glory,
Google this audiogon thread:
Quantum Science Audio light blue fuse; $71, what a bargain!
It’s one of the threads that the moderators took down for reasons some of us thought rather unfair.
I’m still working on getting my SR Purp, but I do have 2 QSA Light Blue, if this is the fuse you’re talking about. It is very good. And some say it is/was better than the SR Orange. To my rig it sounded fantastic for only $71 bucks each.
Is it better than the the SR Purp? Not according to oregonpapa, as he has compared the QSA Light Blue to the QSA Yellow at $213, and the QSA Yellow to the SR Purp at $200 and found them wanting compared to the SR Purp. And as others have mentioned here also.