Wow, thank you all for your replies. It has already helped me a lot.
I was very surprised recently to hear a sample of the /ɨ/ sound, which is said to be one of the Polish phonemes. I knew of course which Polish sound it was, but the sample wasn't it. It was a sound no Pole would ever produce speaking Polish.
Yes, I know that feeling. It often confused me a lot and made me question my own hearing abilities.
Keep in mind though that /ɔ/ is relatively hard to find in the two major English dialects, because in
RP it's closer to /o/ and in American English to /ɒ/ or even completely replaced by /ɑ/.
Does this mean that a native American speaker could forget about /ɔ/ and always say /ɒ/ or /ɑ/ instead, or did I misunderstand you here?
ii) I don't understand the problem, because they are indeed quite similar.
Sorry, I read the sentence a couple of times, but I don't know what you're trying to say. Do you mean, "I do understand the problem?"
The real problem is that /ʌ/ is used to represent a sound that varies a lot between English varities.
In
RP and California, the vowel is actually /ɐ/.
Oh, thank you so much. This is exactly the sound that I hear and use when uttering a word that supposedly has /ʌ/ in it.
In Texas and Ohio, it's /ɜ/.
The Wikipedia article you linked to says that this is
[t]he most common realization of the vowel transcribed as ‹ʌ› in American English.
I've never realized that. Is the /ʌ/ in blood, flood, mud, etc really realized as the same sound as /ɜ/ as in German, Germany, worry, .. in most of America?
Code:
I recommend forvo.com for this
Thanks! 
Try to learn the phonemes in context, surrounded by other phonemes. When you have heard and said ebb, deck, fetch, red, deaf, leg, bell, gem, ten, rep, mess, mesh, bet, rev, fez, and also some minimal pairs - bet/bit, better/bitter - then you will have a clear idea of /e/
Good idea, thank you, too. I will do that.