You will probably overload the preamp. I always break in gear by just listening.
With the investment you have in Vincent and Linn Classic you should opt for one of these.
They work superbly, I have one and it's saved me countless hours while greatly improving performance.
It's only $79.95 and for top performance you can reinsert and burn in a couple of times a year.
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.
You're welcome Lew.
Another option I've used with the KAB is connecting it's regular RCA output to pin connectors to accommodate a tonearm.
Start with an old pair of "throw away" AV cables, those that came packed with VCR and such.
Cut the RCA connectors off one end and connect the two conductors (center and shield) to proper size pins or alligator clips.
Now the KAB can be run through the tonearm cable at phono cartridge mount point. Don't forget to connect the tonearm cable into the phono stage to terminate the connection.
With a CD player (or tuner) on repeat you burn in everything in the chain at proper EQ and voltage. I swap CD software frequently, varying from classical to pop and hard rock.
I've accumulated several hundred hours burn in a relatively short time. Makes a huge performance improvement and saves countless hours of wear and tear on a cartridge waiting for the wiring to reach 100%.
BTW, I put a new Vincent Pho-8 up against a new Pro-ject phono tube box II (my demo one was replaced under factory warranty after 1 channel got noisy) this weekend. The Pro-ject won out with better sound stage, realistic instrument sound and just overall more musical. I hope to upgrade the wall wart for the Pro-ject tube box. Would this one be a higher quality less noisy power supply?:
EA1050A-61 16V 4A 5.5x2.5x11mm $57.50
To follow up on my earlier post about the Granite Audio discs -- they output at suitably low levels for this application, like the KAB device. Which I expect is why the MC and MM discs are separate. The MM output is too great for an MC phono stage and you wouldn't want to accidentally play those tracks.