Orientation of Power Transformer?

[joulupukki]

Normally, in a pre-drilled chassis for a specific build you drop a power transformer into its cutout. However, I'm starting with an undrilled chassis and wonder if it matters at all which direction a drop-in power transformer is mounted? 90° different than the other option, one of them gives me more room between the PT and the turret board. This is for a Deluxe Reverb power transformer and I'm assuming either would work as long as I use the headphone test/trick to determine the best orientation of the choke, output transformer. and reverb tranformer.

 

[Peegoo]

@joulupukki

Knowing how magnetic fields work and how they can interact, I like to mount both transformers so they are 90 degrees off each other.

It does seem to cut down on noise, but that may just be my imagination.

 

[joulupukki]

@Peegoo agreed. That's how I like to do it too. What's throwing me off a bit is that the Deluxe Reverb's PT is mounted with one bell pointing to the ground and one to the sky. So how do you determine which 90°F is best? Just mount the PT and then check the others for noise and go with whatever combo has the least amount of induced noise?

 

[Peegoo]

@joulupukki That is how I would do it. You cannot be certain until you prove it for yourself.

 

[corliss1]

Doesn't matter - put the PT as far to one end as you can, and then use the headphone trick to layout the OT if you want to ensure it's going to be right.

 

[Powdog]

With the PT laying flat and the OT upright, the cores are at 90 degrees no matter which of the two scenarios you illustrated. For the record, the top one is how most DRs are oriented.

 

[telemnemonics]

Yeah a laydown transformer orientation is the same, no change to the magnetic field concerns by rotating it

 

[telemnemonics]

With the PT laying flat and the OT upright, the cores are at 90 degrees no matter which of the two scenarios you illustrated. For the record, the top one is how most DRs are oriented.

Except it is pushed to one edge so tube sockets fit next to it along the other edge.
The top pic might have room but would be better slid a bit toward one edge or the other.

 

[Powdog]

Except it is pushed to one edge so tube sockets fit next to it along the other edge.
The top pic might have room but would be better slid a bit toward one edge or the other.

Every BF/SF DR made by Fender looks like this.

 

[chas.wahl]

Yeah a laydown transformer orientation is the same, no change to the magnetic field concerns by rotating it

Seems to me that's a matter of opinion. This thread (which I started awhile back) at least touches on the possibility that orienting the short end of the PT's laminations toward the rest of the stuff (and the other transformers) is preferable. Not sayin' it's gospel, and there are practical reasons why the broad side is generally presented in the Tweeds, but . . .

 

[telemnemonics]

Every BF/SF DR made by Fender looks like this.

View attachment 1090124

Seeing the DR then yeah, centered is right.
The pics the OP posted made the larger transformer size look tighter on the possibly smaller chassis.

I recently drilled a side output jack on a guitar in a very sensible spot only to find it lines up with a typical guitar stand so the guitar has to be tilted left or right.

 

[telemnemonics]

Seems to me that's a matter of opinion. This thread (which I started awhile back) at least touches on the possibility that orienting the short end of the PT's laminations toward the rest of the stuff (and the other transformers) is preferable. Not sayin' it's gospel, and there are practical reasons why the broad side is generally presented in the Tweeds, but . . .

Interesting, anyone try moving a laydown PT around with the amp running???
Good info though.

 

[joulupukki]

Seems to me that's a matter of opinion. This thread (which I started awhile back) at least touches on the possibility that orienting the short end of the PT's laminations toward the rest of the stuff (and the other transformers) is preferable. Not sayin' it's gospel, and there are practical reasons why the broad side is generally presented in the Tweeds, but . . .

Interesting findings @chas.wahl. The main reason I'm asking is that in v2 of my AB763 build I've got a laydown power transformer (as opposed to the stand-up one I have in v1). I'm trying to move away from using a cap can and instead use some nice Nichicon radial filter caps mounted to a terminal strip. But, with the short side pointing to the inside of the amp, that takes up more space. Just trying to think it through before I start drilling holes.

 

[King Fan]

Cool thread. In the other thread @chas.wahl started, I only slowly realized the plates are 'lying down' in a laydown PT, as you guys point out here.

I like pictures, and @chas.wahl had a good one in that thread. I've extracted the payoff line from the caption.

In the "best" configuration, the power supply transformer is universally the device that is rotated as shown at the right side of the illustration. The magnetic lines of coupling are least parallel in this orientation.

 

[Lowerleftcoast]

Try it out with a headphone test first. Get it to where it is quiet, then drill.

 

[King Fan]

You mean move the OT, right? Or do you mean as to PT rotation?

 

[Powdog]

Cool thread. In the other thread @chas.wahl started, I only slowly realized the plates are 'lying down' in a laydown PT, as you guys point out here.

I like pictures, and @chas.wahl had a good one in that thread. I've extracted the payoff line from the caption.

View attachment 1090198
In the "best" configuration, the power supply transformer is universally the device that is rotated as shown at the right side of the illustration. The magnetic lines of coupling are least parallel in this orientation.

Another thing to consider: the eggheads that design and build transformers for audio applications have been doing it for a really long time. They’ve been engineered and re-engineered over and over to reduce/eliminate magnetic field and flux interaction with other components. Flux measured around a modern power transformer with a Gauss meter is almost undetectable. The windings are internally shielded with copper tape. Hammond, Baldwin, Lowery, Fender and countless others have used laydown transformers without issue for years. All the overthinking has already been done.

 

[Lowerleftcoast]

You mean move the OT, right? Or do you mean as to PT rotation?

If this question was for me, I would positioning the PT and the OT in all the various configurations to find the least noise. Ime, some transformers seem to need some distance in addition to orientation to quell hum.