DACs and bass response?

@georgehifi : yeah; I am not at all mechanically minded, so what you you offer is, indeed, "sound advice"!  Thanks for the pic. 

In general I found that there is a trade of between mid/high to low dynamics  and not only in Dacs, gear that sounds very detailed and 'sweet' (strong at mid and high) doesn't peoduce strong punchy  bass and in contrary gear that has accurate  and tight bass tends to be less detailed and musical at the mid/high section. 
In general I prefer to sacrifice a little bit at high/ mid to achieve strong and tight bass .

Replacing capacitors mounted on a board are a bit tricky and best left to someone with experience. Point to point circuits are fairly straightforward. Don't ask me how I know.

@kalai: Point taken!