This is an interesting thread. I also have very strong relative pitch.
One problem I have had a lot of trouble with--and it was mentioned above by Ghostrider45--is off-center holes. It doesn't take much. This effect is most noticable when constant pitch instruments like the piano are playing.
The degree of pitch change increases (grows worse) as the needle approaches the center of the record since the fractional linear speed change causing this increases as the distance to the axis of rotation becomes smaller. So what can be a disconcerting suspicion at the begining of an LP grows into cause for leaping up in alarm to inspect for what the heck is going wrong.
I need to discard a few percent of the records I purchase due to off-center holes...some of them otherwise pristine Shaded Dogs (sob sob).
I have toyed with the notion of actually offsetting the axis of some of my rare LPs by enlarging the hole on one side to compensate. Haven't tried it yet, though.
A slightly bent spindle would also result in this type of periodic change in pitch.
To see if this non-axial rotation is a problem, put a piece of opaque tape on the lid of your TT as a visual reference. Then watch very closely to see if the arm and cartidge are moving slightly in and out as the record plays. It really doesn't take much (depending on how sensitive your are) and it can be hard to see without a fixed visual reference.
I am not that experienced in TT's but find SME's, Basis, and ClearAudio to be very acceptable as regards speed control. Unfortunately, they are also very expensive.
One problem I have had a lot of trouble with--and it was mentioned above by Ghostrider45--is off-center holes. It doesn't take much. This effect is most noticable when constant pitch instruments like the piano are playing.
The degree of pitch change increases (grows worse) as the needle approaches the center of the record since the fractional linear speed change causing this increases as the distance to the axis of rotation becomes smaller. So what can be a disconcerting suspicion at the begining of an LP grows into cause for leaping up in alarm to inspect for what the heck is going wrong.
I need to discard a few percent of the records I purchase due to off-center holes...some of them otherwise pristine Shaded Dogs (sob sob).
I have toyed with the notion of actually offsetting the axis of some of my rare LPs by enlarging the hole on one side to compensate. Haven't tried it yet, though.
A slightly bent spindle would also result in this type of periodic change in pitch.
To see if this non-axial rotation is a problem, put a piece of opaque tape on the lid of your TT as a visual reference. Then watch very closely to see if the arm and cartidge are moving slightly in and out as the record plays. It really doesn't take much (depending on how sensitive your are) and it can be hard to see without a fixed visual reference.
I am not that experienced in TT's but find SME's, Basis, and ClearAudio to be very acceptable as regards speed control. Unfortunately, they are also very expensive.