Transformer Bell Orientation

Does the orientation of the bells of transformers near each other bear any special attention?

In my case, the application is a guitar amplifier chassis where, from left to right, has a power transformer, a choke, and an output transformer.  I've attached a layout (i think)

Does the orientation of the bells matter?

Thanks

Normally you would see mains and O/P transformer with the cores at 90 degrees to each other , this helps minimise unwanted coupling between the two . If you energise the mains transformer ,you will be able to see  a residual waveform appearing in the O/P transformer windings ,which typically is minimised at around 90degrees . Positioning of the choke and large metal can electrolytics between the two can also help minimise induced hum and noise.

Below is the typical layout you find in a Fender tube amp , of course transformer mounting style has a bearing  ,the Fender stuff using through chassis mounting , where Marshall generally have mains  transformers with 'bell end'  mountings 

I'm glad you answered, i was about to drill holes i didn't need.  haha.

Thanks!

I always install them with the cores at 90 degrees from each other





some good reads:

https://www.tdpri.com/threads/chassis-layout-tranformer-orientation.525666/

http://guitarkitbuilder.com/how-layout-and-build-guitar-amplifier-chassis/

This is the best forum for tube guitar amplifier builds:

https://el34world.com/Forum/index.php

and notice the little reverb transformer sitting at 45 degrees. 

why?  i know the answer.  do you?

first correct response wins a free kava party in Fiji. 

Gapped?

Hey gotta be in it to win it...That's what I tell myself when I buy a lottery ticket.... or try to sink my dinner napkin from across the room....

CJ said:

and notice the little reverb transformer sitting at 45 degrees. 

why?  i know the answer.  do you?

first correct response wins a free kava party in Fiji. 

Click to expand...

I have shared this before but back when I was designing fixed install amplifiers, the more difficult were the low power models because they were physically smaller. Despite modest power they all had the same 70V-100V (constant voltage) audio output transformers, mains power, and mic preamp transformers squeezed into one chassis only inches apart. 

JR

PS: Powered mixers with reverb springs also required serious hum management, later when digital reverbs became cost effective that eliminated a major design headache.

the reverb transformer is tilted to reduce oscillation.

bad output transformer orientation can also cause oscillation.

Fender has their OPT mounted close to the phase inverter, not the preamp tubes. Marshall has their OPT too close to the 31 preamp. they did this to balance the chassis and make it so you could flip the amp to solder it up.

the 5150 has their OPT wires too close to the preamp circuit, i had to move some wires to keep that amp from self destructing.