TAD 150 Pre Amp transformer died

Try Mercury Magnetics. If they're still around, they used to rebuild transformers or might have a matching replacement.

That preamp as well as TAD amps were made my a Chinese company called BEZ. Paul of TAD would then finished them out with some finishing steps.....

The transformer is most likely a BEZ and they still are in business and sell transformers. I bet you can take the old one out, take a picture and jot down the specs, then email BEZ for a replacement. I heavily modified a TAD 60 and have emailed BEZ thus this knowledge.

http://www.bezdz.com/engindex.html

The Tad 150 was made by a Chinese company called Audcom. I believe Bez made the amps for Paul

BEZ did make the amps for sure.

Here's an email I got from BEZ this morning:

Sorry this pre amplifier is not our product so we can’t repair.

We wish to help you but we only make EI core transformers.

Best regards
Zhi Huang
BEZ team

Hoping Mercury Magnetics can help.

Thanks so much for the replies Czarivey, Grannyring and Metman.
Any further thoughts please let me know.