RE: Damage
I tested my home-made US machine by US cleaning the whole record, then stopping the motor and blasting the bottom third for 2 hours. I reasoned that the first cleaning should get rid of the gunk, and the 2 hour blast should eat away the vinyl if anything would.
Then I played the record, expecting a change from good to bad every second or so. I heard no difference, using ESL's and a front end to match.
I tested my home-made US machine by US cleaning the whole record, then stopping the motor and blasting the bottom third for 2 hours. I reasoned that the first cleaning should get rid of the gunk, and the 2 hour blast should eat away the vinyl if anything would.
Then I played the record, expecting a change from good to bad every second or so. I heard no difference, using ESL's and a front end to match.