[drummerwill]

Solder slingers will love this story.
  About a year ago I built this 6SN7/6SL7 Phono/Linestage preamp using some traded Electra-Print Linestage/ Headphone outputs. Sounded great but the left channel had a slight hum. I tried all kinds of tricks, Resoldered grounds, Stars ... everything. Then just decided to live with it for almost a year.
  A few weeks ago. it hit me the OPT was next to the Power transformer. So I rotated the OPT and Whoaooo, that did it.
   It might be a keeper!

   http://pg.photos.yahoo.com/ph/wjrive1@sbcglobal.net/detail?.dir=/485a&.dnm=7d1d.jpg&.src=ph

  Have fun!
   Willie

[Scott F.]

Nice job Willie. Yer gunna have to bring to teh next gathering

Hey, I wonder if rotating the transformer in Deadfish's humming bastard might do the trick too? I noticed the B+ mains were loosley twisted too, that might be a contributor also.

[DeadFish]

Another sweet looking accomplishment Willie!

It is always enlightening to hear other's reflections of a 'zen moment', when mistakes of the past become crystal clear.  And no folks, I don't always allude to 'mystic crystal revelations and the minds' true liberation' stuff, but just catching an earlier "Duh!" moment.
 
"What was I thinking?!"
(I have an AWful lot of those to catch up with!)

Yeah Scott, that might be yet another thing to tinker with the ol' hummin' bastard.  I need to get on that...  Well,  soon....one of these days....

Ayup.


 
Regards,
DeadFish

[electricbear]

In a recent training that I did with Mr Nauber of Classe he explained the benefits of hand designing circuit boards rather than allowing a computer to do it. One of the benefits was that a person would know to rotate certain components to prevent hum whereas a computer would design for the shortest signal path. I guess your rotating of the transformer was exactly what he was talking about.