ok to break in phono preamp w/ non lp source?

You will probably overload the preamp. I always break in gear by just listening.
Alan

They work superbly, I have one and it's saved me countless hours while greatly improving performance.
http://www.kabusa.com/preconlp.htm

Hagtech makes a similar device for breakin:

Inverse RIAA Filter

LOL, good one Marakanetz... except that many manufacturers will disclaim their warranty obligations to the extent damage was caused by owner abuse.

Putting a line-level signal into a phono input might be deemed as such. It certainly would not accord with the instructions provided with the unit.

Both those inverse RIAA filters attenuate the signal so I see no problem with using them.

I have not used one myself but they look interesting.

Albert, Thanks so much for letting us know about that KAB device. It seems to be quite a bargain at the price. I just ordered one.

As to the OP's question, the output of a CDP would drastically overload the input of any MC phono section and probably most MM phono sections as well, as many others have noted. (The latter typically have a much higher upper limit for signal voltage going in compared to the former.) However, I don't think it would do permanent damage to a tube type, maybe to a SS type. I do wonder whether you would get the break-in effect that you seek. Bottom line: don't do it.