Choke Orientation

[trem]

I guess if you have an OT in close proximity to a PT, there is potential for magnetic coupling, from the lines of force generated by the PT into the OT. Arranging the transformers at 90 degrees will help to reduce this interference..... I hope I have that close to correct.
So where does a choke fit into this scenario.?
I am building a Tweed Deluxe size chassis. I will be using a PT, then a Choke, and then the OT across the bottom of the chassis, in a relatively straight line. Do I need to worry about the Lams of the Choke as they compare to the Lams of the PT or the OT.?
I looked in my copy of Merlin's Power Supply book, but I did not see anything that addressed this.
Thank You

[Bruce / Mission Amps]

I guess if you have an OT in close proximity to a PT, there is potential for magnetic coupling, from the lines of force generated by the PT into the OT. Arranging the transformers at 90 degrees will help to reduce this interference..... I hope I have that close to correct.
So where does a choke fit into this scenario.?
I am building a Tweed Deluxe size chassis. I will be using a PT, then a Choke, and then the OT across the bottom of the chassis, in a relatively straight line. Do I need to worry about the Lams of the Choke as they compare to the Lams of the PT or the OT.?
I looked in my copy of Merlin's Power Supply book, but I did not see anything that addressed this.
Thank You

Hint.... my 5E3 chrome chassis are all made with a small Deluxe Reverb sized choke option... it is on a 30 Degree angle.

[trem]

Thanks Bruce -
Space on the chassis, and existing holes, have kind of dictated about 20 degrees. So I will see how it goes.
This is a rather Narrow/Thin chassis. It is an old. Gibson Maestro.
Thanks Again

_DSC8118.jpg Photo by jimmyminstrel | Photobucket

[Chuck H]

If push comes to shove you can always mount it proper after the amp is made! Just mount it with one screw, then when the amp is running you can move the choke around to find the quietest location/orientation.

[Enzo]

How about an experiment. It is not in the signal path, so wire length and layout is not an issue. Run a couple wires from the amp chassis, and set your choke on the table top. Away from the power transformer. Now plug the guitar into some other amp, and hold the pickups near the choke and move around to detect any field. A choke has ripple current flowing through, but it is not a transformer. That tests the choke radiating any fields.

Then scope the amp output or listen, while moving the choke around near the PT. That will test the choke picking up any radiated fields.

[trem]

How about an experiment. It is not in the signal path, so wire length and layout is not an issue. Run a couple wires from the amp chassis, and set your choke on the table top. Away from the power transformer. Now plug the guitar into some other amp, and hold the pickups near the choke and move around to detect any field. A choke has ripple current flowing through, but it is not a transformer. That tests the choke radiating any fields.

Then scope the amp output or listen, while moving the choke around near the PT. That will test the choke picking up any radiated fields.

I guess I basically get what you are saying
I am not anywhere near putting power to this amp yet, but will keep this in mind.
I Should Have/I Will Post a pic of what I have going on so far.
Thank You All

[Chuck H]

I've done similar things to determine magnetic fields around cored windings of other sorts. As a means of determining their particular magnetic field properties for the purposes of designing layouts. My personal fave I developed (no doubt long after someone else, though I don't know them so Pffft!) is a cure for a problem I had with an attenuator design. One of the inductors in the active load would react with any single coil pickup within seven feet. Squealing and whistling. So I took two inductors of half the value and wired them in series, out of phase. BUT... I did stack them right on top of each other with a copper plate of greater diameter in between. The plate helped minimize mutual inductance and the two opposing EMF fields cancelled each other as they radiated outward. Curing the problem and preserving the design. Very proud of that one.

Just proof that such experiments can work. And I love to show off.

[Bruce / Mission Amps]

How about an experiment. It is not in the signal path, so wire length and layout is not an issue. Run a couple wires from the amp chassis, and set your choke on the table top. Away from the power transformer. Now plug the guitar into some other amp, and hold the pickups near the choke and move around to detect any field. A choke has ripple current flowing through, but it is not a transformer. That tests the choke radiating any fields.

Then scope the amp output or listen, while moving the choke around near the PT. That will test the choke picking up any radiated fields.

Exactly how I found the 30 degrees with my choke, PT and open frame OT... and it wasn't radiating anything it was coupling from the PT or OT... but it reduced the hum by a visible amount. So I marked the spots and had the chassis made so it could be mounted there if a guy wanted a choke in a 5E3 for some reason.

[kkregsg]

I have nothing of substance to contribute on the choke, but I have to echo Chuck H. One of the reasons I got into amp building was to make something for my twin brother to add to his ever expanding stable of amps. It's kind of like cooking a dynamite new recipe for friends, but longer lasting!

[Chuck H]

It's kind of like cooking a dynamite new recipe for friends, but longer lasting!

+1

I actually ran a commercial kitchen for a time. In an awful location. I would estimate that 50% of the drop in's became regulars. NOT BAD!!! BUT... Awful location. I only had enough customers to pay for expenses. I had to close. Preparing food for people was the most fun I ever had losing money. Making amps isn't unlike that!

[bob p]

headphone trick?

[trem]

http://music-electronics-forum.com/t32676/

For now I will just keep my fingers crossed for the positioning you see in the pics in the above link.
Thanks for all the great Advice/Tips.
best