I think you're on that right track by investing some money into a DAC, a tubed DAC or any DAC for that matter will make vast improvements in your system.
I must admit that I'm not familiar with your brand of DIY Speakers, but if you're happy with them, then it's a non-issue, but this may be another area that I would focus on. You may want to consider a more refined speaker, an older pair of Sonus Faber comes to mind, I've always felt that they match really well with Rotel.
I think your good with the Rotel Separates for now, as I've always enjoyed their sound as well.
Let the journey continue....
I must admit that I'm not familiar with your brand of DIY Speakers, but if you're happy with them, then it's a non-issue, but this may be another area that I would focus on. You may want to consider a more refined speaker, an older pair of Sonus Faber comes to mind, I've always felt that they match really well with Rotel.
I think your good with the Rotel Separates for now, as I've always enjoyed their sound as well.
Let the journey continue....