FWIW. This may not relate to anything going on here. Direct drive
turntables all have, sometimes substantial,rumble. The difference
from a rim drive turntable is that the direct drive turntables, such
as the SP 15 rumble at such a low frequency as to be inaudible. I do
know of situations where they used up all the headroom in direct
coupled amplifier, with just the rumble. I believe the Thorens is a
belt drive table. That's what made me think of this
Not knowing your equipment, I don't really know if something like
this could be going on here. As I said, FWIW.
>Although my problem with the transfer of 78s are nearly over, it would seem
>I am not quite out of the woods yet and I would really appreciate any
>explanations or suggestions on why it is that all tracks on CDs, other than
>those produced from the Technics SP-15 are playing OK on a laptop. I am now
>in a situation where the Technics tracks are playing perfectly everywhere,
>including the desktop computer. However, a CD made of assorted tracks
>produced by other sources, including vinyl on a Thorens, played on the
>laptop plays fine other than when it comes to the Technics tracks.
>Evidently, it is the only piece of equipment left which is not happy with
>these recordings and distorts when playing them.
>Like Malcolm, I record these tracks in stereo, something that has not given
>any problems in the past on any machine. Volumes are set O.K., no clipping.
>Before recording, checks are made with all equipment involved and there are
>no hints, either visibly on meters or audibly through headphones, that there
>are any extraneous noises such as hums or crackles. No distortion can now be
>detected at any stage during previews before transferring.
>For me, the most puzzling thing is that recording singles from the 50s on
>the Thorens proves to be fine when played back on the laptop, substituting
>the Thorens with the SP-15 to record 78s from the 50s (not that date really
>matters) produces distortion on the laptop. The laptop, by the way, is a
>I appreciate a comment made earlier from the group that I shouldn't worry
>too much about one piece of equipment being happy with this but this part of
>a mastering process for commercial production and all common possibilities
>of machines (and a lot of people listen to CDs in their laptops) that would
>be used to play this on must pass the test.
>Any explanations or suggestions greatly received.