My Univibe hums

[warioblast]

Hi guys,
I upgraded my forum vibe http://classicamplification.net/fv/default.htm with a 186C28 Hammond transformer and I have a hum / motorboating problem.

There is a slight hum when the pedal is connected. With the cancel switch disengaged it gets louder as the LFO kicks in, and even louder when switched on. More volume = more hum. Speed & intensity 'control' the motorbating.

I lifted the earth connexion from the IEC socket and it didn't changed a thing. I measured my Qs voltages and they were OK. I have 17.50V after the diode.  I was worried I messed up with the board because I change the values to the Honey specs.

Here's when it gets tricky. I decided to power the pedal with my Voodoo Lab Pedal Power, using a DIY cable and alligator clips. I fed the circuit with 18.5V right after the diode. THE VIBE IS QUIET AS A VIBE CAN BE. The good news is I didn't screw up the board and the debugging won't involve flipping the board.

With the transformer back in, I switched the primary wirings, it did nothing.
I wil try to disconnect the status LED, move the transformer around, though my build is relatively tight.
And after that I'll be out of ideas.

[warioblast]

I'm about to give up.  :(
I tried different bypass wirings, deconnecting the LEDs, the cancel switch, changing ground wires locations.
I took the transformer out of the enclosure, untwisted the primary wires, changing the orientation of the transformer, moved it farther.  :evil:
It didn't change a thing.