Break In Time..just being on...or music played ?

I believe it needs music playing through it. Yes, I think it's mainly the capacitors, but they need to be cycling (storing and releasing energy) to break in.

I just had a great experience using a Granite Audio MC phono burn-in disc to burn in my new phono preamp. I would not have believed the results had I not heard it for myself.

I wouldn't think that you'd need to turn your amp on, just put a cd in and have it repeat through the preamp for a couple of days. That should do wonders. I've found that it makes a bigger difference depending on how many, and how large the caps are. Usually the more caps the more burn-in required, the bigger the sonic difference.

Cheers,
John

Eldartford, no, IMHO.
That's why I said that turning the amp on was optional.
He could just run the cd through the preamp, with the amp off.

When I was burning in my phono stage, I played the Granite Audio CD on repeat 24/7, when I was not listening to vinyl (amp and preamp were off). Obviously when I was listening, I listened to the cartridge with the amp and preamp on. That's how I could tell how much it opened up, even after just a couple of days of running the cd.
FWIW, the phono preamp I bought was the BAT VK-P10SE w/ Super-Pak. Those huge oil-can caps take quite a few days to burn in right. It was amazing how it sounded after a week of burn-in compared to right out of the box. Night and day, so to speak.

John