• The aforementioned Wiktionary.fr is normally my dictionary of choice, primarily because I always have it with me thanks to Aard Dictionary (aarddict.org). French Wiktionary is quite good in the pronunciation department; it’s the clarity of the definitions that occasionally leaves me wanting my Petit Robert.

• Antidote might be worth a serious look, and not just because it meets the pas as /pa/ criterion. Since it’s made in Canada it even indicates regional variants of pronunciations between France and Quebec when applicable. On the downside it costs €119, which is a lot more than a paper reference work, but I just noticed there’s also an iPhone app with only the dictionary for €15. I’d probably buy it if I didn’t have an Android phone.

NB The following screenshot is of Antidote 8 v4 as I don’t have Antidote 9 at my disposal. The new version should be much the same or better.

Not really an answer to the question, but I think that replacing /ɑ/ by /a/ and /œ̃/ by /ɛ̃/ is a mistake.

The abolition of the difference between /ɑ/ and /a/, and between /œ̃/ and /ɛ̃/ is advocated by the French education ministry to make teaching easier, but it is not that obvious when speaking to the random Frenchman. And more importantly it depends on 1) the French region, and 2) the word itself.

For example, I always make a difference between /œ̃/ and /ɛ̃/, but I hardly make one between /ɑ/ and /a/, except for the word “pâte” (pasta) which must be said /pɑt/ to avoid confusion with “patte” (paw).