DIY SEP EL84-EL84 Build

Do It Yourself

marantzfan

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This one should look familiar, the schematic has been posted now in a couple of threads and @paul_b has built at least one already.


I’ve long wanted to play with a SEP EL84 and with the last two designs I’ve built from Paul (SE46, SE71A) being such a hit, I decided to follow him on this one as well.

The timeline on this goes back several weeks avtually, so I already have most of the parts here already. Just finished laying things out and marking the plate to the can start drilling, cutting, etc.

Off we go!

IMG_8986.jpeg

One note, the PT orientation was changed by 90 degrees after taking this picture for minimal noise. Also, the power supply I’m building is not the same as the schematic. Paul sent me the same PT he used in his build so I’m following his “as built” version.

IMG_9029.jpeg
 
The only bad news is that I won’t be able to do anything with this project till the weekend after Thanksgiving weekend…. :(
 
In the meantime, I can share one very useful piece of information that Paul taught me.

In order to test out whether or not the magnetic fields from your transformers are causing noise, you can do the following test:

1. Tape off each secondary lead on the PT for safety.
2. Then, connect the primary to the wall voltage. I used an IEC cable connected to the IEC jack that im using in this build. From the jack I used clip leads to attach to the PT primary. Don’t turn on the power yet.
3. Connect a multimeter to the primary of the OPT closest to the PT.
4. When you are ready to measure, turn on the power to the PT and measure the AC voltage at the OPT primary.
5. Next try rotating the OPT 90 degrees and measure AC voltage again at the OPT primary to compare.
6. Turn off the power, then try rotating the PT 90 degrees, turn the power back on and measure the AC voltage again at the OPT primary.
7. Finally, rotate the OPT 90 degrees and measure AC voltage again at the OPT primary.

Write down your measurements for each orientation of the transformers and choose the one with the lowest AC voltage reading.
 
I have 2 output styles that could be helpful. A 7watt 5k UL. 8/100. And a 12watt 5k UL 8/32/300.

If there is a built is process that wants to see that transfendar outputs do
 
Finally have something to update. Got the plate and end bells back from the powder coater. Also leaned up the PT stack and sprayed it with some Rustoleum enamel.

Things are starting to look the part now.

View attachment 91267
That transformer doesn't look like it's leaning any more, good job 🙂

Finally I get to bust someone for spelling 🤣

All jokes aside it looks great.
 
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