As far as I know, the words like: run or under (letter: "u") are pronounced as:

1) British: /rʌn/
2) American: /rən/ with the schwa sound

The above according to the page: https://www.lexico.com/en/grammar/key-to-pronunciation

Now I wanted to confirm that in the dictionaries.

1) Merriam Webster dictionary shows: \ˈrən\
2) All other show: /rʌn/

The difference between: ʌ and ə is really subtle ... if any ... In my opinion the recording on Merriam Webster dictionary says more like: ʌ than ə

In: ə the mouth is slightly opened and relaxed
In: ʌ is more open than for: "ə"

How should that really be pronounced? Where can I find the recording so that I could hear the difference?

As far as I know, words like run or under (letter: "u") are pronounced as:

1. British: /rʌn/
2. American: /rən/ with the schwa sound

The above is according to the page: A Key To English Pronunciations — Lexico/Oxford

Now I wanted to confirm that in the dictionaries.

1. Merriam Webster dictionary shows: \ˈrən\
2. All other show: /rʌn/

The difference between: ʌ and ə is really subtle ... if any ... In my opinion the recording on Merriam Webster dictionary says more like: ʌ than ə

In: ə the mouth is slightly opened and relaxed
In: ʌ is more open than for: "ə"

How should that really be pronounced? Where can I find the recording so that I could hear the difference?

As far as I know, the worlds like: run or under (letter: "u") are pronounced as:

1) British: /rʌn/
2) American: /rən/ with the schwa sound

The above according to the page: https://www.lexico.com/en/grammar/key-to-pronunciation

Now I wanted to confirm that in the dictionaries.

1) Merriam Webster dictionary shows: \ˈrən\
2) All other show: /rʌn/

The difference between: ʌ and ə is really subtle ... if any ... In my opinion the recording on Merriam Webster dictionary says more like: ʌ than ə

In: ə the mouth is slightly opened and relaxed
In: ʌ is more open than for: "ə"

How should that really be pronounced? Where can I find the recording so that I could hear the difference?

As far as I know, the words like: run or under (letter: "u") are pronounced as:

1) British: /rʌn/
2) American: /rən/ with the schwa sound

The above according to the page: https://www.lexico.com/en/grammar/key-to-pronunciation

Now I wanted to confirm that in the dictionaries.

1) Merriam Webster dictionary shows: \ˈrən\
2) All other show: /rʌn/

The difference between: ʌ and ə is really subtle ... if any ... In my opinion the recording on Merriam Webster dictionary says more like: ʌ than ə

In: ə the mouth is slightly opened and relaxed
In: ʌ is more open than for: "ə"

How should that really be pronounced? Where can I find the recording so that I could hear the difference?