Neumann M49 Clone : D-M49c and D-M49b Tube Microphone Build Thread. (+Sample)

poctop

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D-M49c and D-M49b Build Thread .

M49 Round Body version thread here :   http://groupdiy.com/index.php?topic=60108.0
M49 mic body available here : http://www.groupdiy.com/index.php?topic=52563.0

All the info Here : http://www.groupdiy.com/index.php?topic=49675.0


The Safety Manual and Considerations.
https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0357d.pdf

IMPORTANT:
You Should always have the SHLF Jumper in position in the PSU PCB ,  this will ensure that your cable shield is tied at both end of the cable and connect to 0V
you Should Also have the 0V star grounded to your case and then from there to you IEC earth ground ,


For More Information on Grounding
https://www.dropbox.com/s/6y121dasm3iw4ba/Sound_System_Interconnection.pdf?dl=0

Best,
Dan,


BOM 
Note:
missing from the BOM Styroflex Capacitor  C1  1000pf, C6  560pf  / 630V

PSU 2469 passive
http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=532017ac2f

M49 C or B Mic Parts
http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=f556c18411

Schematic:  M49C   https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a040b7.bmp

Schematic:  M49B   https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a040c4.pdf

M49 Schematic Poctop PCBS 49b and 49c

https://www.dropbox.com/s/ym5f8tur4y0rgw8/49c-round.jpg?dl=0
https://www.dropbox.com/s/wcym8uf65ov84vi/49b-round.jpg?dl=0

Best,
Dan,

PSU Schematic : https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a040e7.pdf
Note : the Toroidal tranformer secondary is wired in parrallel to get 120V at the input of the psu

Cabling connection From PsU https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0410e.jpg

The 20Vac traffo for Europe will not fit as per the current BOM please replace it with this one or an equivalent ,
http://www.mouser.com/ProductDetail/Hammond-Manufacturing/186B20/?qs=sGAEpiMZZMvwUzoUXIIvyQPvPmwnNFGyR%2fQB%252b1BzrOY%3d
also The fuse will be 0.1A instead of 0.2 for America



M49B Overall Connection and Silk Screen https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a04129.jpeg

M49C Overall Connection and Silk Screen https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0413b.jpeg


The Safety Manual and Considerations.https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a04147


Connection For AMI T49 to PcB
TRFO to Mic PCB
A- 4
B-3
C-1
D-2

For Converting the 5840 Tube to a Triode Tie pin 7-5 Togheter Do not use Pin 4 or Pin 8

5840 Tube Datasheet https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0415d.pdf


D-M49c

install the floating pin First.  ( cut the other end of the pin on back of pcb but leave full lenght the one from Fgrid
58d1402a04176.jpg


58d1402a04188.jpg


58d1402a04194.jpg


58d1402a041a1.jpg


58d1402a041ae.jpg



Note:  To Operate S2 Cardiod only Switch
58d1402a041bb.jpg




58d1402a041c7.jpg


58d1402a041d4.jpg


58d1402a041e1.jpg


58d1402a041ee.jpg


58d1402a041fb.jpg


58d1402a04208.jpg


58d0281993a04.jpg





 

Scrappersa

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116
Hey Dan. Sounds like a great idea. I would love to be one of the people to put together one of the sample pcbs. With all of your boards, one could have the ultimate mic locker.
 

bernbrue

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Dan,
just an idea. Would it be possible to make two round versions? One with the diameter of the M49 body (60mm) and another smaller one with the diameter of the Alctron GT-2B, short U47 type body (50mm).
regards
Bernd
 

baadc0de

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Jul 8, 2009
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Location
Europe
Not sure if these are proto or debugged versions, but I'm all for one b and two c when these are debugged (if there is need for that, otherwise put me down immediately). Fitting in a 60mm round body.
 

poctop

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Messages
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bernbrue said:
Dan,
just an idea. Would it be possible to make two round versions? One with the diameter of the M49 body (60mm) and another smaller one with the diameter of the Alctron GT-2B, short U47 type body (50mm).
regards
Bernd

The 2 version above should fit the GT2B type as they are the same size as the FET pcb i am currently working on a circular version i will start with the 60mm version ,  the 2 version above will be mounted in verticaly in the gt2b style body with the tube on one side and the component on the other side ,
i am on it at the moment ,  :)

Dan,
 

riggler

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Pennsylvania, USA
Hey Dan,

I am making progress as far as getting the bodies to come in at a reasonable price! The one thing to watch out for on the 60mm round PCBs is that there are three holes for where the standoffs go up to the top cap. I will send you a drawing on what I am doing for my bodies if that would help, if you are interested in incorporating that.

Damian
 

poctop

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Messages
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riggler said:
Hey Dan,

I am making progress as far as getting the bodies to come in at a reasonable price! The one thing to watch out for on the 60mm round PCBs is that there are three holes for where the standoffs go up to the top cap. I will send you a drawing on what I am doing for my bodies if that would help, if you are interested in incorporating that.

Damian

PM sent ,
Dan,
 

poctop

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That might look like this ,  Needs some polish and the square version is redone to miniaturize again for proper railing clearance and better connection scheme


this square version should fit the GT2B body 44*48mm and the aMI t49 just on the touch, will post picture soon.
and this one sould go in your mic body. :)

Let me know the Coordinate of the mounting hole. 

rb.gif



58d0281993a17.gif


DAn,
 

tubestation

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Hello!! This  is a nice Project!! Witch Tubes are you using? 5840,5702,5703,Ec 71? Threre is no real substitute Tube for the Ac701 but I wrote in the Prosoundweb Forum that IO audio uses Ec 71 Tubes in an Ac701 circuit with good results.The Kathoderesistor needs to be aligned .Somewhere i wrote also that the EC 1000(Electrometertube) can be used as well (if you have one )how about the Tube Cj uses in his new cascade u47 mic?Did anybody design a Transistor Circuit like the Andreas Grosser Vf 14 Replacement , for the Ac 701Tube?(With a different Powersupply)A few Days ago I saw a MXL G  Trac usb Mic witch Headbascet looks very similar to a M49!!
Thank You very much!!!
 

poctop

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So these are the final Version , the square version (44mm * 48mm) should fit the gt-2b style , and the round version is 60mm diameter should fit upcoming riggler mic body 
i have been able to fit 2 mounting hole as per riggler drawing of 5.05mm mouting , i am to produce gerber at the moment so i will probably run a very small batch of those , so if any interest let me know ,  this will be an experiment for sure ,  there is 2 versions of each to accomodate the M49b and M49c version.

Stay tuned ,

M49b mini driver round  Note : the Bypass cap will go underneath the first plate as it is not show here only connection point ,
58d1402a04297.gif


M49b mini driver round
58d1402a042a3.gif


M49c mini driver square
mbs.gif


M49c mini driver square
58d0281993a27.gif
 

3nity

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you waisting no time huh!
Im running out of place to store mics Dan.

Happy hollidays.
 

poctop

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3nity said:
you waisting no time huh!
Im running out of place to store mics Dan.

Happy hollidays.

Yeah Thanks Trinity , I said to myself i'd give my maximum in 2012 and then i could get super lazy in 2013  ;D
Best,
DAn,
 

poctop

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A quote from Oliver A,

Hello Guys,

there are a bunch of tubes that will work and pass signal to call it close enough to an AC701, but there is virtually no tube that will sound the same. 
There is the AC761 made by RFT an east german copy, that looks and feels the same but the noise figures are pretty bad compared to an real one.
The EC1000 looks pretty similar and gets close to the sound, but the lifetime is pretty short and noise can be an issue.
That far I used the 5840 as general replacement, it give an in the direction feel....

Best regards,

Oliver
 

bernbrue

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Wolfenbüttel - Germany
poctop said:
Stuff for both version for 1 mic , note there is a 22K and a 2.2K as i could not be sure of the value of R7 in the C version

It´s a 2,2K. Let me know when the round 49c proto pcbs are there.

regards
Bernd
 

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