Pronunciation of the phonetic symbol /ʌ/

Solution 1:

In general, /ʌl/ and /oʊ/ are not pronounced the same.

Vowels before the /l/ sound are prone to merging with other vowel sounds. Most of these vowel mergers occur in some accents, but not in others.

Related to this, in some accents, the /l/ sound itself may be "vocalized", turning into a semivowel or glide like [w] or [ʊ].

So it's not too strange that the ul of consultant and the o of so sound the same to you. But this is not considered to be the "standard" pronunciation of words like consultant, because many speakers still use different pronunciations for ul and o.