These are wonderful sounding strings, sadly let down by poor quality which is unusual from Pyramid. For such an expensive set of strings, you espect the quality to match the prince but sadly not in this case.
I've had three sets of these, the first was fine - the second (like another reviewer on here) snapped the A octave string (wound 19) on first tuning. Unfortunately, Pyramid / Thomann don't seem to supply single replacement flatwound strings, so I had to substitute from another manufacturer who did (Thomastik).
I recently restring with the 3rd set, and once again the A octave snapped. It was snapping mid way along the string, and the windings had unravelled. This time, I decided to contact Pyramid directly, who kindly sent me two 0.19 flatwounds out of courtesy. The first snapped on install at the tuner, the second snapped half way again.
Whlist I've had zero quality issues with Pyramid's other offerings, these sadly don't meet those same standards. They weren't a 'bad batch' as all the sets were sourced at different times - it seems the wound 19 isn't up for being an A octave.
An expensive mistake I won't be making again.