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

poctop · Dec 23, 2012

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://cdn.groupbuilder.com/groupdiy/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://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a040b7.bmp

Schematic: M49B https://cdn.groupbuilder.com/groupdiy/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://cdn.groupbuilder.com/groupdiy/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://cdn.groupbuilder.com/groupdiy/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://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a04129.jpeg

M49C Overall Connection and Silk Screen https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a0413b.jpeg

The Safety Manual and Considerations.https://cdn.groupbuilder.com/groupdiy/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://cdn.groupbuilder.com/groupdiy/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

Note: To Operate S2 Cardiod only Switch

micaddict · Dec 23, 2012

Never a dull moment with Dan.
Might as well tell us what's the next one on the list.

Scrappersa · Dec 23, 2012

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 · Dec 23, 2012

Hi Dan,
me and my buddy are in for two 60mm round pcbs.
regards
Bernd

lotus · Dec 23, 2012

I'm in for one pcb.Eric

bernbrue · Dec 24, 2012

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

0dbfs · Dec 24, 2012

Hi Dan, I'd like to get in on two each of the proto's for the B and C versions if possible.

Cheers,
jonathan

baadc0de · Dec 25, 2012

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 · Dec 26, 2012

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,

bernbrue · Dec 26, 2012

great, edited my post
regards
Bernd

riggler · Dec 30, 2012

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 · Dec 30, 2012

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 · Dec 30, 2012

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.

DAn,

tubestation · Dec 31, 2012

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 · Dec 31, 2012

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 ,

M49b mini driver round

M49c mini driver square

3nity · Dec 31, 2012

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

Happy hollidays.

poctop · Dec 31, 2012

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 · Dec 31, 2012

here is a preliminary BOM ,

it does not include the presume C6 600pf styro and Selectable Styro C4 and also the C1 1000pf styro I presume,
Best,

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

http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=f556c18411

Let see what happens next ;D

Dan,

poctop · Dec 31, 2012

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 · Jan 7, 2013

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

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

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