Ich habe noch nie eine andere Aussprache gehört als "swop" (BE habe aber auch einige AE Freunde, bei denen klingt der Vokal leicht anders, offener, aber sicher nicht wie "swäp").

"Paul", e.g. here says "swarp" - roughly :-)

http://www.oddcast.com/home/demos/tts/tts_example.php?clients

edit: and so does Samantha, I'd say...

Sophil, in manchen Wörterbüchern wird eine eigene Darstellung von Lauten verwendet. Hast du mal nachgesehen, welche Transkription die amerikanischen Wörterbücher verwenden, in denen du nachgeschlagen hast?

I pronounce swap to rhyme with chop, but suspect I have a different vowel than the one Sophil refers to. I have never heard, however, an AE speaker use æ or ɛ. I can't imagine anyone pronouncing it to rhyme with chap.

I pronounce it as does Amy - and have never heard it pronounced in any other manner in AE.

Amy-Mimi, es mag auch meinem untrainierten deutschen Gehör geschuldet sein, aber ich finde, die Aussprache, die man sich bei Merriam Webster zu swap anhören kann, ist näher an "chap" als an "chop".

Oder siehst du das anders?

@sophil: I don't think it has anything to do with an "untrained" ear, but it may well have to do with not being a native AE speaker. I listened to the samples on MW, and while my pronunciation of chap differs somewhat from the one online, I still think that for me swap is clearly closer to chop than chap.

The old AHD I have indicates 3 vowels for these words (without using IPA) æ in chap, ɔ in chop and ɑ in swap. If you look at the pronunciation indicated by MW online, chop and swap have the same vowel sound, with chap again having æ. This accurately represents my pronunciation.

Perhaps you are reacting to some other quality of the vowel, such as length or tenseness, that is not distinctive for AE speakers but is significant for German speakers. It's been a bit too long since I had phonetics to be clearer on that. Maybe someone else can help.

Das (Cambridge) English Pronouncing Dictionary von Daniel Jones
hat für swap: [swɒp, AE: swɑ:p]

chop and chap are both pronounced differently in different parts of the English-speaking world, but wherever you are, swap rhymes with chop.

(It is not infrequently spelt 'swop', actually.)

Insome parts of the US, the vowel in words like cot (or swap) is pronounced the way British speakers pronounce the vowel in cart , with a long "ah" sound.

This has nothing to do with how swap is spelled and it would be a mistake to pronounce it with an /æ/ (as in cat) or a German <ä>.

is pronounced the way British speakers pronounce the vowel in cart , with a long "ah" sound.

see the link in #2