Royer 121 style build

The 121 motor is not an especially complicated design, but everything is nicely made and the transformers are good.

You can simply offset the ribbon by placing a couple of shims under the ribbon clamps - if that's what you want to do.

I will also look into measuring frequency response, that's good to know zebra50.

Regards

Spence.

Have all the mic body put together now just gotta put together the elements.
I am going to do several different sizes, I am doing 50mm long sized neodymium magnets, ribbon thickness of 5.08mm. Also doing 40mm long magnets. Will compare the two.
I am also building a ribbon corrugator, a friend is designing several different gears which can be used to give different corrugation. Triangle shape and round tooth shape.

Regards

Spence.

ribbon thickness of 5.08mm

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Spencerleehorton said:

As per my design ideas, I feel it's right to say that I am loosely basing the style of this ribbon mic on information that I have gathered about the Royer 121, the shape of the mic externally will not look the same as the 121 as it is in a 35mm pipe rather than a 25mm, so the capsule element will all be internal but same dimensions as original hopefully, so more like the 101 style.

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The sound will be quite different from original 121, as different body dimension will have differently tuned resonator and different LF damping. But you might even prefer it over original...

I am using a Russian transformer which I have lying around which is good for ribbon mics 1:36 ratio...

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Is it Oktava toroidal transformer?

ricardo said:

One thing you WILL see on a impedance plot is unwanted resonances in the ribbon itself. 

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That problem is more prominent with shorter and/or thicker ribbon foils. With thin enough and longer ribbons the resonances will be damped by the loading air.

Best, M

I gonna use these for building the ribbon corrugator

http://www.meccanoandsteam.com/servlet/the-873/Part-25b,-Meccano-Compatible/Detail

Gonna make a feeder for the aluminium, will share once I've made it.
Coming together slowly now.

Regards

Spence.

Hi guys,

Have made 4 bodies now, 2 bodies at 28mm diameter in copper with a 2p on the bottom and one 35mm diameter and one at 38mm diameter.
The corrugator I have made but need to get the cogs lined up a little better as whenever I feed something through it has a tendency to curve.
Once everything is straight I will run a few ribbons of and tension in a few of these and see how they sound.
Then the next step is to setup the frequency generator and try and tune each ribbon.
A friend is making me four elements which are in the style of the royer but not quite the same, a bit simpler.

Will update with some photos later.

Regards

Spence.

Hi guys,

This my first version of my corrugator.

Hi guys,

Little update

Have put together a pair of very rough stubby style ribbons and they sound great, had to re ribbon one as my api312 shredded the ribbon as there was a problem with my patch bay!
Both sound excellent now, nice detail and realism. I've done a few comparisons with other ribbon mics with Sowter transformers rather than the Russian ones mentioned earlier and the Sowter transformers sound so much more smoother in the overall sound, very noticeable.
Just waiting for the elements to be made over the next few days on CNC machine then I can ribbon them up.
A top tip for anyone re ribboning is to pre stretch the ribbon before you tension, think of it like stretching in a guitar string.
Very pleased with the results now and have a kick arse pair for overheads and room mics, also sound great in blumline config.

38mm, 35mm and 28mm diameter version, pre plating not finished.

Spence, you da DIY man.

Thanks for sharing it all with us.



Henk

No problem, that's what were are all here to do.

I know that, but few go all the way, both electronically and mechanically.

Anyway, I thought a thumbs-up was appropriate. 




Henk

Making a blumlein version for friend as they sound so good, got a wonderful drum sound as overheads mixed in the a pair of my U47 versions as room mics, D112 on kick outside and beta52 inside kick along with sub kick mic.
Really does sound amazing, will see if I can post up some samples for you all to see what you think.

Regards

Spence.

Spencerleehorton said:

will see if I can post up some samples for you all to see what you think.

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Yes please!!

Hi guys,

Here is a picture of the brass elements before glueing and drilling.

Regards

Spence.

Don't know if this will work but this is a link to a sound sample, it works when I click on my iPad.

https://attachment.fbsbx.com/messaging_attachment.php?aid=56a06297cf838adc15a45733f64255b2&mid=mid.1400180235785%3A9da798678bc7b9fb53&uid=535973494&accid=535973494&ext=1400459978&hash=AQDXxlSjmIYWqamkWIX9tKl_fD1m26xegz2TMjI4tTtZww

Regards

Spence.

Hi all,

Have put together a couple of elements with the 40mm x 10mm x 4mm magnets, have had to put two shims under the magnets to allow 6mm for the ribbon, will drill holes for clamps and then make ribbon, tension and test.
For the other two elements I am going to use 50mm x 10mm x 5mm magnets, I will need to drill out the element a little to allow space for them to slot in. Will then drill clamps, make ribbon, tension and test.

Update over weekend.

Regards

Spence.

Brilliant work - I'm following this with great interest as I'm about to start building my own pair of ribbon mics - my TX's just arrived from Riga.  My ribbon motors will be perspex ( i have a big sheet of 10mm so might as well use that - and no access to metalworking machinery except hand tools and angle grinders. )

I was planning on making a jig for the angle grinder to cut the slots in the pipe.

One question - what are you using for the end caps on the pipes ( to mount the xlrs )

On my G7 I used 50mm pipe and it was a real bugger trying to locate end caps for the pipe !

cheers
Pete

hi pete C,

end caps wise im using some aluminium that is machined to fit in and can fit a slot in XLR to XLR adapter which i have cut in half, this is them held in with screws. this is on the 38mm pipe version. the 35mm radius version i will make a end cap out of copper with two tags on the side for screws and just run the mic cable out to a male XLR, sort of same with for the 28mm version but i have used a 2pence piece and soldered on two tags which i then drill and tap M3.
i would suggest the meccano cogs to make the ribbon corrugator, just make sure you line up the cogs correctly as this took a bit of time so the ribbon doesnt get a curve when corrugating.
perspex should be fine for the element.
I use angle grinder press for the slots in the pipe, you can pick them up cheap.
yes i found for many of my pipe mics that the end cap was the real issue, thats why i had the aluminium end pieces designed and made, all i change is the outside radius now for whatever the inside diameter is on the pipe.
good luck mate.

regards

Spence.