Definitely, the output coupling caps can choke out bass if they’re too small. And you probably need more capacitance than you’d think given the usual 1 / (2 * pi * R * C) roll-off frequency calculation. I think my older Rogue Ares could have benefited from larger output caps (they were only 0.47 uF), for example. But plenty of phono stages do use more than ample capacitance for hooking into the typical preamp (50K - 100K input impedance). I think in many cases, rolling different makes/qualities of capacitor will have a bigger sonic impact than just going to a bigger value of same make - output coupling caps are one of the most critical components for "voicing" a tube amp. Also, using a SUT vs. the JFET MC stage will significantly impact the perceived bass response, while having nothing to do with the output caps (SUTs too are a critical component with a lot of sonic variability across makes). I tend to like the thicker, more impactful sound rendered by a good SUT, but this is very cartridge-dependent.