’m aware of and lies just north of your price target.  I haven’t heard it, but Musician’s DACs are getting very positive reviews so seems like a good bet.  In any event, it’ll almost certainly sound quite different from the DAC 1.  FWIW. 
Another DAC that would provide a different presentation (less clinical) would be a MHDT DAC. The Canary is ~$800 new. 
@soix I had been reading about R2R days and thought that might be the case. I just dod not have enough experience to generalize.  If I try another it will probably be an R2R to have a sample from the other side. Thanks for helping and for recommending the Draco.