M49 / M50 dimensions

[riggler]

Hello all,

Well after finally finishing the repairs to my car, I am so proud to say that I have come a long way with the planning for my M50-like mics. I am at the point now where I am ready to build the bodies. I was wondering if someone that had access to a mic could take some internal and external measurements for me. Any takers?

If so, I'll mock-up an image with markings for where I need measurements. I'm almost certain that the M49 and M50 share the same body and headbasket, but not 100% certain.

Thanks!

EDIT:
I just want to again say "thank you" to all of the awesome people on this forum who've helped me out so much. I hope I can return some of that by documenting my build as a nice package, so that others can benefit, maybe as a new blog...

 

[zebra50]

I'm not lucky enough to have one of those, but the TLM49 is reported to be a good copy - I can measure that for you if that's good enough.

 

[riggler]

Hey that may work! I just saw a side-by-side pic on Klaus's forum and they are very very close.

This is what I need, in mm if you can:

A. Diameter of main body.
B. Height of body from bottom of "ring" down to the top of the taper.
C. Height of "ring"
D. Thickness of ring (Should come out to 1/2 the difference of the diameter of the ring from the diameter of the body.)
E. Height of the band, top to bottom, that holds the grille together.
F. Width of the band (appears to be ever so slightly larger than the diameter of the mic body).
G. Height of the bottom taper from top (mic body) to bottom (connector housing)

From a top view of the mic:

H. Width of the grille -- measuring from the edge of one "flat side" of the grille, through the center band, to the edge of the other "flat side".


Thanks!!

 

[Walrus]

We have a pair of M50's here. If you could do a picture mock-up and put the desired dimensions required on that I should be able to get access to them as soon as they are not being used!

 

[riggler]

OK here's the drawing!

Downloadable pdf: http://www.righirecording.com/DIY/M50DimensionNotes.pdf

And a big image here:

Thanks so much!! If you can't get the internals I understand!

 

[Walrus]

OK, I'll give it a go as soon as I can, but it might not be till next week.

 

[Skylar]

What about mesh?

From a few pictures that I've seen, it looks like Neumann's typical 3-layer setup.
Wire diameters and MPI look like they might be the same as the U47 to me.
The alignment is obviously different: outer layer is at a 0° bias and the innermost layer is at a 45° bias.

 

[Skylar]

May I make a suggestion?

When measuring capsule height, in my opinion, it is more important to know height from your reference point to the center of the capsule
as opposed to, for instance, ref. to bottom of sphere or ref. to bottom of capsule.
This way the overall accuracy is not dependent on an additional measurement (sphere or capsule diameter).

As an example, I would measure from the top of the headbasket ring to the center of the capsule.

This measurement tells us where the center of the capsule sits in the internal space of the headbasket.
Now, we can experiment with different capsules and sphere sizes, etc.

 

[riggler]

Aaaah! Hey man not trying to derail you from your other stuff!!! BUT that is good advice. Walrus, can you make that measurement too.

As to the mesh, I'm almost certain it's the same 3-layer setup as seen in other Nuemann's of the period.

Interesting that David Bock's AM50 does away with the original headbasket design and mesh layers...

I am going to keep to the original. Found a mesh place out of NJ that may be able to get the right goods, but Skylar, if you already got it rollin...

 

[Skylar]

I don't have anything rolling.

Just tossing in a couple pennies.

 

[zebra50]

We have a pair of M50's here.

I'll let Walrus get measurements from a real one then!

...does away with the original headbasket design and mesh layers...

There seems to be a real fashion for super-open mic grills these days. That's fine if you have a dust free studio, but in the real world, I'm not convinced. (My studio would be spotless if it weren't for the pesky musicians....)

 

[Skylar]

There seems to be a real fashion for super-open mic grills these days. That's fine if you have a dust free studio, but in the real world, I'm not convinced.

I'm with you on this one.

And let's not forget the sonic impact as well.
As Stephen Paul demonstrated, the grille configuration (especially with multiple layers) can have subtractive and additive effects on frequency response.

 

[zebra50]

And let's not forget the sonic impact as well.

Yup. I think the thinking (or at least the marketeering) is that open grill = open sound (whatever that means).

One solution to the problem of producing a neutral sounding grill is the aluminium foam on the Josephson C720, which is an excellent microphone.

 

[bernbrue]

My contribution. ATM it is checked by Mr Thiersch. When it´s back again, I can do some measurements.

http://www.twin-x.com/groupdiy/albums/userpics/Neumann_M49_005.jpg
http://www.twin-x.com/groupdiy/albums/userpics/Neumann_M49_006.jpg
http://www.twin-x.com/groupdiy/albums/userpics/Neumann_M49_007.jpg
http://www.twin-x.com/groupdiy/albums/userpics/Neumann_M49_008.jpg

some more internal pictures here:


http://www.twin-x.com/groupdiy/albums/userpics/Neumann_M49_015.jpg
http://www.twin-x.com/groupdiy/albums/userpics/Neumann_M49_016%7E0.jpg
http://www.twin-x.com/groupdiy/albums/userpics/Neumann_M49_017%7E0.jpg

and some more pictures with schematic and identified parts:

regards
Bernd

(edited because of overlarge pictures)

 

[Mike Cleaver]

Wow!!!!
Thanks for the excellent series of pictures of this classic microphone, especially the annotations identifying the various parts and the annotated schematic.
I love it when someone adds to the knowledge base.

 

[zebra50]

Great pictures. Thanks!

I was just thinking how incredibly DIY it looks inside. That's meant as a good thing!

 

[riggler]

I've posted the modified-for-5703WB schematics in another thread here a long time ago. I went through like 10 iterations of the PSU design, half-learning along the way. I gotta tell you, I might abandon what I've  because I really like Max's PSU design. Got a modded version of that going on.

If (when) these mics happen I will freak. You guys are great.

The grille-thing is very important to the sound in my opinion. IF we love the sound of the 49s and 50s... then why not do it the old-skool way? Cost.

But we can do it how we want. That three layered mesh creates complex diffraction, improves RF shielding, etc... But the slant... The slant is really breaking up modal resonances in the chamber, at least tangential, maybe not axial...

Hey Bernbue, those are some shiny grills! Awesome pics! BTW your notated pics / schematic was immensely helpful in the mic pcb layout process!!!

 

[riggler]

*friendly* bump for Walrus!

 

[Walrus]

Sorry, a certain Mr L Gallagher is recording through them at the moment. Not sure when they are going to be free.... 

 

[riggler]

I don't get who L Gallagher is, sorry! I don't know who that is!!! Hope I don't sound ignorant now... ;D