Transformer Alignment

[craftyjam]

This may seem like a stupid question, but here it is.

If I have two transformers bell-facing down, layed out as in the pic, will this accomplish the same hum reduction as having one transformer bell facing down and the other one bell facing out vertically? I know you want them to be 90 degrees out of alignment with each other, but I want to be sure before I drill my chassis.

IMG_20230123_151718818.jpg

[xtian]

To be sure, use the "headphone trick". I've detailed it many time on this forum, and it's an extremely useful tool when doing your own layout.

https://www.google.com/search?q=headpho ... garage.com

[craftyjam]

To be sure, use the "headphone trick". I've detailed it many time on this forum, and it's an extremely useful tool when doing your own layout.

https://www.google.com/search?q=headpho ... garage.com

Can I know for sure without building the amp? I'm pretty sure this alignment should offer the same hum reduction since they are still 90 degrees out of allignment.

If anyone else has done this type of layout in the past and can confirm I would greatly appreciate it.

[sluckey]

Look at this...

http://sluckeyamps.com/hammond_2/hammond2.htm

[craftyjam]

Look at this...

http://sluckeyamps.com/hammond_2/hammond2.htm

Thanks sluckey! Looks like exactly what I had in mind.

[bepone]

This may seem like a stupid question, but here it is.

If I have two transformers bell-facing down, layed out as in the pic, will this accomplish the same hum reduction as having one transformer bell facing down and the other one bell facing out vertically? I know you want them to be 90 degrees out of alignment with each other, but I want to be sure before I drill my chassis.

IMG_20230123_151718818.jpg

you didnt make anything good with that orientation..still will be the el.mag. coupling between them, change the axis for output tranformer (to vertical mounting).
if you really want to go that mounting, make distance between them as far as possible.

[sluckey]

Hammond made several successful organ amps using that transformer orientation. AO-63, AO-29, and AO-35 quickly come to mind. Dr. Z converted an AO-35 to his popular Carmen Ghia amp.

[martin manning]

Can I know for sure without building the amp? I'm pretty sure this alignment should offer the same hum reduction since they are still 90 degrees out of alignment.

Yes. Just place the transformers in the planned orientation, energize the primary of the power transformer (with other leads protected from shorting), and measure or listen to the induced voltage in the output transformer. Move the OT around so you can see/hear the effect of rotation and distance.

[xtian]

Do it. It's easy, and you will avoid unwanted hum at idle.

[TUBEDUDE]

As the old saying goes "In theory, theory and practice are the same. In practice, they are different".
The magnetic coupling theory will say be perpendicular to the other field. Done!

I made several builds using the same sets of iron. They all required different alignment for minimum hum. One required the OT to be mounted to a section of angle aluminum in the "Z" axis for minimum hum!
Always so this with all iron on the chassis. After alignment of the PT and OT, adding the choke (if used) will bend the field, requiring repositioning of the trannies.

Since this is a new build, I'd recommend punching tube sockets for best performance also.. i.e. the first stage closest to the input jack, reverb or loop returns closest to their associated jacks etc.

The component alignments of mass produced amps are more for ease of manufacture than performance.
Even building a clone, the above procedures will make a better amp than slavishly repeating the shortcuts of mass production.

[JPK64]

Can I know for sure without building the amp? I'm pretty sure this alignment should offer the same hum reduction since they are still 90 degrees out of alignment.

Yes. Just place the transformers in the planned orientation, energize the primary of the power transformer (with other leads protected from shorting), and measure or listen to the induced voltage in the output transformer. Move the OT around so you can see/hear the effect of rotation and distance.

Saved me the typing.

[ViperDoc]

Thirded. The headphone trick has worked every time I've used it.

[johnnyreece]

I prefer hooking my meter up and measuring that way. I've found my ears to be subjective, but my meter doesn't lie (usually)...

[Guy77]

I am also a big fan of the headphone trick. Use it all the time.

Guy