DACs and bass response?

Jitter affects bass quite a lot. Especially as most DACs have a phase lock loop that creates low frequency jitter. Bass should be neither tight nor muddy but articulate. Tight can be a jitter effect - it can be unwanted overtones. Jitter can easily be misconstrued as detail to the untrained ear.

Looking at the inside of the Aqua La Voce, it’s looks to me as it has a capacitor coupled output stage, as many owners are doing cap change mods to it.
Being an opamp based output stage on it from what I saw, it is very possible with a tech who knows what he’s doing to trim out any dc offset to make this a direct coupled output stage, remember for everything not just for bass the best cap is no cap.

Cheers George

Seems like my choice of words is not skillful. With the COS, the bass, whether electric or acoustic, was very evident. Although it varied from one cd to another, I never had to struggle to hear it. And it was well-focused, not dispersed with too much bloom as I used to hear from my old Jolida tube integrated.  With La Voce, the bass was simply not very present on the majority of cds I played. It seemed to be buried in the mix or recessed. I don't really know how else to describe it. 

I'm using an Ayre QB 9 DSD and I've added a Regen ISO with the the optional linear power supply. I replaced the fuse with a Synergistic Research Black and attached an Akiko Audio XLR tuning stick to the Ayre DAC. These tweaks have made my DAC sound (to me) more natural, more balanced and with a greater degree of presence. I never up-sample, as it isn't necessary nor is it preferable. 
Doing this would probably alarm many however, I've tailored these tweaks to my own hearing. I would however appreciate slightly faster bass with more melodic structure whenever I'm listen to music options other than classical music and so I'm considering the new Synergistic Research Blue fuse for the Ayre. Is anyone using the Blue fuse?

@stuartk 

I am not familiar with the La Voce, but it sounds as though it may not have had enough burn-in time. Could it be the case? Also, did you notice any significant difference between balanced and single-ended outputs?

Best,

Luiz