Guess you didnt quite read the first post TS wrote properly. Refer below.
Definitely the bass. Could be the jack, or the wiring inside. Go get it checked.
lol I did read it, at least 3 times to see if I missed any details before posting, maybe you didnt?
He said 2 symptoms:
Problem 1:
Unwanted distortion on practice amp when volume is high.
My Answer: maybe the amp speakers are blown or ripped.
Problem 2
Bass does not work in studio.
Fact 1: his bass works at home but not in studio amp. only distorted.
Fact 2: studio bass works on studio amp but not his own bass
Fact 3: studio bass is usually passive, his bass is active
My Answer: Since his bass works at home practice only with distortion, it means that the bass works. Usually studio amp routes\configs differently to passive vs active bass because of different output of active and a passive bass. Most bass amps has a High and low input. he did not specify where he plugged the bass. Meaning he should take another look at the studio amp, or ask help from owner of studio. besides, we all know that studio amps are most of the times crappy.
I am pointing to amps as the problem simply because home practice amp produces a different symptom as the studio amp. meaning if it was a problem with the bass it self, it would have produced the same symptom no matter what amp you use. get it?
and jack problems does not produce distortion on high volume FYI. jack problems would produce crackling sounds or no sound at all on any amp used.
AND OUT OF TOPIC:
I don't know why you need to put down other people, we are all trying to help this person.