Output Transformer Orientation to Toroidal Power Transformer

[Littlewyan]

Is there a correct way to mount your Output Transformer with respect to a Toroidal Power Transformer?

[Zippy]

I'd start with the headphone method of locating the transformer.

[Aurora]

Should be rather uncritical, as toroids have an extremely low stray field compared to EIs....
a listen test is still worthwhile,

[Littlewyan]

I'll try and do a listening test when I get the parts. The only part I've ordered so far is the Head Cabinet. Planning the layout before I purchase the rest of the parts.

[Littlewyan]

On an EI Transformer which sides does the magnetic field tend to stray out of? Is it the exposed sides that are sometimes covered by bell ends or the mounting sides?

[strelok]

Back when I used to work for a studio electronics company we would frequently have to tune toroidal PT's in mic pre's. We'd install the transformer without cutting the leads to length and hook the preamp up to a scope and VU meter with no signal coming in and rotate the transformer until the noise level was at its lowest. There was usually two sweet spots where the noise would be lowest usually about 180 degrees off from one another and one would generally be lower than the other. We'd mark a line with a sharpie on the transformer and pcb to save the alignment pull it out and cut the leads to length. You might try something similar as there was about a 5-10db difference in noise generally from the highest to lowest point. As far as the EI transformer goes I couldn't really say, but generally you are worried about 60 cycle noise coming off of the PT into the rest of the system and not vice versa.

[Littlewyan]

Ok I think i'll definitely do the listening test. Unfortunately there are only two places the OT can go. Next to the IEC Socket about an inch away from the PT or between the PT and a multi cap can. However between the PT and multi cap can not only will it be closer to the PT but the leads will be longer. So probably best next to the IEC Socket, just have to find out what angle is quietest. Thanks for the info.