I recently purchased an Okto Research dac 8 stereo that is surprisingly good when used as a pre into my amp. This wasn’t as much the case with my previous dac. Even though it still presented well enough on its own, doesn’t hold a candle to the Okto overall (whether as dac or dac/pre). Really does boil down to design, quality of output stage and voltage.
I still overall prefer using my SPL Elector before the Okto, which brings more nuance, timbral delicacy/transients and depth of stage to the presentation. Still very curious what a different amp might bring in a direct configuration, however.