What did a good 10 MHz clock do for your Gustard R26?

I don't understand why people buy external clocks. The dac itself should already come with an excellent clock. Not sure I like the idea about adding an additional box to address a deficient clock within a dac.  Plenty of higher end dacs have excellent clocks.  Maybe you're stuck with a deficient dac that should be replaced.

I don't like separate dacs and I have a couple but I purchased a lumin x1 which is a streamer/dac and that's working out really well.  I don't have to fiddle with extra connections and tormenting myself with a feeling I need to consider a new dac. Also the internal wiring if done well to connect a really good dac capability is far superior than dealing with additional interconnects, etc 

I'm not a fan of integrateds, but in these couple of areas above it would seem to me justifiable

I don’t understand why people buy external clocks.

Well we’ll just add that to the already huge and growing pile. I sense yet another inane thread coming our way. 🤪🙄

The Gustard C16 external clock has an OCXO with its own power supply. The R26 has a crystal but not at the level of an OCXO, and it's rare to find a DAC with a separate power supply for the clock. That's part of the benefit of an external clock.

I may have changed my mind. You should probably ignore me because I keep changing it, but I listened to another DAC this weekend (the Denafrips Terminator 1), and tried another USB cable between my Aurender and each of my DAC options. I also considered that whatever I do I'll probably have this technician friend (Igor in New Jersey) modify the DAC, and in the case of the PS Audio he can do the well-known transformer and VOCM mods, which will probably increase the resale value as it's well regarded. I decided that the PS Audio has many strengths (such as faithful/beautiful timbre and musicality) and its only weakness is a bit lacking in oomph and resolution compared to the Denafrips or my previous DAC, the modified X20 pro. Well, Igor can fix that. The R26 and Denafrips had more weaknesses with no guarantee they can be fixed. So I think the winner at this point is the PS Audio! And off to the shop to get the transformer and VOCM mod, plus a power supply component upgrade. Anyway that's the plan. I keep changing it, but I'll know for sure at least by the time the R26 has to be returned to Amazon.

Rolled Off Highs

Depending on placement and application quantity, ERS is known to roll off the highs, soften and add vagueness to the presentation.

I'd try removing it, let it re-settle in and listen again.

Don't have time to read all of these right now but I can give a quick heads up on a couple of things. Don't judge your clock after the first day. They can take 2 weeks to reach optimum operating temperature. Should never be turned off. And unless you're going for a big bucks i2s (HDMI) cable like the Tubulus, the 12-in long blue jeans HDMI cable easily beats the others I have tried costing up to $100 or so