DIY FET47 mic and body self wound transformer build

Hi all,

Thought I would document my build of a few DIY FET47 mic bodies and transformers,  I've already wound the transformers and completed most of the pcb just waiting for a couple of 2.2uf tantalum to finish components.
I have figured out a way to make the body from reasonably cheap parts, it will require me to CNC some parts like the base, inner structure to hold capsule plate and pcb. Also CNC of a clear capsule mount.
I will then nickel plate and polish.

Regards

Spence.

I've drawn out a ruff sketch of the bits I'm gonna cut.

And these are all ruff measurements until all the bits arrive.
52mm copper pipe 100mm long
52mm internal diameter ring for top of head basket (copper)
52mm internal connector for bottom of head basket (copper)
2 X straight connecting pieces of copper for headbasket (copper)
53mm round bar (aluminium) lathe down to 52mm and recess and drill holes
Straight internal bars for pcb (copper)
Mount plate (copper)
Capsule mount (acrylic)
Large and small mesh

I'm going to make 4 bodies, I will then nickel plate and polish.

Spenc.

Got a spare bit of 54mm and copper rings have arrived, sizes looking good so far.

Pipe and solid arrived now, I can start on the bottom bells and cutting the bodies, just waiting for the connector to come then I can start on the headbasket.

Just had 5kg of UI-35 lams, bobbins turn up and the rest of the other bits for the bodies.
Will start cutting the base and bodies, the do the headbaskets.
Meanwhile time to start winding some BV-08, BV-12 and API input transformers!

Spence.

Did a bit today, cut the bodies and used the lathe to reduce the bottom bells.

done a bit more today.

little futher

nothings cut to size yet, just getting basic cuts then filing and sanding down, then a nice polish.

looks good. where did you get the mesh for the headbasket?

Those rings look remarkably like plumbing olives…

With all these things you're building, when do you find time to sleep??

Nick Froome

Hi,
I got the mesh off eBay, and yes I did get some 54mm olives but I'm not going to use them as they are very soft. The 54mm T connector without solder I ended up getting and I've cut the 3 connectors off and then cut the ends again, I just need to file everything down now and I'm taking the 63mm of the original and down sizing it all to 54mm.
So the finished mics should be like the original bodies but down sized from 63mm, as unfortunately I can't seem to find 63mm tube with connectors for a good price. Have met a good contact who has a transformer company who is up the road and have some UI30 lams and bobbins which I will be making some BV-08 and BV-12 for my other mics.

Just need to get some more bits to finish these, going to get some straight 54mm connectors and see how they fair as they are much cheaper than the t connector at only £4 each.
Inner mesh I need to order, this week will be finishing the base and starting to cut the headbasket to size, then braise.
Also need to order a couple of capsules and Start on the capsule mount which I might try and get cut from a mini CNC machine I have access to.
Cutting the capsule plate and side struts I will also do.

Spence.

Wow, amazing work. The mics will look awesome. After you finish them if you have parts to spare let me know, would love to build one of this mics

I'm doing this thread so hopefully if you or anyone else wanted you could get the same stuff i have got off ebay etc and make your own.
Get some 54mm copper pipe, with 54mm straight connectors, mesh, 54mm aluminium solid bar, have a go on a lathe and have some fun!

Spence.

Scaled down CAD.

Done a little more today, 3 head basket frames done, with outer mesh cut, tonight i will be finishing off the aluminium base and installing connector.

3 down.

Going to reduce the top rings down smaller so they are all the same, bases are now routed for XLR just need to make side bars, capsule plate, capsule mount and route out bases for side bars.
Then nickel plate them, give them all a polish then check all screw holes and connections, then check pcb and transformers fit nice.
Got a nice big sheet of 3mm brass for capsule plates!

Spence.