VTB9045 Input Transformer EXTREMELY sensitive...

I've got a preamp that's giving me grief.  It's a 1290 and one channel is buzzy and has a lack of low end.  I've swapped the output trafo and it checks out ok, but in my testing discovered that the VTB9045, when tapped with a screwdriver, is EXTREMELY loud.  Could this be the cause of my hum and lack of low end?  I've built these input trafos into a lot of things and have never seen a faulty one, but I'm sure it's possible?

Any help much appreciated!
Thanks,
Sig

Pulled the trafo out and wired straight across, the low end is back...which to me signifies that the trafo is bad.  Yes?

yes, could be a bad transformer.  you've checked all your wiring on the transformer pins?  also possible that the transformer itself is incorrectly pinned.  can you swap in another VTB9045?

ed

I have used thousands of them and have a had a few bad ones. Try opened it up and resolder the wires to the pins, have helped me in a few cases.