I've had these since the early 80s and every so often I'd try other headphones but always kept going back to the Sigmas.
I only took 39 years but I found what they wanted: a Rega Saturn and a low powered tube amp.
The amp is a Motorola pull which was redone following an old Bob Carver schematic, a different transformer and the addition of individual channel volume controls and a normal headphone jack.
The Sigmas sounded pretty bad through a Stax tube amp but the energizer/tube amp combination is a winner.
I finally discovered just how good these old Sigmas are (normal bias, not Pro).
The band on the Sigmas broke when I dropped them but I was able to repair it with an acetone/ABS slurry and then made up a jig to heat the plastic up with a heat gun to get them to take the right shape again.
