please help diagnose preamp problem

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Hello all,
I'm hoping to get help diagnosing a hum problem in my preamp going to speakers. It is a Dyna rebuild kit design. My understanding of tube amps is very limited but I did build this one and I have learned a lot troubleshooting, especially here and DIY Audio.
I am pretty confident it is not a signal grounding issue. The hum doesn't have the sound of an ungrounded signal but rather that of AC harmonics making their way past the transformer. If I had to guess I would say it is at both 60 and 120 Hz, a little buzzy but low and smooth. (I have rewired all the inputs and outputs with new twisted pairs, new jacks and gone over their grounds carefully as a precaution.)
I suspect the transformer but don't know how to test it without replacing it with a new one. The transformer itself emits the exact same tone making it's way to the speakers and it vibrates noticeably causing the heater tube to rattle intermittently on the PCB.
This is what I have done:
1. Dismounted the transformer, rotated it in every direction, suspended it away from the chassis, placed a metal tray in between it and the tubes, put a brick on top of it, and run the preamp while alternately removing tubes.
2. Run it without any inputs attached through several amps and speaker combinations, off of several outlets, (without safety, with safety ground, and GFI direct back to the panel.)
I have enclosed a picture to account for my lack of descriptive ability. This design was originally intended to have a phono section (left half of PCB) but I was given permission to omit that section. The phono tubes are in place to rule out their absence as a possible culprit.
Many thanks in advance for any help on this,
gary
Picture at: http://home.comcast.net/~garyworld/preampguts.jpg

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The Cable Cooker

Topic - please help diagnose preamp problem - gary hennemuth 17:43:26 01/30/07 (9)

More Info - Triode_Kingdom 23:20:31 01/30/07 (3)

Re: More Info - gary hennemuth 16:20:58 01/31/07 (2)

Sounds like PS - Triode_Kingdom 20:34:30 01/31/07 (1)

Re: Sounds like PS - gary hennemuth 11:12:53 02/05/07 (0)

Re: please help diagnose preamp problem - REL54 19:28:12 01/30/07 (4)

Re: please help diagnose preamp problem - gary hennemuth 22:56:37 01/30/07 (3)

Do you have the 10 ohm resistor in place? - Russ57 06:36:28 01/31/07 (2)

Re: Do you have the 10 ohm resistor in place? - gary hennemuth 16:45:59 01/31/07 (1)

Re: Do you have the 10 ohm resistor in place? - Ron Oehlert 05:21:02 02/01/07 (0)

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