Now that you simply mention it, the first two tracks seem to deficiency reduced bass, (other than a bass drum strike just before the fade out of Custard Pie). But then “In My Time of Dying” seems to have some extra bass… not sure what was going on listed https://led-zeppelin-gold-record11964.blogstival.com/49102331/the-definitive-guide-to-led-zeppelin-gold-records