Thom, I'll raise you 20 and call it 100, but basically I think you're correct. Whether it's 80, 100, or 125 really depends on the cartridge's suspension material, the ambient temperature, and the VTF.
Speaking of VTF, I now recommend breaking in cartridges at about 10% more than their max. rated VTF (up to 100 hours or so) By doing this you won't hurt anything but you gain two things: First, the break-in may take a bit less time (which doesn't really matter a lot -- you're going to play records anyway ;--) but second, and much more important, is that if you want to finally run your cart at max VTF (which a lot of folks are beginning to think sounds/tracks best with MCs) then by overflexing the suspension just a wee bit in the beginning, you can be sure that it will be operating at its rated compliance, even at max VTF.
As for your second statement:
"I have never experienced a cartridge that didn't show its nature after 10 and wasn't stable (meaning substantially broken in) after 25."
I just can't agree with that. In fact, my experience has been the opposite, i.e. I've always been "dissappointed" with my (new) cartridges until right around 50 hours when they begin to change just enough that I realize they're not always going to sound like shreiking banshees!
All this could change (i.e. maybe NO break-in period) if/when better(?) suspension materials come along -- already, Transfiguration advertises that their new suspension material is impervious to changes in temperature and humidity.
.
Speaking of VTF, I now recommend breaking in cartridges at about 10% more than their max. rated VTF (up to 100 hours or so) By doing this you won't hurt anything but you gain two things: First, the break-in may take a bit less time (which doesn't really matter a lot -- you're going to play records anyway ;--) but second, and much more important, is that if you want to finally run your cart at max VTF (which a lot of folks are beginning to think sounds/tracks best with MCs) then by overflexing the suspension just a wee bit in the beginning, you can be sure that it will be operating at its rated compliance, even at max VTF.
As for your second statement:
"I have never experienced a cartridge that didn't show its nature after 10 and wasn't stable (meaning substantially broken in) after 25."
I just can't agree with that. In fact, my experience has been the opposite, i.e. I've always been "dissappointed" with my (new) cartridges until right around 50 hours when they begin to change just enough that I realize they're not always going to sound like shreiking banshees!
All this could change (i.e. maybe NO break-in period) if/when better(?) suspension materials come along -- already, Transfiguration advertises that their new suspension material is impervious to changes in temperature and humidity.
.