GroupDIY

Project Specific Discussions => Microphones => Topic started by: poctop on March 23, 2013, 06:47:17 PM

Title: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 23, 2013, 06:47:17 PM
Hi All,  Just finished Building this little magic puck,   this is an build example for the M49 in the puck Style,  it is my own flavor of the tlm49 conversion I guess ,
I Might be trying to get a hold of a TLM49 or tlm 149 body to see what happens,
It might need a dedicated mic body but for now the puck is ready for offer,   and yes it rolls.....  ;)

Best ,
Dan,  :)

D-M49c and D-M49b Build Thread .

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

M49 mic body Available Here  :

http://groupdiy.com/index.php?topic=60108.msg762707#new
http://www.groupdiy.com/index.php?topic=52563.0
http://www.groupdiy.com/index.php?topic=53018.0



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

Cabling connection From PsU https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a053d6.jpg (https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a053d6.jpg)

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


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/39511/58d1402a05413.pdf


Schematic:  M49C   https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05435.bmp (https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05424.bmp)

Schematic:  M49B   https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05446.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/39511/58d1402a05456.pdf (https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05456.pdf)
Note : the Toroidal tranformer secondary is wired in parrallel to get 120V at the input of the psu

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



Capsule Connection both version and Floating Scheme B version
(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05477.jpg)

Floating Scheme connection For C version
(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0548a.jpg)

Cardiod Only Switching Point For Full Operation ( Both B and C version) Those 2 Points needs to be bridged For cardiod Only Mode remove Bridge  ( S2a and S2b)
(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0549d.jpg)



The Safety Manual and Considerations.https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a054af (https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a054af)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a054ce.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a054e0.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a054f1.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05503.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05514.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05526.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05537.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05549.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05556.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05568.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05579.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0558a.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05598.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a055a9.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a055b6.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a055c4.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a055d6.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05601.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0561a.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0562c.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0563d.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0564f.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05662.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05674.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05686.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05697.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a056a9.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a056bd.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a056cf.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a056e2.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a056f4.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a027d0.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05714.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05727.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05738.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05749.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0575c.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05769.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0577a.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0578b.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a02922.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a057af.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a057c0.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a057d3.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a057fe.jpg)


Note:  To Operate S2 Cardiod only Switch
(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0580d.jpg)



(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0581d.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a0582e.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a04208.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993bf5.jpg)




Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 23, 2013, 07:44:46 PM
With the dimension on First Picture is there anyone having a TLM style body and check if it Might fit  or chances to :-\,

Let me know ,
Best,
Dan,
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: tskguy on March 23, 2013, 11:49:47 PM
Wow that looks very cool!!!  Can't wait to see it in a mic body.

Eric
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 24, 2013, 10:22:54 AM
Wow that looks very cool!!!  Can't wait to see it in a mic body.

Eric

Thanks Eric , I Just realized that i needed to move C5 a bit to better wire the mic ,  i just updated the picture to make sure i dont make the same mistake again, 

Best,
Dan,
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: zebra50 on March 26, 2013, 02:07:14 PM
Looks great - I might have a shot.
I have a TLM49 that needs abusing! What do you need to know?

Cheers
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 26, 2013, 02:11:48 PM
Looks great - I might have a shot.
I have a TLM49 that needs abusing! What do you need to know?

Cheers

from the base to the top of capsule mount i have 105mm i wanted to see how the relationship would translate in a this body , if the capsule would sit a the proper level wihout too much shimming , hoping it would be shimming up  :),

Let me know,
Best,
Dan,
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: zebra50 on March 26, 2013, 02:17:57 PM
OK - will try to find time tomorrow and measure inside the body. I have quite a lot of work on so might get distracted.

Cheers
Stewart
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: dmp on March 26, 2013, 02:26:18 PM
Diameter is 40mm? Is that what the first pic says? Much smaller than I thought - I recall 60mm?
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 26, 2013, 02:30:45 PM
Diameter is 40mm? Is that what the first pic says? Much smaller than I thought - I recall 60mm?

the puck is 60mm dia and from the pcb base to the top of capsule mount is 105mm
Best,
Let me know,
D
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 26, 2013, 03:24:33 PM
Just had the measurement form Winetree ( Thank, )

approximatively 105mm & 104.7mm , this must be a miracle,

Best,
D
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: dmp on March 26, 2013, 03:29:10 PM
But... a tlm49 is over $1000! To use for a mic build?
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 26, 2013, 03:36:07 PM
But... a tlm49 is over $1000! To use for a mic build?

there is tons of options to explor still.  :)
 but yet still a tlm49 comes with a body and a neumann K49 or K47 not that bad  ;)


I wander if the cheaper tlm102-103 have the same body Anyone ?>

Best,
DAn,
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: HellfireStudios on March 26, 2013, 03:43:39 PM
But... a tlm49 is over $1000! To use for a mic build?

Neumann M49 is around ten thousand dollars these days. A TLM49 conversion at a fraction of the price sounds like a great deal for essentially the same mic.

Does anyone know of any similarly sized/shaped donor bodies for the D-M49 (hopefully cheaper than a Neumann)?

-James-
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 26, 2013, 03:48:44 PM
is the K49 and K47 the same thing  ?
D
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 26, 2013, 04:04:10 PM
got it ,  from Mr, Neumann.

there is no problem at all. The official name now is "K47/49", part no.
53291.

In earlier days we made a distinction, K49 was the best possibly matched
capsules front/rear; K47 was the second best classification; and for the
U47fet we needed only one side to be perfect, so that capsule was called
K47fet.

Now, our tolerances in the production of this capsule are so small that we
do not make this distinction anymore, and both K47 and K49 are now called
K47/49, and are used for all U47, U48, M49, M249, M149Tube.
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: micaddict on March 26, 2013, 05:32:38 PM
Quote
I wander if the cheaper tlm102-103 have the same body Anyone ?>

TLM 103 is smaller, with the headbasket of the U67/87.
TLM 102 is smaller still.
And neither has a K47.
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 26, 2013, 05:41:47 PM
Quote
I wander if the cheaper tlm102-103 have the same body Anyone ?>

TLM 103 is smaller, with the headbasket of the U67/87.
TLM 102 is smaller still.
And neither has a K47.

Thanks Henk,
Best,
Dan
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: gary o on March 28, 2013, 07:56:06 AM
Hi I been watching these build threads trying to learn about great mic circuits as experiments I have knocked up some M49ish circuits using 5940 tubes & Olivers TLM149 conversion schematic... was also thinking buying a TLM149 for body & real capsule

Poctop you say this is your flavour of this mic so are you using the schematic posted at beginning I have only just noticed the neuman schemtic seems to have some sort of feedback built in, I havent made that part of the circuit for my experiments  YET

https://www.google.co.uk/search?q=samson+usb+mic&hl=en&source=lnms&tbm=isch&sa=X&ei=MC9UUa-dAoHU0QXSpYHICw&sqi=2&ved=0CAcQ_AUoAQ&biw=1920&bih=955#hl=en&tbm=isch&sa=1&q=samson+g+track+mic&oq=samson+g+track+mic&gs_l=img.12..0j0i24l4.5634.9968.0.12686.12.12.0.0.0.0.103.973.11j1.12.0...0.0...1c.1.7.img.wSqdXi6Bu8c&bav=on.2,or.r_cp.r_qf.&bvm=bv.44442042,d.d2k&fp=43934509a21db43&biw=1920&bih=955&imgrc=b2TUAxZ6ucIV3M%3A%3BybJju97crrLbZM%3Bhttp%253A%252F%252Fwww.maclife.com%252Ffiles%252Fu36%252F0911_samson_gtrack_380_2.jpg%3Bhttp%253A%252F%252Fwww.maclife.com%252Farticle%252Freviews%252Fsamson_gtrack%3B380%3B585

Anygood for a cheap body
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: micaddict on March 28, 2013, 08:45:53 AM
I'll let Dany chime in about the schematic, but regarding the Samson body, that one only has a 54.2 mm diameter. On the outside that is. The round D-49 PCB is 60 mm.

The good news is that the D-49 also comes in a square version. This will fit nicely in the Alctron GT-2B body or Thomann's SCT-700.

http://www.vintagemicrophonepcbkit.com/DM49.html (http://www.vintagemicrophonepcbkit.com/DM49.html)

The guy thought of everything.

Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: gary o on March 28, 2013, 09:16:35 AM
Thanks micadict thats a shame Samson a little too small thought would look nice ..... I could prob squeeze my point to point version in that body tho so might grab one they cheap enough

Thanks
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on March 28, 2013, 09:31:06 AM
Hi I been watching these build threads trying to learn about great mic circuits as experiments I have knocked up some M49ish circuits using 5940 tubes & Olivers TLM149 conversion schematic... was also thinking buying a TLM149 for body & real capsule

Poctop you say this is your flavour of this mic so are you using the schematic posted at beginning I have only just noticed the neuman schemtic seems to have some sort of feedback built in, I havent made that part of the circuit for my experiments  YET


Anygood for a cheap body

I guess it is my flavor of the mouting and layout , but those are  the 49b or 49c as the per the orignal schematic ,  feedback included :),
BEst,
DAn,
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: gary o on March 28, 2013, 12:16:09 PM
I see what you mean Dan great stuff thanks, Im going to try adding a little feedback to my experiment

All the bast cheers
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on April 08, 2013, 04:00:49 PM
Here is some  alternatives for the 5*11mm caps needed specifically for the M49bc square and round,  also in the U67 and 269c mic,


http://www.alliedelec.com/search/searchresults.aspx?dsNav=Ntk:Primary|MKT1813310405|3|,Ny:True,Ro:0&dsDimensionSearch=D:MKT1813310405,Dxm:All,Dxp:3&SearchType=0 (http://www.alliedelec.com/search/searchresults.aspx?dsNav=Ntk:Primary|MKT1813310405|3|,Ny:True,Ro:0&dsDimensionSearch=D:MKT1813310405,Dxm:All,Dxp:3&SearchType=0)


http://canada.newark.com/vishay-roederstein/mkt1813310405g/capacitor-film-0-01uf-400v-axial/dp/26M1636?Ntt=MKT1813310405

http://canada.newark.com/vishay-roederstein/mkt1813-310404/capacitor-poly-film-0-01uf-400v/dp/18M2494?Ntt=MKT1813310404

http://fr.farnell.com/vishay-roederstein/mkt1813310405g/condensateur-0-01uf-400v/dp/1166851?Ntt=MKT1813310405

Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on April 08, 2013, 05:20:49 PM
The P.S. BOM shows Rotary Switches SP3T SHRTNG 1.5" ACT
for the pattern select switch only allowing 3 choices.
Can another pot  be used for variable pattern select like the orginal M49? What value?


https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993d09.pdf (https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993d09.pdf)

you absolutely can,   if you look at the schematic attached,  all you have to do  is :

use a 100K lin pot ,

and connect the wiper of the pot to the COM pad ,   one side of the pot to OM and the other side of the pot to F8 pad,  this way the pot will act as a voltage divider from 0V omni  to 120V figure 8 ,


I did that this way to avoid having to solder resistor on the 3 pole switch   I used a 3 pol switch cause i am not a very big user of the infinite pattern possiblity
of the mic ,  i am just using fig 8 , omni and cardiod ,  but this will not prevent you of doing this that way , that is why i like DIY , you can make it the way you like , but in this case it is very easy to modify,

Best,
Dan,
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on April 13, 2013, 03:53:31 PM
For those that will be building the mic project that needs the 0.01uf  capacitor in the package 5*11mm  i have been able to change mouser minds to offer a 10% variation at a minimum qty of 1  ;),

here is a link for it ,
http://ca.mouser.com/ProductDetail/Vishay-Roederstein/MKT1813310405/?qs=N5kmjX/bzE4Fjs7uA0EePA==

i aslo went over my BOM and added in the customer part number cell some nice subsitution for the parts that went back order , should be all good now ,

Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on April 26, 2013, 09:14:10 AM

All M49 models after 1957 had a “cardioid only” switch built in, to achieve a 4dB s/n improvement [as compared to setting the pattern] remotely, from the power supply.


Note:  To Operate S2 Cardiod only Switch
(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993d39.jpg)

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on May 17, 2013, 09:54:04 AM
Hope checking those picture will help finding your issue , this is what i have here , works like a charm  :)

What is the ratio of your transformer ?  .....  Where do you actually Measure the Kathode voltage against what reference ?

B+ was readjusted to 120V afterwards hence the 50V  on the plate wich is about 4-5V higher than the cal point at (116V-120) = 50-4= 46Vplate.

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05b1d.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05b2f.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05b40.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05b51.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05b62.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a05b72.jpg)

(https://dl.dropboxusercontent.com/u/43869772/D-M49BC/M49C%20Measurement/7_7.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993d75.jpg)

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on May 17, 2013, 11:00:17 AM
Hi guys,

With the PSU set to 116v i get the following:

K = 0.9v
A = 38.3v
H+ = 5.9v

any ideas?

regards

Spence.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on May 18, 2013, 06:18:44 AM
Hi,

Is there a way of going back through the voltages in my build until i find where its going wrong?

also this is my tube, could this be a problem?

http://www.ebay.co.uk/itm/380399247271?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

really want to sort this as im also building a M49 body and want this mic to work flawlessly in this.

regards

Spence.

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on May 21, 2013, 04:37:30 AM
Hi All,

found my problem, leaky C9 cap, top tip always check the caps!!!
headache over now!!! onto building some!!!!

regards

Spence.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on May 23, 2013, 04:02:55 PM
Way To go Spence,   8)

Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on May 28, 2013, 07:11:43 PM
thanks to micaddict this is an intersting about how the M49 is one of the most overlooked Mic in the neumann History and Many nice info and comments about those and the M149 wich is the modern Version.  it does also contain a Shameless Plug of mine.

http://www.gearslutz.com/board/high-end/840056-neumann-m49-vs-m149.html

Best,  :)

Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: tonycamp on June 13, 2013, 12:42:55 AM
Hi Dan, thanx for the 47fet stuff, getting going on it soon.
I'm also fired up for this M49 project, i want to get Erics new body thats coming out, but i just found out the AC701K is $500 large!!! Is there a substitution tube? I could handle the $500, but i hear through Christian Whitmore that they're not easy to test, a lot of fake, and a crapshoot at best. What do you recommend?

excuse me if this is covered somewhere, i looked and found nothing

thanx
Tony
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: micaddict on June 13, 2013, 03:56:45 AM
Quote
Is there a substitution tube?

Yes and no. There's no close copy. But the 5840/EF732 is a very nice substitute, in any case for the -b configuration (fixed bias). Many use it and the M49 clone in this here thread has it, too.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: bruno2000 on June 13, 2013, 09:48:56 AM
The first U64s used the AC701 tubes, but the latter ones used a 7586 Nuvistor.  Has anybody played with the 7586 for this build?
Best,
Bruno2000
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: tonycamp on June 14, 2013, 10:07:48 PM
thanx addict, good stuff
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: tskguy on June 20, 2013, 08:50:03 PM
Hi all,

Quick build update..
Everything is finished on the mic except for the capsule! Power supply needsto be finished and tested, i hope to have it finished by Saturday.
The spacers I ended up using are half inch on the very bottom 1 inch between the TX PCB and the circuit PCB and another half inch spacer at the top to hold the capsule board. From what I can judge this seems to be setting the capsule heighth about right.

(http://i280.photobucket.com/albums/kk187/tskguy/2013-06-20072728.jpg) (http://s280.photobucket.com/user/tskguy/media/2013-06-20072728.jpg.html)
(http://i280.photobucket.com/albums/kk187/tskguy/2013-06-20072614.jpg) (http://s280.photobucket.com/user/tskguy/media/2013-06-20072614.jpg.html)
(http://i280.photobucket.com/albums/kk187/tskguy/2013-06-20072647.jpg) (http://s280.photobucket.com/user/tskguy/media/2013-06-20072647.jpg.html)
(http://i280.photobucket.com/albums/kk187/tskguy/2013-06-20072959.jpg) (http://s280.photobucket.com/user/tskguy/media/2013-06-20072959.jpg.html)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: wave on June 20, 2013, 11:58:37 PM
Lookin good Eric! Now finish making your HK-47 and stick it in there so I can come over and steal your mic! BTW, did you see that I put both stepper bits in that box today?

-Dave
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: tskguy on June 21, 2013, 08:16:00 AM
Ha, you can steal my mic anytime bro!

And yes I saw the bits thanks again,

Eric
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: tskguy on June 25, 2013, 10:00:18 AM
Hey boys the mic is completed,


http://www.groupdiy.com/index.php?topic=52563.60
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on July 05, 2013, 05:39:57 PM
Hi Guys,

this may have been covered but need clarification, the schematic for the M49b version says 300k for R7, i have been told by dany that i should use a 2M trimmer?
with the 2M in i get 6.1v on the cathode and i cant seem to lower it with the timmer?
need to clean it all up and check for errors and will try a 300k resistor in there.
for the 150M resistors ive had to use 160M but thought this wouldnt make much difference?

regards

Spence.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on July 05, 2013, 05:55:46 PM
Hi Guys,

this may have been covered but need clarification, the schematic for the M49b version says 300k for R7, i have been told by dany that i should use a 2M trimmer?
with the 2M in i get 6.1v on the cathode and i cant seem to lower it with the timmer?
need to clean it all up and check for errors and will try a 300k resistor in there.
for the 150M resistors ive had to use 160M but thought this wouldnt make much difference?

regards

Spence.

Waht is your plate Voltage ,  with the B version it is not very obvious to measure the Bias Voltage direclty as there are High M resistor up to the grid from this point on,

if your plate voltage reads between 47-50V for 120VB+ you are probably fine ,  Trimming with the 2M should affect the plate voltage.
one can use the substraction method to have a ball park number for the grid bias.  what you read is the filament voltage unchanged at this node
 
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on July 06, 2013, 05:05:22 AM
sorted the issue on one, was my fault wiring in the transformer!!, the M49c one still buzzes a little so will look at next week!!!

regards

Spence.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on July 22, 2013, 08:14:10 PM
Kit in stock,

http://www.groupdiy.com/index.php?topic=49675.480

Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: bruce0 on July 25, 2013, 11:40:52 AM
Looking for sources for capsules as I pull together the BOM and I could not find a consolidated list.  I pulled this together, but am I missing some names?  Not sure if the MFG/Distributor labels are correct. I have just listed "names" rather than links because the links go bad fast (just look at the meta).

MFG
Dale
Campbell Transmitter
Peluso
Beezneez
Tskguy
Theirsch

Distributors
Alctron (and other China based sources)
Microphoneparts
Canadian Audio Distributors

Other
Andreas Grosser?

Original commercial

Neumann
Sennheiser
Etc
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: HellfireStudios on July 25, 2013, 12:42:24 PM
Thiersch and Sennheiser/Neumann sell capsules too.

-James-
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: tskguy on July 25, 2013, 03:46:32 PM
Hey all,

Here is a clip of my M49b proto that Wave and I did. They are of some ACG and Vocal. They line up if you want to add to a session. This is also a bit of a shameless plug mainly because the mic also has my k47 style capsule in it.

For some reason I was getting a little noise from the tube (I think) ??? so please forgive that.

Now don’t just listen and not say anything.. I want honest opinions!!! Everyone has been so quit when anyone posts clips.

The recording chain was 9098 pre amp in to pro tools at 16bit 44.1


https://www.dropbox.com/s/hfnvasqfz17rrby/M49%20ACG.wav
https://www.dropbox.com/s/mkkbsoi6odzs9in/M49%20Vox.wav
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on August 11, 2013, 11:37:13 AM
important Information For All M49 and 269c builder

the psu pinout  connection shows that pin 3 is the cable shield lift channel with the jumper that should be by default installed on the psu , unless a specific cableshield scheme is used  and that pin 7 is the Audio Ground ,

on the M49 Mic pcb as per the original numbering the pin 7 is actually the shield from chassis and the pin 3 is the audio ground ,
since the 2 points are linked on the pcb they are basically the same but special attention must be taken to actually take into account for this properly grounding the mic and cableshield as the number are reversed on the mic end ,

take special attention to ground loop while grounding the shield of the mic cable ,


Side Note: For those having a polarity that is reversed for a known or unknow reason , remember that you can swap the wire inside the psu at the xlr output connector swapping wire pin 2 and wire pin 3 will reverse the polarity of the ouput.



the same PSU can be used for the M269C build but note that the difference is that pin 3 is the calibration input on the mic pcb not the shield ,
there is a pad on the 269 pcb labeled Cal on the mic pcb. Always have the original schematic of the mic when building as all the numbering on the mic pcb always follow the original numbering on the schematic as opposed to the psu that will always stay te same for both mics 49bc-269c ,
the remote pattern on the M269c is like the original as well that is you have to switch on the mic pattern and then on the psu to get the poper pattern , ( see schematic)  the use of a linear pot can be used in both configuration for the pattern ,

Best,
Dan,
 
I went to update the PsU schematic with proper labeling of the output pin of the psu and also did this little table that will help explain


Cabling connection From PsU https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993e53.jpg (https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993e53.jpg)

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on August 18, 2013, 06:22:03 PM
this is a bit confusing, ive read this several times and im still not exactly clear what you mean?

do you mean:

M49 b + c version:

the psu pcb is wired to the 7 pin connector normally 1-8?
on the 7 pin connector on the mic you do the following:
pin 3 goes to 7 on the mic pcb
pin 7 goes to 3 on the mic pcb

pin 8 on the psu goes to chassis

is this what you ment?

regards

Spence.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: poctop on August 18, 2013, 06:59:58 PM
this is a bit confusing, ive read this several times and im still not exactly clear what you mean?

do you mean:

M49 b + c version:

the psu pcb is wired to the 7 pin connector normally 1-8?

pin 8 do not connect from psu it is a calibration input on the mic only

on the 7 pin connector on the mic you do the following:

pin 3 goes to 7 on the mic pcb
yes
pin 7 goes to 3 on the mic pcb
yes

pin 8 on the psu goes to chassis
no pin 8 do not connect on psu it is just on the mic and it is a calibration input at the mic only

is this what you ment?

regards

Spence.

yes it is the same for Both M49b and c,

basically the pin 3 from the psu will connect to (pad 7 (Chassis) on original schemo) at the mic pcb  and the pin 7 from the psu will connect at pad 3 at the mic  ( Circuit ground from original schematic) 

if you look at the schematic , pad 3 and pad 7 are both ground so it does not realy mattter , but if you have a ground loop or issue you will be able to tell that the chassis and shield return is tied to psu with a jumper for a gnd lift but not the circuit ground wich must not have a jumper ,

So they are the same level on the pcb but on the psu only pin 3 has a ground lift for the shield or chassis.
it is just to avoid confusion to actually wired the circuit ground to a jumperable connection

hope this helps ,
Best,
Dan,


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on August 19, 2013, 07:14:15 AM
HI Dany,

Ok i think i get it all now:

on mic connector in mic, swap pins 7 and 3
on psu dont use pin 8 on pcb

Onto the other issue of noisey psu for these, i have changed over the cheap 20v transformer for the same one in the good psu which doesnt have any noise and there still seems to be a little noise.
I was wondering whether the caps in the psu could be the culprits as ive used another cheaper type in the two that are noisy and in the quiet one i have the white versions as specified in the BOM, i do have more of these so could change one psu to see if there is any improvement? but would it be these?

regards

Spence.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: Spencerleehorton on August 19, 2013, 08:00:36 AM
Hi Dany/everyone,

have changed the 0.1uf 400v caps to the white ones from mouser in the BOM and buzz gone, PSU now sounds pretty much exactly the same as the good one now, slight difference but minimal, btw i am testing this as very high gains and have recorded all the noise floors to compare in protools.
I also used some wire that i wasnt completely happy with which i have changed for brand new good quality stuff, a must for everyone dont scrimp on anything or you'll get noise stuff!!!

much happier now!!! :)

regards

Spence.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on September 05, 2013, 06:24:56 AM
Sorry if i missed it somewhere, but what transformer options are there on this M49 puck style build?

All pics of builds shows the AMI T49... what about Kirchers BV.11?

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 05, 2013, 07:38:43 AM
Sorry if i missed it somewhere, but what transformer options are there on this M49 puck style build?

All pics of builds shows the AMI T49... what about Kirchers BV.11?

The Current Kit Supports the amazing work of Max BV11,  the AMIT49 and any other transformer that will fit the bill

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993eb6.jpg)



Best,
DAn,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: gary o on September 20, 2013, 08:33:54 AM
Re OP transformers what are soud differences between Max BV11 & AMIT49 ..........also should any 10:1 transformer work, I currently use a Hauf original T14/1 .... sounds good but wondering about the sound differences as I may usr my T14 for a C12

thanks chaps
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on September 28, 2013, 02:02:46 AM
OK I just joined this club! Dan I sent you $$ for a round board set!! Can't wait to get this going!

Any word on the Latch Lake mounts? Sounded really really good!

Excited!

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on September 28, 2013, 05:25:33 AM
Just bought a few 5840 JANs off ebay:

http://www.ebay.com/itm/5-NOS-Raytheon-JAN-5840W-Subminiture-Audio-Radio-Microphone-Vacuum-Tubes-NIB-/290897652222?pt=Vintage_Electronics_R2&hash=item43bad9e9fe (http://www.ebay.com/itm/5-NOS-Raytheon-JAN-5840W-Subminiture-Audio-Radio-Microphone-Vacuum-Tubes-NIB-/290897652222?pt=Vintage_Electronics_R2&hash=item43bad9e9fe)

I was a little concerned these are the JAN versions - in one thread I read that the JAN's were Joint Army Navy stock and could be very harsh unless specifically made for audio. But it seems like folks are using these here and Poctop's samples sounded smooth and great so...dunno. I usually try to get premium parts so mebbe I'm slipping heheh...

Anyway, anyone have any thoughts on the JAN versions?

Thanks,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on September 28, 2013, 07:03:17 AM
What transformer are you planning to use Phrazemaster?

I'm also giving this project a try and just ordered the AMI BV11R to use with a 5840 tube.

Haven't decided on what 5840 tube to use yet.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on September 28, 2013, 02:44:17 PM
Hi Edward, I'm going with Max (ioaudio)'s BV11. I realize it may not be mated for a 5840 as well from what I've read, but I think the guy does a bang-up job on his stuff and I'd like to support him. I bought a BV12 from him, and although I still have to test it, looks amazing!

Plus, the 11r is a lot more than I want to spend right now; Max's Bv11 is sitting pretty right in the middle.

I pulled the trigger and bought some JAN 5840's; reading suggests they could be harsh for audio use, however, I noticed that Dany (poctop) is using them and in his build his mic sounded velvety smooth so...I'm going to try the "generic" route and just ordered 5 NOS JAN 5840's for only 25 bucks. I'm usually the guy that gets super premium everything so...must be slipping lol! Or maybe the spirit of DIY and experimentation is getting to me. :)

Edward are you going to build the b or c version of the M49? I'm on the fence; not sure. Haven't found enough info on the differences to decide yet. Anyone have any info on sonic diff's betw the two builds?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on September 28, 2013, 04:51:26 PM
I first was thinking about ioaudios BV11 as well, but the audiophile in me forced me to get the BV11R...

I think I'll learn from you and get a bunch of fairly inexpensive tubes and see if I get this thing working. Then "upgrade" later if needed.

I thought I would build the b version but I'm unsure of the differences sound wise. Would like to read comments on that as well.

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on September 28, 2013, 05:24:36 PM
I hear you...and actually the 11r is cheaper, at least for me in the states due to Euro conversion.

The sample I heard of Poctop's M49 had a lot of rich full bass, and I believe he just had a T49 in there. So I just decided to go with Max's BV11 and be done with it. I just paid him for it...

Hope your build goes well! Now I'm waiting on riggler's bodies to go into 3rd round of production. :)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on September 29, 2013, 07:08:50 AM
Yes, poctop's M49b with Peluso capsule (later killed in an accident) and AMI T49 tranny, sounded absolutely gorgeous.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 29, 2013, 09:50:02 AM
Yes, poctop's M49b with Peluso capsule (later killed in an accident) and AMI T49 tranny, sounded absolutely gorgeous.

Hey Henk you remember that  ;D :),

Best,
D
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on September 29, 2013, 11:15:20 AM
You bet.
And I will never forget.  :P
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on September 30, 2013, 10:40:29 PM
Hi Dan, I found some nice Shinkoh's but they are .5W, not the 1W you listed in the BOM for the PSU. I don't have a schematic to check to see if I could use a .5W instead - so could I? I don't want to use too low a value...

Also, is this build a "faithful" reproduction of the M49 circuit, or a variation of your own? Not sure if you have already answered this question sorry.

Thx!

Mike
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: Phrazemaster on October 01, 2013, 02:32:12 AM
The P.S. BOM shows Rotary Switches SP3T SHRTNG 1.5" ACT
for the pattern select switch only allowing 3 choices.
Can another pot  be used for variable pattern select like the orginal M49? What value?


https://dl.dropbox.com/u/43869772/NUDPW2469P2.pdf (https://dl.dropbox.com/u/43869772/NUDPW2469P2.pdf)

you absolutely can,   if you look at the schematic attached,  all you have to do  is :

use a 100K lin pot ,

and connect the wiper of the pot to the COM pad ,   one side of the pot to OM and the other side of the pot to F8 pad,  this way the pot will act as a voltage divider from 0V omni  to 120V figure 8 ,


I did that this way to avoid having to solder resistor on the 3 pole switch   I used a 3 pol switch cause i am not a very big user of the infinite pattern possiblity
of the mic ,  i am just using fig 8 , omni and cardiod ,  but this will not prevent you of doing this that way , that is why i like DIY , you can make it the way you like , but in this case it is very easy to modify,

Best,
Dan,

Dan what about this pot: http://www.digikey.com/product-detail/en/RV4NAYSD104A/RV4N104C-ND/222811 (http://www.digikey.com/product-detail/en/RV4NAYSD104A/RV4N104C-ND/222811)

Is 2W overkill? How low can go? Looks like a nice pot...

And I can still add internal switch S2 across the jumpers even if I use the pot, right? That way can use the pattern on the PSU or the switch on the mic to make it cardioid only?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2013, 07:49:41 AM
Hi Dan, I found some nice Shinkoh's but they are .5W, not the 1W you listed in the BOM for the PSU. I don't have a schematic to check to see if I could use a .5W instead - so could I? I don't want to use too low a value...

Also, is this build a "faithful" reproduction of the M49 circuit, or a variation of your own? Not sure if you have already answered this question sorry.

Thx!

Mike

you should stick to 1W as this is calculated to make sure the resistor wont heat too much and will stay in the safe zone , I always calculate a little over spec to make sure the psu run as cool as it can,

Yes the Circuit is a faithfull recreaction of the M49b and c version.

Best,
dan,
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: poctop on October 01, 2013, 07:56:11 AM
The P.S. BOM shows Rotary Switches SP3T SHRTNG 1.5" ACT
for the pattern select switch only allowing 3 choices.
Can another pot  be used for variable pattern select like the orginal M49? What value?


https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993f04.pdf (https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993f04.pdf)

you absolutely can,   if you look at the schematic attached,  all you have to do  is :

use a 100K lin pot ,

and connect the wiper of the pot to the COM pad ,   one side of the pot to OM and the other side of the pot to F8 pad,  this way the pot will act as a voltage divider from 0V omni  to 120V figure 8 ,


I did that this way to avoid having to solder resistor on the 3 pole switch   I used a 3 pol switch cause i am not a very big user of the infinite pattern possiblity
of the mic ,  i am just using fig 8 , omni and cardiod ,  but this will not prevent you of doing this that way , that is why i like DIY , you can make it the way you like , but in this case it is very easy to modify,

Best,
Dan,

Dan what about this pot: http://www.digikey.com/product-detail/en/RV4NAYSD104A/RV4N104C-ND/222811 (http://www.digikey.com/product-detail/en/RV4NAYSD104A/RV4N104C-ND/222811)

Is 2W overkill? How low can go? Looks like a nice pot...  not really ,
 
usually those big pot a 1W or more , there only a tiny current going trough those so 1W will also be fine ,

And I can still add internal switch S2 across the jumpers even if I use the pot, right?
Yes you can

 That way can use the pattern on the PSU or the switch on the mic to make it cardioid only?

The Cardiod only switch applies to the same principle as the U47 as it disconnect the rear diaphragme lowering the noise,
this will be an extra switch but does not relate to the pattern switch those are separate things even tough they a related, the cardiod only switch is best to be mounted on the mic as a last resort on the psu,  it could also be activated from a relay from the psu if you wish check the AMI DIY U47 thread they speak about this.

Best,
dan,


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 01, 2013, 10:22:35 AM
Totally awesome Dan! I'll check it out~! Thanks a ton for the great info and support!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on October 01, 2013, 01:15:26 PM
I found a Mullard 5840 tube, specifications here: http://www.tubecollector.org/cv465.htm

Will it work and is it worth trying in a M49?


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 01, 2013, 02:55:46 PM
Hi Dan, I found some nice Shinkoh's but they are .5W, not the 1W you listed in the BOM for the PSU. I don't have a schematic to check to see if I could use a .5W instead - so could I? I don't want to use too low a value...

Also, is this build a "faithful" reproduction of the M49 circuit, or a variation of your own? Not sure if you have already answered this question sorry.

Thx!

Mike

you should stick to 1W as this is calculated to make sure the resistor wont heat too much and will stay in the safe zone , I always calculate a little over spec to make sure the psu run as cool as it can,

Yes the Circuit is a faithfull recreaction of the M49b and c version.

Best,
dan,

Thank-you Dan, will-do. I had read the schematic for the mic itself which has only .25 and .5w resistors, and got them mixed up...By the way do you have a schemo for the PSU for this build?

Awesome stuff as usual.

I just tried seeing about getting a FleA M49 body, as they have a kit on their website, but Ivan at FleA informed me they are no longer selling the FleA kit. So I'm waiting on riggler...:)

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2013, 03:18:16 PM
I found a Mullard 5840 tube, specifications here: http://www.tubecollector.org/cv465.htm

Will it work and is it worth trying in a M49?

if it is a 5840 no problem ,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 02, 2013, 01:55:14 AM
After a little more research, I decided on getting a honeywell conductive plastic pot for the pattern switch:

http://www.mouser.com/Search/ProductDetail.aspx?R=380C1100Kvirtualkey67810000virtualkey785-380C1100K (http://www.mouser.com/Search/ProductDetail.aspx?R=380C1100Kvirtualkey67810000virtualkey785-380C1100K)

Reasoning? Apparently carbon can be noisy, and cermet can wear out...conductive plastic is supposedly the sweet spot with best stability, accuracy, and pot rotation "feel." Oh boy!

Uh...yeah...I really do research each dot and tittle...'till I get another gf that is lol!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 02, 2013, 02:35:47 PM
I'm working with a cool guy for tubes for this build. Here is some info he shared about the different types of tubes:

The Raytheon grey plate 5840W tubes are going to be nice and warm. The black plate versions will offer greater detail. The GE tubes are a really stout construction and may offer less microphony, however these tubes should not be very microphonic. Sylvania are a nice constuction and are black plate as well.

The RCA tubes are a more sought after tube, but appear to be very similar to the GE version. I also have a high end version of the Air Force 5840A tube from 1957. This is not labelled Jan, but worth mentioning. I only have a few left, they were very popular a few years ago when I had more of them.


He was a super nice guy and cool to deal with; anyone looking for some tubes might hit up http://westubes.com/store2/ (http://westubes.com/store2/)



Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on October 02, 2013, 02:50:36 PM
Funny you should mention the RCA tubes Phrazemaster... I found these tubes yesterday, bought one set of them to try out...

http://www.ebay.com/itm/5x-RCA-CV-3929-EF732-EF-732-Subminiatur-Rohre-NOS-/321105571871?pt=DE_TV_Video_Audio_Elektronenröhren_Valves&hash=item4ac362301f

Black plate version.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 02, 2013, 03:29:10 PM
Those look good Edward!

I've spent my wad on tubes or I'd maybe snap some of those up too...sigh...DIY is a disease. Glad I got infected.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: riggler on October 03, 2013, 12:01:23 AM
I think it's important to mention here - talking about noise, etc - the importance of cleanliness around the high impedance areas in the circuit. Dirt, solder flux, fingerprints all are bad! Keeping the grid lead routed away from everything else is the most important thing I have read.

I have read that the AC701 tubes were photo-sensitive to camera flashes, so they got painted black. Has anyone read this about other subminis like 5840? I have a bunch of 5840 and 5703 tubes.

I have also seen many pictures of AC701k tubes in mics with all the extra leads not clipped off, coiled up instead. Some have said it was for heat sinking...

Phrazemaster I am pretty sure another run is happening!

And Dany, these PCBs are fabulous!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 03, 2013, 12:10:01 AM
riggler you just made me very happy! (Especially considering I just popped for a bunch of parts for this thang!). I would "Like" this post twice if I could!

Thanks for your incredible hard work!!

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 03, 2013, 03:58:24 PM
Question - the Bv11 xformers - will they lack bass extension/low end with a 5840 tube? I'm a little bummed I already ordered a max bv11 but a post said that Oliver has an AMI xformer BV11R that is supposed to be better suited for a 5840 tube...

So I'm wondering if a historic BV11 will be a problem or cause an anemic microphone bass-wise?

Thanks all,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 03, 2013, 04:14:10 PM
Question - the Bv11 xformers - will they lack bass extension/low end with a 5840 tube? I'm a little bummed I already ordered a max bv11 but a post said that Oliver has an AMI xformer BV11R that is supposed to be better suited for a 5840 tube...

So I'm wondering if a historic BV11 will be a problem or cause an anemic microphone bass-wise?

Thanks all,

Mike

IIRC 0dbfs had a little tweak on one of the cap tie to the kathod on this one , I beleive having a 10 uf instead of a 22uf as the original will thump this one up .
but correct me if i am wrong,  that would be C9 on the C version of the M49.


Best,
DAn,


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on October 03, 2013, 04:44:03 PM
Question - the Bv11 xformers - will they lack bass extension/low end with a 5840 tube? I'm a little bummed I already ordered a max bv11 but a post said that Oliver has an AMI xformer BV11R that is supposed to be better suited for a 5840 tube...

So I'm wondering if a historic BV11 will be a problem or cause an anemic microphone bass-wise?

Thanks all,

Mike

I wouldn't worry about it, Mike. Dany's own prototype with 5840 was as far from anemic as you could imagine, "even" with the T49 tranny.
I would go for M49b rather than M49c, though.

Henk
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 03, 2013, 05:18:57 PM
Henk and Dan, much appreciated!

I was trolling the 'net to find more info on b vs c, and it seems to be the concensus agrees with you Henk. From what I read the c version, which has the advantage of a lower noise floor, is somewhat "softer" or perhaps not as present or aggressive (?) as b version. Please don't take this as fact; I have not listened to either version.

One post I read noted that the b version is much more dependent on the individual tube, showing its character and flaws, and the c version kind of evens all of that out. Subjective vague words to try to describe an auditory experience, but alas that's what I have.

In any case, I had already decided to build the b version. And now that riggler is probably doing a round 3, it looks like I'll be able to join the party! But dang, this stuff adds UP! Just ordered a nice wooden box for it, from vintagemicrophone.com.

Thanks again Dan and Henk!

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 04, 2013, 09:23:24 AM
Henk and Dan, much appreciated!

I was trolling the 'net to find more info on b vs c, and it seems to be the concensus agrees with you Henk. From what I read the c version, which has the advantage of a lower noise floor, is somewhat "softer" or perhaps not as present or aggressive (?) as b version. Please don't take this as fact; I have not listened to either version.

One post I read noted that the b version is much more dependent on the individual tube, showing its character and flaws, and the c version kind of evens all of that out. Subjective vague words to try to describe an auditory experience, but alas that's what I have.

In any case, I had already decided to build the b version. And now that riggler is probably doing a round 3, it looks like I'll be able to join the party! But dang, this stuff adds UP! Just ordered a nice wooden box for it, from vintagemicrophone.com.

Thanks again Dan and Henk!

Mike



Dont worry i included both version in the pcb kit just to make it harder to choose  ;)

Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 04, 2013, 10:02:52 AM
Henk and Dan, much appreciated!

I was trolling the 'net to find more info on b vs c, and it seems to be the concensus agrees with you Henk. From what I read the c version, which has the advantage of a lower noise floor, is somewhat "softer" or perhaps not as present or aggressive (?) as b version. Please don't take this as fact; I have not listened to either version.

One post I read noted that the b version is much more dependent on the individual tube, showing its character and flaws, and the c version kind of evens all of that out. Subjective vague words to try to describe an auditory experience, but alas that's what I have.

In any case, I had already decided to build the b version. And now that riggler is probably doing a round 3, it looks like I'll be able to join the party! But dang, this stuff adds UP! Just ordered a nice wooden box for it, from vintagemicrophone.com.

Thanks again Dan and Henk!

Mike



Dont worry i included both version in the pcb kit just to make it harder to choose  ;)

Best,
Dan,
You're not a brat or anything.  :P
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ajemutt on October 07, 2013, 12:47:23 AM
Heya folks,

A couple questions about as I ponder jumping into this build:


#1 in looking at the photos of the build, crossing the leads from the tube to the PCB seems to make shorting likely. Is there a reason not to use heat shrink on those leads?

#2 Is there a specific case that's ideal for the PSU? (or did I miss that in the BOM lists somewhere?) EDIT: Fount it!

thanks!

AJ
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 07, 2013, 08:08:51 AM
Heya folks,

A couple questions about as I ponder jumping into this build:


#1 in looking at the photos of the build, crossing the leads from the tube to the PCB seems to make shorting likely. Is there a reason not to use heat shrink on those leads?

#2 Is there a specific case that's ideal for the PSU? (or did I miss that in the BOM lists somewhere?) EDIT: Fount it!

thanks!

AJ

#1 in looking at the photos of the build, crossing the leads from the tube to the PCB seems to make shorting likely. Is there a reason not to use heat shrink on those leads?

I personnaly dont use shrink warp on this build on the the tube leads as once they are soldered in they are very stiff and very unlikely to move or short.

Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: dmp on October 07, 2013, 12:07:44 PM

Quote
#1 in looking at the photos of the build, crossing the leads from the tube to the PCB seems to make shorting likely. Is there a reason not to use heat shrink on those leads?

I'd suggest using tubing on all the leads except the grid.
Leaving the grid open allows for easy cleaning, but with the other leads covered, you prevent a short. Having the high voltage wire exposed in particular would make me nervous.
I prefer teflon tubing over heat shrink.
http://www.redco.com/Redco-TT250.html
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 09, 2013, 11:46:49 AM
I received the boards already?  :o

Wow! thanks Dany!!! Super fast shipping!!!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 10, 2013, 02:03:07 AM
Just ordered my K7 capsule from Ben Sneesby! Parts are mounting! I got just about everything now but the mic body! riggler!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Woot on October 10, 2013, 04:02:59 AM
Group DIY - come for the amazing projects, stay for Phraze's posts...

Man you crack me up...  8)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on October 10, 2013, 10:49:45 AM
Group DIY - come for the amazing projects, stay for Phraze's posts...

Man you crack me up...  8)
Thanks Woot!  ;D :D ;)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on October 10, 2013, 12:44:24 PM
I got some Sommer Cable Octave Tube microphone cable. Its got 5 x 0,14mm2 (AWG26) and 2 x 0,5mm2 (AWG21).

Would you use the two thicker cables for pin 5 and 3?

What about the cable shield? I use a Binder connector at one end and an 7 pin XLR at the other.

Sorry for my noobish question...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: dmp on October 10, 2013, 01:15:22 PM
Use thicker wire for the heater and ground (4 & 7). The heater has the highest current, requiring the higher gauge wire.
If there is a twisted pair in the remaining 5 wires, use them for the audio (1 & 2)
I think the cable shield should be attached to the metal of the PSU connector only, but Poctop should verify that.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on October 10, 2013, 01:27:09 PM
Thank you dmp!

I'm glad i asked, i was staring at voltages but i should know better...

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Woot on October 22, 2013, 04:10:41 AM
Hi Guys,

I'm looking to buy some Galaxy Maggiorato cases for the PS for this project. Can anyone comment how deep the cases will need to be to fit everything?

The ones to choose between are:

2u x 230mm wide x 170 mm deep or
2u x 230mm wide x 230 mm deep

There is not too much difference in the price, but there may be a bit of price difference in shipping cost etc

Cheers,

Matt
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 22, 2013, 08:06:55 AM
Hi Guys,

I'm looking to buy some Galaxy Maggiorato cases for the PS for this project. Can anyone comment how deep the cases will need to be to fit everything?

The ones to choose between are:

2u x 230mm wide x 170 mm deep or
2u x 230mm wide x 230 mm deep

There is not too much difference in the price, but there may be a bit of price difference in shipping cost etc

Cheers,

Matt

I have been able to mount everything in the fantastic Dan's (dandeurloo) psu case they look very nice but i had to mount the choke on the side with countersunk screw on the face of the psu, for IMHO for 6 cm deeper i would go for it so you dont come short on space and it is probably easier to work with.

Best,
DAn,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Melodeath00 on October 22, 2013, 09:42:19 AM
Is anything changed in the PCB changed to compensate for use of the 5840 versus the AC701? Also, any insight into the 5703? I've seen that used in M49 tributes, as well as the 5744. Would any components need to be altered?

I've heard the EC1000 is noisy/finnicky, but there's also the Russian 6S6B and the 5719.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on November 23, 2013, 06:26:05 AM
Is anything changed in the PCB changed to compensate for use of the 5840 versus the AC701? Also, any insight into the 5703? I've seen that used in M49 tributes, as well as the 5744. Would any components need to be altered?

I've heard the EC1000 is noisy/finnicky, but there's also the Russian 6S6B and the 5719.
I was curious about this too...bump Dany? :)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on November 23, 2013, 09:51:01 AM
Is anything changed in the PCB changed to compensate for use of the 5840 versus the AC701? Also, any insight into the 5703? I've seen that used in M49 tributes, as well as the 5744. Would any components need to be altered?

I've heard the EC1000 is noisy/finnicky, but there's also the Russian 6S6B and the 5719.
I was curious about this too...bump Dany? :)

The only suggestion that come to mind is in the c version with the 5840 the cathode bypass cap specified at 22uf(25uf) can be replaced with a 10uf for better bass response IIRC,  still needs to be tested here.

the Psu is also full passive split choke so no issue with the B version at all , and the heater can be adjusted for proper voltage for the AC701 if you have one ,
in hand ,

Best,
Dan,


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: pasarski on November 23, 2013, 02:21:06 PM


The only suggestion that come to mind is in the c version with the 5840 the cathode bypass cap specified at 22uf(25uf) can be replaced with a 10uf for better bass response...

You mean 100uF?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on November 23, 2013, 02:33:29 PM


The only suggestion that come to mind is in the c version with the 5840 the cathode bypass cap specified at 22uf(25uf) can be replaced with a 10uf for better bass response...

You mean 100uF?

Sorry I meant C9 on the c version from 22uf to 10uf ,
best,
DAn,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: scott_humphrey on November 23, 2013, 05:55:17 PM
I believe that increasing the value of the bypass capacitor at C9 is what is needed to improve the bass response.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on November 24, 2013, 11:16:20 AM


The only suggestion that come to mind is in the c version with the 5840 the cathode bypass cap specified at 22uf(25uf) can be replaced with a 10uf for better bass response...

You mean 100uF?

Sorry I meant C9 on the c version from 22uf to 10uf ,
best,
DAn,

What Meant as Better would have meant a more Linear Bass Response,
Sorry for the confusion ,
Best
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Melodeath00 on November 24, 2013, 12:14:16 PM
Is the bass already more linear in the b version?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on November 30, 2013, 06:36:42 AM
Is the inductor in the PSU connected to X1-1 and X1-2?

There is no polarisation on that inductor, right?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on November 30, 2013, 11:00:51 AM
Is the inductor in the PSU connected to X1-1 and X1-2?

There is no polarisation on that inductor, right?

Correct,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on December 02, 2013, 03:44:43 AM
Thank you for your reply Dan.

I am quite sure i read somewhere about how to make a test load to adjust the PSU before connecting the microphone, but i can't seem to find it. Does anyone know where to find that? My PSU is hooked up and ready to go, not seeing any smoke comming from it yet :)

Also, i swapped pin 3 and pin 7 in the PSU end, is that correct?

Sorry if i am repeating questions.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on December 02, 2013, 07:54:06 AM
Thank you for your reply Dan.

I am quite sure i read somewhere about how to make a test load to adjust the PSU before connecting the microphone, but i can't seem to find it. Does anyone know where to find that? My PSU is hooked up and ready to go, not seeing any smoke comming from it yet :)

Also, i swapped pin 3 and pin 7 in the PSU end, is that correct?

Sorry if i am repeating questions.

Nop, not at the psu end , at the mic end, 
here is a reminder, 


Cabling connection From PsU https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281993f31.jpg

what you have to remember is that on the mic end pad 3 on pcb is the 0V and the pin 7 is the chassis/sheild

it actually does not matter since pad 3 and pad 7 on the mic pcb is the same but on the psu the pin 3 has the sheild lift function so if you tie this one on the 0V and lift the shlf jumper then you dont have a return ,

so in simple pin 3 from psu goes to pad 7 on pcb and pin 7 of the psu goes pad 3 on the mic pcb.

then if you have a wrong ground scheme you are aware of this distinction.

hope this helps,
Dan,
 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on December 02, 2013, 08:11:29 AM
Thank you for your reply Dan.

I am quite sure i read somewhere about how to make a test load to adjust the PSU before connecting the microphone, but i can't seem to find it. Does anyone know where to find that? My PSU is hooked up and ready to go, not seeing any smoke comming from it yet :)

Also, i swapped pin 3 and pin 7 in the PSU end, is that correct?

Sorry if i am repeating questions.

Nop, not at the psu end , at the mic end, 
here is a reminder, 


Cabling connection From PsU https://dl.dropboxusercontent.com/u/43869772/PSU%20cabling%20to%20M49%20and%20M269c.jpg

what you have to remember is that on the mic end pad 3 on pcb is the 0V and the pin 7 is the chassis/sheild

it actually does not matter since pad 3 and pad 7 on the mic pcb is the same but on the psu the pin 3 has the sheild lift function so if you tie this one on the 0V and lift the shlf jumper then you dont have a return ,

so in simple pin 3 from psu goes to pad 7 on pcb and pin 7 of the psu goes pad 3 on the mic pcb.

then if you have a wrong ground scheme you are aware of this distinction.

hope this helps,
Dan,


AH! I'm an idiot.Again. Glad i asked, thank you!

What about that test load? Tried searching and scrolling through some threads but i can't find it...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on December 02, 2013, 09:40:45 AM
Ball Park figure is <

Heater = 6V at 150ma
B+ 120V at 0.8ma



Heater
U=RI
P=VI
then Test Load = 6V/.150A = 40ohm
then P (watt) = 6V*0.150A = 0.9W then 2 watt will be fine.




B+
U=RI
P=VI
then Test Load = 120V/.0008A =150Kohm
then P (watt) = 120V*0.0008A = 0.096W then 1/4 watt will be fine.





Hope this helps,
Dan
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on December 15, 2013, 03:41:51 AM
Hi quick question Dani; I could swear at one point I saw that the puck will work with Max's BV11 - but I can't find the thread (I have looked!). I just want to make sure; I thought at one point you had said one side was for the AMI xformer and the other for the Max BV11...

Thx, sorry if this was obvious. I actually already bought the BV11 from max but when I went back to try to find the thread for some reason I couldn't.

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on December 15, 2013, 08:57:51 AM
Hi quick question Dani; I could swear at one point I saw that the puck will work with Max's BV11 - but I can't find the thread (I have looked!). I just want to make sure; I thought at one point you had said one side was for the AMI xformer and the other for the Max BV11...

Thx, sorry if this was obvious. I actually already bought the BV11 from max but when I went back to try to find the thread for some reason I couldn't.

Mike
OK sorry nevermind; I found the reference...

Does anyone know if Max's BV.11 transformer will 1) work with Dany's xfrmr pcb & 2) also fit in this M49 mic body used on said board?  Thanks!

Hi Grant ,

if you look at post #68 on this thread you will see that the transformer adaptor board has been designed in consequence to have Max transformer on it if you flip the board on on side you have Max transformer and on the other side the AMI T49 it can also be a wired transformer .

(https://dl.dropboxusercontent.com/u/43869772/D-M49BC/WMX.jpg)

i havent got a hold of Max or Max transformer yet has it has just came out but it will theoritically pop right in , and has been patched to work...

I am expecting myself to try it out soon enough .....


So it is a theoritical Yes for now,   

Let see what happens,  ;)
Best,

Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: dmp on March 20, 2014, 10:21:50 AM
Hi Poctop,
The mouser cart for the mic parts doesn't seem to be complete.
They are missing some parts I think.
The m269 cart is missing a lot as well.
Dan
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 20, 2014, 10:32:42 AM
Hi Poctop,
The mouser cart for the mic parts doesn't seem to be complete.
They are missing some parts I think.
The m269 cart is missing a lot as well.
Dan

could you explain a bit ,
LEt me know,
d
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: dmp on March 20, 2014, 10:39:57 AM
Sure,
When I load the 49 cart, I don't see the standoffs (I guess that is the only thing missing on the 49)
When I load the m269 cart, the 2n2 Wimas, R4, R7...

Not a big deal - just wondering if the carts got goofed up.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 20, 2014, 10:53:53 AM
Sure,
When I load the 49 cart, I don't see the standoffs (I guess that is the only thing missing on the 49)
When I load the m269 cart, the 2n2 Wimas, R4, R7...

Not a big deal - just wondering if the carts got goofed up.
from the top of my head ,
the M269c should be as this : 
U67 Mic parts + M269 options,

U67 Mic part :         http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=83ad963d23
M269 b or C option http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=6bb38c7d28
PSU :                       http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=532017ac2f

the BOM are read only on my side hence they should never be modified,
Let me know if this helps,
D
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: dmp on March 20, 2014, 10:57:42 AM
Ok, got it! I missed that the 67 parts needed to be ordered as well.
Sorry for the diversion
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 24, 2014, 08:33:35 AM
Ok, got it! I missed that the 67 parts needed to be ordered as well.
Sorry for the diversion

No Problem,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on April 18, 2014, 11:50:46 AM
Finally had to finish pending project that have been sitting for a very long while,

D-M49

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b23.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b30.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b41.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b52.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b63.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b74.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b85.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a06b96.jpg)

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d1402a02922.jpg)


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d028199413b.jpg)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kidvybes on April 18, 2014, 11:55:37 AM
...WOW!...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on April 18, 2014, 01:27:24 PM
I'm in trouble again...

Is that the AMI body?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on April 18, 2014, 01:34:58 PM
I'm in trouble again...

Is that the AMI body?
did not mean to :)
best,
DAn,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on April 18, 2014, 03:21:52 PM
I'm in trouble again...

Is that the AMI body?
did not mean to :)
best,
DAn,

Yes this is a body i had received from AMI 1 year ago it was about time i finish this one as i am waiting for another one from Riggler and Eric :) ;) , Now the objective is to test my reskin lab with original K47 Backplate waiting here and give it a shot :)
and then the U87 (K67-K87) same experiment........ Stay tuned...
Best,
Dan,
 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on April 24, 2014, 08:53:29 PM
I want to build the M49 "B" round version.
The pictures on page 1 show the building of the "C" version.
Are they built the same?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on April 25, 2014, 07:18:06 AM
M49b here, though not round per se:

http://groupdiy.com/index.php?topic=50834.0 (http://groupdiy.com/index.php?topic=50834.0)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: dmp on April 25, 2014, 09:27:16 AM
Quote
I want to build the M49 "B" round version.
The pictures on page 1 show the building of the "C" version.
Are they built the same?

Very similar - I've been building up the b and you just have to watch for the few components that differ.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on April 25, 2014, 10:38:36 AM
Quote
I want to build the M49 "B" round version.
The pictures on page 1 show the building of the "C" version.
Are they built the same?

Very similar - I've been building up the b and you just have to watch for the few components that differ.
+1
YeP, if you foow the Silk you wil be alright as it is the same strategy for both b, c
Best,
DAN,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on May 05, 2014, 04:45:05 PM
I would need some help with with finishing my M49B.. i feel i am really close but i think something is not right.

I measure:

PSU - H+ 6.1V (DC)
         B+ 120V

MIC - K  6.1V
         A  67.7V (will read higher values when turning R7 but not lower than this...)
         H+ 6.1V
         HG 0.03V

PAD 5 @ MIC reads 120V

PAD 6 @ MIC is 0V, 57V or 116V


Any ideas on what i could try next?  :-\
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on May 06, 2014, 03:10:06 PM
Sorry to bore everyone with this, but i need some help.

Am i thinking correctly here:

I have 100K plate resistor, 120 - 68 = 52V

Which is too low..

So to adjust the plate voltage to 50V i need to adjust the plate resistor. Right?

How do i calculate that? Or is it trial and error thing..?

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 06, 2014, 04:25:42 PM
Sorry to bore everyone with this, but i need some help.

Am i thinking correctly here:

I have 100K plate resistor, 120 - 68 = 52V

Which is too low..

So to adjust the plate voltage to 50V i need to adjust the plate resistor. Right?

How do i calculate that? Or is it trial and error thing..?

it will really be only if you put a AC701K in there that you will obtain those precise results,
this is why the self bias is a no brainer but the b is much more fun and learning, 
I have 100K plate resistor, 120 - 68 = 52V so this mean 52V drop trough 100K means 0.52ma,  U= RI
52V/100K = i in ma

here is an example,
B+ = 115V
Plate = 53V
Drop across 100k (plate resistor)
= 115-53 = 62V Voltage drop across 100k
that means the tube running at .62ma
We want about 45V on the plate to get to
the specified 0.7ma then
 
the best at this point is to replace temporarly the plate resistor with a pot lets say  250K and try to tweak both bias pot and plate resistor pot until you find the nearest condition , no one uses same tube and this is a related together and the 2 parameter are related, this is the best approach once you find the sweet spot for it you can replace the plate resistor whit with a 1/4 watt resistor ,
try that and keep me posted and let me know what the balance value you find or the nearest , what tube did you used, and make sure you try the mic first.

Let me know,
Best,
dAN,




Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on May 06, 2014, 05:54:51 PM
Sorry to bore everyone with this, but i need some help.

Am i thinking correctly here:

I have 100K plate resistor, 120 - 68 = 52V

Which is too low..

So to adjust the plate voltage to 50V i need to adjust the plate resistor. Right?

How do i calculate that? Or is it trial and error thing..?

it will really be only if you put a AC701K in there that you will obtain those precise results,
this is why the self bias is a no brainer but the b is much more fun and learning, 
I have 100K plate resistor, 120 - 68 = 52V so this mean 52V drop trough 100K means 0.52ma,  U= RI
52V/100K = i in ma

here is an example,
B+ = 115V
Plate = 53V
Drop across 100k (plate resistor)
= 115-53 = 62V Voltage drop across 100k
that means the tube running at .62ma
We want about 45V on the plate to get to
the specified 0.7ma then
 
the best at this point is to replace temporarly the plate resistor with a pot lets say  250K and try to tweak both bias pot and plate resistor pot until you find the nearest condition , no one uses same tube and this is a related together and the 2 parameter are related, this is the best approach once you find the sweet spot for it you can replace the plate resistor whit with a 1/4 watt resistor ,
try that and keep me posted and let me know what the balance value you find or the nearest , what tube did you used, and make sure you try the mic first.

Let me know,
Best,
dAN,

Thank you Dan! Great advice. I will replace R10 with a pot temporarily as you suggested and see how close I can get tweaking that and R7 bias.

My tubes are RCA branded CV3929/5840 tubes.

You wrote in the other M49 thread "and make sure you do have 58-59V on  the R6-R7 node." How exactly do I measure that?

Best Regards,

Edward

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 07, 2014, 11:48:32 AM
Sorry to bore everyone with this, but i need some help.

Am i thinking correctly here:

I have 100K plate resistor, 120 - 68 = 52V

Which is too low..

So to adjust the plate voltage to 50V i need to adjust the plate resistor. Right?

How do i calculate that? Or is it trial and error thing..?

it will really be only if you put a AC701K in there that you will obtain those precise results,
this is why the self bias is a no brainer but the b is much more fun and learning, 
I have 100K plate resistor, 120 - 68 = 52V so this mean 52V drop trough 100K means 0.52ma,  U= RI
52V/100K = i in ma

here is an example,
B+ = 115V
Plate = 53V
Drop across 100k (plate resistor)
= 115-53 = 62V Voltage drop across 100k
that means the tube running at .62ma
We want about 45V on the plate to get to
the specified 0.7ma then
 
the best at this point is to replace temporarly the plate resistor with a pot lets say  250K and try to tweak both bias pot and plate resistor pot until you find the nearest condition , no one uses same tube and this is a related together and the 2 parameter are related, this is the best approach once you find the sweet spot for it you can replace the plate resistor whit with a 1/4 watt resistor ,
try that and keep me posted and let me know what the balance value you find or the nearest , what tube did you used, and make sure you try the mic first.

Let me know,
Best,
dAN,

Thank you Dan! Great advice. I will replace R10 with a pot temporarily as you suggested and see how close I can get tweaking that and R7 bias.

My tubes are RCA branded CV3929/5840 tubes.

You wrote in the other M49 thread "and make sure you do have 58-59V on  the R6-R7 node." How exactly do I measure that?

Best Regards,

Edward

that would be more something like R8-R9 node wich is the polarisation voltage of the backplate,
always good to check, measured between R8-R9 node
not sure if it is not a typo on my end ,
Best,
Dan, <
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on May 23, 2014, 05:10:57 PM
Hi,

It didn't work out so well with my B version so I tried the C instead..

After adjusting the PSU to 120V/6,1V, without tweaking anything I had a plate voltage of 47V, so spot on! :)

Cathode was spot on 1,6V as well.

PAD 6 on the mic gave me 0-57-117V.


Time to install my capsule I think ;D
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: goneglimmering on July 26, 2014, 05:18:37 PM
Hey everyone! I'm building the PSU249P and had a quick question. There is something labeled SHLF in the PSU circuit. Can anyone clarify if that is an eq shelf like a low cut filter and if so, has anyone found it useful enough to ad a switch on the PSU to access it more easily?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Nyquist on July 26, 2014, 09:50:44 PM
Nothing to do with eq. It is a ground lift.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on September 10, 2014, 03:45:40 PM
Hi,

Here is a vocal sample of my (hopefully) finished D-49C build. The sound really is what i was hoping for when i started building this thing. What do you think?  ;D

https://soundcloud.com/kimmopeltola/d-49c-test


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: mgronroos on September 10, 2014, 10:49:59 PM
Silky, buttery, smooth...you want more, Edward..?  ;D

BTW: How many 5840s did you go through?
I'm not done with mine yet, but thinking I may get some more tubes to find a quiet one (I just have 5).

Sounds great!

//Michael
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on September 11, 2014, 01:14:32 AM
Silky, buttery, smooth...you want more, Edward..?  ;D

BTW: How many 5840s did you go through?
I'm not done with mine yet, but thinking I may get some more tubes to find a quiet one (I just have 5).

Sounds great!

//Michael

Not many, bought a kit of 5 of JAN 5480W and CV3929. This is the third tube that's in there. Burnt in for two days. The tube I had before this one actually was a little quieter but I recently changed the C5 cap and at the same time I swapped the tube.

Thanks for the comments Michael  :D
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 13, 2014, 05:50:42 PM
I'm going to give it a shot on this build as well. M49b Version. I used to have the original one, ears ago (I was young, unexperienced,... Sold it... I will regret that for the rest of my life!  ....)
. NEVER forgot the sound, and never heard similar. I built oliver's kit of U47 I'm VERY happy with.
Started collecting the parts. Got the boards, round verson, Paid Spence for the body, got couple of the JAN 5840W an the RCA ones of Ebay. Now looking for the trafo. Would like to go with AMI T49, or BV11R. I can't seem to find where I can buy those. Sent Email to AMI, No response. Do you guys know of any stock/source?
Another question is, there is also BV11A. Is that going to work with 5840? 

What I could not realize is will this boards fit into the TLM49 body?  Can Anybody confirm that? 


Love his tread! lots of good info, just red it all!

THANKS!!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Edward on September 13, 2014, 06:29:20 PM
I'm going to give it a shot on this build as well. M49b Version. I used to have the original one, ears ago (I was young, unexperienced,... Sold it... I will regret that for the rest of my life!  ....)
. NEVER forgot the sound, and never heard similar. I built oliver's kit of U47 I'm VERY happy with.
Started collecting the parts. Got the boards, round verson, Paid Spence for the body, got couple of the JAN 5840W an the RCA ones of Ebay. Now looking for the trafo. Would like to go with AMI T49, or BV11R. I can't seem to find where I can buy those. Sent Email to AMI, No response. Do you guys know of any stock/source?
Another question is, there is also BV11A. Is that going to work with 5840? 

What I could not realize is will this boards fit into the TLM49 body?  Can Anybody confirm that? 


Love his tread! lots of good info, just red it all!

THANKS!!

Hi!

Copied from AMIs web page:

BV11A  -  Direct replacement for M49/50, historically correct  -  AC701, AC701K
BV11R  -  BV11A with extended low and low-mid frequency response  -  EC92, EF732, 5840, 6072a and 12AY7WA

So for 5480 tube AMI recommends BV11R.

About availability, I'm uncertain of the current status... Read http://groupdiy.com/index.php?topic=57047.0

/Edward
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 18, 2014, 10:46:23 AM
Yes, poctop's M49b with Peluso capsule (later killed in an accident) and AMI T49 tranny, sounded absolutely gorgeous.

Which Peluso capsule was it, CEK-47 or P-K47, I just noticed there are two different ones...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 18, 2014, 12:42:28 PM
Yes, poctop's M49b with Peluso capsule (later killed in an accident) and AMI T49 tranny, sounded absolutely gorgeous.

Which Peluso capsule was it, CEK-47 or P-K47, I just noticed there are two different ones...

it was the P-47,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 20, 2014, 06:44:19 PM
On the input of my triad VP-T230-110 I'm applying 120 (that what my main is) and on the out I'm getting 136AC. Is that normal?
Im tying up on the in Blue and Violet then Gray and Brown, and on the out red-yellow and black-orange. That should be good right?

When I hook that up to the AC in of the board, with no load, just testing the power supply, I'm getting this:

B+ the lowest I can adjust with the R8  trimmer is 129.4DC
H+ the lowest I can go with the pot is 20.15DC
Polarization I can get 129.1DC for 8
                                                   64.5DC for Cardioid
                                                           0DC for omni


Is there a problem? if it is, Where should I look into?

Thanks!


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 20, 2014, 09:38:34 PM
Another Newbie question; Do you cut the pins/leads 8 and 4 off the tube?  (5840)?

Not Clear on the pictures,...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 21, 2014, 10:49:25 AM
On the input of my triad VP-T230-110 I'm applying 120 (that what my main is) and on the out I'm getting 136AC. Is that normal?
Im tying up on the in Blue and Violet then Gray and Brown, and on the out red-yellow and black-orange. That should be good right?

When I hook that up to the AC in of the board, with no load, just testing the power supply, I'm getting this:

B+ the lowest I can adjust with the R8  trimmer is 129.4DC
H+ the lowest I can go with the pot is 20.15DC
Polarization I can get 129.1DC for 8
                                                   64.5DC for Cardioid
                                                           0DC for omni


Is there a problem? if it is, Where should I look into?

Thanks!

if you have no load this is normal to see higher voltage  , this is a passive PSU,
so when the mic is connected it will load down to proper value for adjustement ,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 21, 2014, 10:50:05 AM
Another Newbie question; Do you cut the pins/leads 8 and 4 off the tube?  (5840)?

Not Clear on the pictures,...

yes you can cut them as they are redundant ,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 21, 2014, 10:52:16 AM
Thanks Poctop!!!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 21, 2014, 04:59:48 PM
Just Double check:

5840 tube:

Pin 1 to FGRID
Pin 2 to K
Pin 3 to H+
Pin 4 - Cut
Pin 5 and Pin 7 Tied together to A
Pin 6 toHG
Pin 8 - Cut

Right?

THANKS!

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 21, 2014, 05:34:27 PM
Yes this is Correct

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d02819943a0.gif)
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 25, 2014, 12:40:12 PM
Hello Everybody,

Do you know any good source for the round bodies? Just like the original ones?  Like Poctop's prototype? Where I can use it with Yokemount and Binder series 691 - 7 pin connector?

Thanks!

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 25, 2014, 01:32:41 PM
Hello Everybody,

Do you know any good source for the round bodies? Just like the original ones?  Like Poctop's prototype? Where I can use it with Yokemount and Binder series 691 - 7 pin connector?

Thanks!

Contact AMI and ask for Dennis,

or Here   http://groupdiy.com/index.php?topic=52563.0
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 30, 2014, 02:02:35 PM
Ok I got all together but the body and capsule. Still debating myself about what capsule to use.

This is the problem I have. I think my voltages are off, when I connect all together, this is what I got:

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 8.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 9.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 1.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 4.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 7.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 5.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 3.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 6.jpg)



Any Idea What got wrong?
Thanks!


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 30, 2014, 02:18:24 PM
Ok I got all together but the body and capsule. Still debating myself about what capsule to use.

This is the problem I have. I think my voltages are off, when I connect all together, this is what I got:

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 8.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 9.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 1.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 4.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 7.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 5.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 3.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build.jpg)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 6.jpg)



Any Idea What got wrong?
Thanks!

Very Very Nice Build , Congrats so far,  8)
could you let me know wich picture represent wich voltage , I can guess quite easilly but it would be so much better for this thread  8)
did you adjust each of the voltage with the corresponding Potentiometer, ex.. B+ H+, Bias Pot
as far as i can tell you are pretty smack on the value , for B+ backplate and bias what about the heater at 6.3V

What tube is it , what is the 1.68V on the psu reading ?  is this the heater voltage ?

Let me know,
Dan,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 30, 2014, 03:05:00 PM
Thanks Dan!

Voltages on the Mic:

K= 1.612V - Pic 1
A = 122.4v -  Pic 2
H+ = 1.623 - Pic 3 
Pin 5 = 123.8v - Pic 4
#4 power supply = 1.683v - Pic 5
#6 Power Supply - 059.7 - Pic 6
#5 Power Supply - 123.7v  - Pic 7


I can control A Voltage on the mic with R8, but that is the lowest it goes. 
I can control K on the mic and #4 on Power Supply with the Pot.

This is the tube I use:

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 13.jpg)

Power Supply ( Used the box before for something else,>..)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 14.jpg)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 30, 2014, 03:40:41 PM
Thanks Dan!

Voltages on the Mic:

K= 1.612V - Pic 1
A = 122.4v -  Pic 2
H+ = 1.623 - Pic 3 
Pin 5 = 123.8v - Pic 4
#4 power supply = 1.683v - Pic 5
#6 Power Supply - 059.7 - Pic 6
#5 Power Supply - 123.7v  - Pic 7


I can control A Voltage on the mic with R8, but that is the lowest it goes. 
I can control K on the mic and #4 on Power Supply with the Pot.

This is the tube I use:

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 13.jpg)

Power Supply ( Used the box before for something else,>..)

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 14.jpg)

ok disconnect the mic immediately,
the problem is the heater voltage you have no emission hence no plate current that is why the Anode voltage is so high,
i think you have issue with the wiring of the 20 VAC traffo ,
how did you configure it ,
show me how it is wired or draw a little somthing ,

only this part is suspect.
Best ,
Dan,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on September 30, 2014, 04:00:11 PM
Have A Look at this ,

Connect pin 5 and 8 to PSU PCB. ( Valid For North America )
Best,
Dan,


(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d02819943bf.jpg)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 30, 2014, 04:01:04 PM
OK, This is how I have it wired:

(http://www.audiovideowiring.com/forsale/M49b/M49b Build 15.jpg)

When Is not connected to the board I'm Getting 25.61V on 5 and 6
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on September 30, 2014, 04:18:25 PM
Have A Look at this ,

Connect pin 5 and 8 to PSU PCB. ( Valid For North America )
Best,
Dan,


(https://dl.dropboxusercontent.com/u/43869772/D-M49BC/Transfo%20H%2B.jpg)

Yep That is what I have!  Sorry i wrote 6 in the picture! 


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 09:13:36 AM


ok disconnect the mic immediately,
the problem is the heater voltage you have no emission hence no plate current that is why the Anode voltage is so high,
i think you have issue with the wiring of the 20 VAC traffo ,
how did you configure it ,
show me how it is wired or draw a little somthing ,

only this part is suspect.
Best ,
Dan,

Any other idea?

Thanks Dan for helping!

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2014, 09:19:13 AM


ok disconnect the mic immediately,
the problem is the heater voltage you have no emission hence no plate current that is why the Anode voltage is so high,
i think you have issue with the wiring of the 20 VAC traffo ,
how did you configure it ,
show me how it is wired or draw a little somthing ,

only this part is suspect.
Best ,
Dan,

Any other idea?

Thanks Dan for helping!

what is the voltage up the heater when you disconnect the mic ,
D
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 09:23:45 AM
H+ with no mic is 20.89v
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2014, 09:54:57 AM
H+ with no mic is 20.89v

then Something is Pulling too much current ,
I suggest then you install a load resistor between pin 4 and ground to rule out the psu ,
somthing like 47 ohm 1 W , you can stick it between pin 4 and gnd right in the xlr connector on the psu ,
this will load it at about 150ma for 6.3V , then you will be able to rule out the mic or psu ,

Best,
Dan, 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 10:03:15 AM
H+ with no mic is 20.89v

then Something is Pulling too much current ,
I suggest then you install a load resistor between pin 4 and ground to rule out the psu ,
somthing like 47 ohm 1 W , you can stick it between pin 4 and gnd right in the xlr connector on the psu ,
this will load it at about 150ma for 6.3V , then you will be able to rule out the mic or psu ,

Best,
Dan,

Thanks Dan. With No mic, How much voltage should I have at H+?

Is there something else wrong?  Pot Wired wrong?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2014, 10:08:30 AM
H+ with no mic is 20.89v

then Something is Pulling too much current ,
I suggest then you install a load resistor between pin 4 and ground to rule out the psu ,
somthing like 47 ohm 1 W , you can stick it between pin 4 and gnd right in the xlr connector on the psu ,
this will load it at about 150ma for 6.3V , then you will be able to rule out the mic or psu ,

Best,
Dan,

Thanks Dan. With No mic, How much voltage should I have at H+?

Is there something else wrong?  Pot Wired wrong?

you should be able to adjust the pot for 6.3V at 150ma with no mic connected and the dummy  load installed, 
if not then PSU got somthing wrong ,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 10:57:40 AM
[q
you should be able to adjust the pot for 6.3V at 150ma with no mic connected and the dummy  load installed, 
if not then PSU got somthing wrong ,
Best,
Dan,

These are the voltages following the schematic:

- After the diodes at C13 - 29.36V
- after R2  - 28.99v
- X1-2 - 28.86v
- X1-1 - 28.57v
- after R6 - 27.93v
-after R11  -  27.27v
- the lowest I can go with the POT is 19.78v

Could not find any leaky cap in the path, all the negative side of them has no voltage
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2014, 11:15:53 AM
[q
you should be able to adjust the pot for 6.3V at 150ma with no mic connected and the dummy  load installed, 
if not then PSU got somthing wrong ,
Best,
Dan,

and this is with the dummy load resistor installed ?,
dan,


These are the voltages following the schematic:

- After the diodes at C13 - 29.36V
- after R2  - 28.99v
- X1-2 - 28.86v
- X1-1 - 28.57v
- after R6 - 27.93v
-after R11  -  27.27v
- the lowest I can go with the POT is 19.78v

Could not find any leaky cap in the path, all the negative side of them has no voltage
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 11:23:56 AM
No, No dummy Load.  So 47 ohm  1w
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2014, 11:32:18 AM
No, No dummy Load.  So 47 ohm  1w

Yes Please,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 11:46:04 AM
Will Get Back. Started Session.

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 03:16:29 PM
OK!!!  With the 47Ohm 1W connected from 4 on the board to the body of the XLR I can Adjust just fine to 6.3V!! So it is the Microphone...  What should I check first?


Thanks
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 03:31:43 PM
I had wired the board 1 to 7 with the connector 1-7 corresponding.
Then the cable is wired 1 thru 7 on the corresponding one on the other side. Applied the load on the female side of the cable pins 4 and 7, with the male connected to the Powersupply, and I was able to adjust to 6.3V.

I have wired the male binder to the microphone board 1 thru 7 with reversing pins 3 and 7.  connector pin 3 is wired to the board 7 and connector 7 is wired with the board 3.  Also I do not have any capsule on the board if that matters.

Is that ok?

 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2014, 03:37:01 PM
I had wired the board 1 to 7 with the connector 1-7 corresponding.
Then the cable is wired 1 thru 7 on the corresponding one on the other side. Applied the load on the female side of the cable pins 4 and 7, with the male connected to the Powersupply, and I was able to adjust to 6.3V.

I have wired the male binder to the microphone board 1 thru 7 with reversing pins 3 and 7.  connector pin 3 is wired to the board 7 and connector 7 is wired with the board 3.  Also I do not have any capsule on the board if that matters.

Is that ok?

The capsule doesnt matter ,  if you have reversed pin 3 and 7 note that on the psu pin 3 is a sheild lift not a ground so the circuit ground should go on pin 7 , but on the mic boar it says 3 this one is reversed ,  hence make sure you have installed the jumper labeled SHLF on the psu board ,  i have made a excel spreadsheet in this thread to mention this ,
a couple of pages back ,  Let me know if you have installed the jumper SHLF specially if you have inverted it ,
Best,
DAn,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 03:54:12 PM
I had wired the board 1 to 7 with the connector 1-7 corresponding.
Then the cable is wired 1 thru 7 on the corresponding one on the other side. Applied the load on the female side of the cable pins 4 and 7, with the male connected to the Powersupply, and I was able to adjust to 6.3V.

I have wired the male binder to the microphone board 1 thru 7 with reversing pins 3 and 7.  connector pin 3 is wired to the board 7 and connector 7 is wired with the board 3.  Also I do not have any capsule on the board if that matters.

Is that ok?

The capsule doesnt matter ,  if you have reversed pin 3 and 7 note that on the psu pin 3 is a sheild lift not a ground so the circuit ground should go on pin 7 , but on the mic boar it says 3 this one is reversed ,  hence make sure you have installed the jumper labeled SHLF on the psu board ,  i have made a excel spreadsheet in this thread to mention this ,
a couple of pages back ,  Let me know if you have installed the jumper SHLF specially if you have inverted it ,
Best,
DAn,

I have the jumper, yes.

After re-checking the mic cable (Gotham GAC-7 Tube) and the Binder connectors, and make sure everything is tight, I put the things back together, and all of the sudden I got right voltages;


PowerSupply:

H+ is 6.04v
B= is 116.0v



Mic:

K is 6.08v  ?!?! ( You have it at 1.6v couple of pages back in your picture)
A is 51.8v
H= is 6.03v
on 5 on the board I got 115.8v

Beside the K voltage, I guess I'm good? 

Thanks! 

I CAN SEE My Tube GLOW  !!!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 01, 2014, 04:29:07 PM
I had wired the board 1 to 7 with the connector 1-7 corresponding.
Then the cable is wired 1 thru 7 on the corresponding one on the other side. Applied the load on the female side of the cable pins 4 and 7, with the male connected to the Powersupply, and I was able to adjust to 6.3V.

I have wired the male binder to the microphone board 1 thru 7 with reversing pins 3 and 7.  connector pin 3 is wired to the board 7 and connector 7 is wired with the board 3.  Also I do not have any capsule on the board if that matters.

Is that ok?

The capsule doesnt matter ,  if you have reversed pin 3 and 7 note that on the psu pin 3 is a sheild lift not a ground so the circuit ground should go on pin 7 , but on the mic boar it says 3 this one is reversed ,  hence make sure you have installed the jumper labeled SHLF on the psu board ,  i have made a excel spreadsheet in this thread to mention this ,
a couple of pages back ,  Let me know if you have installed the jumper SHLF specially if you have inverted it ,
Best,
DAn,

I have the jumper, yes.

After re-checking the mic cable (Gotham GAC-7 Tube) and the Binder connectors, and make sure everything is tight, I put the things back together, and all of the sudden I got right voltages;


PowerSupply:

H+ is 6.04v
B= is 116.0v



Mic:

K is 6.08v  ?!?! ( You have it at 1.6v couple of pages back in your picture)
A is 51.8v
H= is 6.03v
on 5 on the board I got 115.8v

Beside the K voltage, I guess I'm good? 

Thanks! 

I CAN SEE My Tube GLOW  !!!

Quote
I CAN SEE My Tube GLOW  !!!

Yep Always a nice Feeling on this myself
If you can see your tube glow now , you are in business with the heater voltage at 6.03V,
regarding the bias , i am guessing you arew building the M49b correct ?
try measuring between grid and Kathode then as per schematic ,
but the most important is your plate voltage that you got right
IMHO,   put a capsule and Enjoy,.
Best,
DAn,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c ?)
Post by: kmozart on October 01, 2014, 04:43:00 PM



(https://dl.dropboxusercontent.com/u/43869772/D-M49BC/M49C%20Measurement/2_2.jpg)




It is M49b. Measuring exactly like this:
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on October 01, 2014, 06:27:27 PM
Seems like the H= and K are having the same voltage now.

When I measure between HG and the K or HG and H= it is 6.20V
If I measure between Fgrid and H= and Fgrid and K it is 0.93v
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 02, 2014, 08:20:50 AM
Seems like the H= and K are having the same voltage now.

When I measure between HG and the K or HG and H= it is 6.20V
If I measure between Fgrid and H= and Fgrid and K it is 0.93v

all Normal if you are tackling the M49b , if you look a the schematic  you will understand why,.
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on October 05, 2014, 05:54:20 PM
I got an e-mail that Rigglers bodies are shipping,
I have to decide on a mic transformer using the 5840 tube.
I'd like to save some money and use the T-49, but if the BV's are better, I'll pop for those.
Any real use  comments on the BV11A, vs. BV11R vs. the T-49.

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on October 26, 2014, 05:51:36 PM
Just checking to make sure.
When using the remote pattern switching from the power supply, these two points are connected?
Is there a diagram for wiring the 7 pin XLR on the mic to the  mic's round P.S.B.s?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 26, 2014, 06:16:30 PM
Just checking to make sure.
When using the remote pattern switching from the power supply, these two points are connected?

yes they are connected this is a cardiod only switch when off.

Is there a diagram for wiring the 7 pin XLR on the mic to the  mic's round P.S.B.s?


check here for cabling hints,
https://io.groupdiy.com/file/gdiy-2017/u/39511/58d02819943e5.xlsx
best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on October 26, 2014, 07:01:56 PM
I'm going to have to open a Microsoft account to see the above link. Don't want to do it.
Any other way to get the wiring?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: mgronroos on October 26, 2014, 09:54:03 PM
Hey Winetree,

Check the enclosed pic, I too a screen dump from Poctop's Excel.
(Needed it myself.)

Cheers,

Michael
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on November 04, 2014, 12:49:14 PM
FINALLY Got the body and the Thiersch M7 Blue capsule!!!

VERY Excited!  So, where do I wire the front, back and the pole wire?   I'm missing that somehow...

THANKS!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on November 04, 2014, 01:04:35 PM
FINALLY Got the body and the Thiersch M7 Blue capsule!!!

VERY Excited!  So, where do I wire the front, back and the pole wire?   I'm missing that somehow...

THANKS!

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d02819943f4.jpg)

Best Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kmozart on November 10, 2014, 11:15:43 PM
Done!   

Microphone sounds Great!!!
I'll post some pictures and samples soon, so busy at the moment.  So far, used it on vocals, cello, and acoustic guitar and love it!

One question;

I have built a U47 out of the oliver's kit at tab-funkenwerk, and K49 capsule.  Comparing it to the D49, D49 is about 15 db lower on the output. Is that normal?

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on November 11, 2014, 08:03:56 AM
Done!   

Microphone sounds Great!!!
I'll post some pictures and samples soon, so busy at the moment.  So far, used it on vocals, cello, and acoustic guitar and love it!

One question;

I have built a U47 out of the oliver's kit at tab-funkenwerk, and K49 capsule.  Comparing it to the D49, D49 is about 15 db lower on the output. Is that normal?

Thanks KMozart glad you finally made it , coming from you is an honnor to receive such a feedback on this mic, for sure love mine as well,  yes the M49 is lower output than Oliver 47 and also it will be a little lower output with M7 instead of K47-49,
if you have built the 49c over the 49b there also a difference in output, 1 is lower output than the other can remember wih one
IIRC the 49b is a bit lower output .  it should be a little hotter then a U87i or nearby, that is what it is given that nice color as well, <
so you dont have to worry if the all the voltage are correct B+ Bias , Heater and capsule Polarisation voltage and mainly that

your transformer is hooked up right. alway good to check  ;)

Edit : if it sounds good then your transformer is hooked up the right way  ;D

Best,
Dan,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on December 09, 2014, 03:51:52 AM
Dany I have a question. On the prosound forum Oliver made the following statement about the 5840 vs the 701:

"It is a EF732 aka 5840. It is in no way similar to an AC701 but easy to obtain, most of them are usable right out of the box and the impedance matches the BV11 with a 2.2k cathode resistor.
There are at least over 500k of those tubes out there and not the best microphone tube by design, it is something that does get the job done if you just want a good sounding DIY project.

EC70, 71, EC1000, AC761, etc. ?????

There is no tube that has identical characteristics with reference to technical data, nor sound, noise, etc.

Best regards,

Oliver Archut"


(Find discussion here: http://repforums.prosoundweb.com/index.php/topic,32454.30.html (http://repforums.prosoundweb.com/index.php/topic,32454.30.html))

OK so does that mean I should use a 2.2k cathode resistor since I have a BV11 former?

If so, where/how would I wire it in, or would it replace a component on your pcbs?

Thanks in advance,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kidvybes on December 09, 2014, 11:08:03 AM
Dany I have a question. On the prosound forum Oliver made the following statement about the 5840 vs the 701:

"It is a EF732 aka 5840. It is in no way similar to an AC701 but easy to obtain, most of them are usable right out of the box and the impedance matches the BV11 with a 2.2k cathode resistor.
There are at least over 500k of those tubes out there and not the best microphone tube by design, it is something that does get the job done if you just want a good sounding DIY project.

EC70, 71, EC1000, AC761, etc. ?????

There is no tube that has identical characteristics with reference to technical data, nor sound, noise, etc.

Best regards,

Oliver Archut"


(Find discussion here: http://repforums.prosoundweb.com/index.php/topic,32454.30.html (http://repforums.prosoundweb.com/index.php/topic,32454.30.html))

...and it should also be noted that Oliver implemented that very same 732 (5840) submini in his design for the Telefunken RFK AK-47, and later his own Blackspade UM17, both mics of which he described as being U47/M49 influenced...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on December 09, 2014, 05:15:08 PM
Plus it's in many Brauner mics.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 0dbfs on December 10, 2014, 05:38:26 PM
I got an e-mail that Rigglers bodies are shipping,
I have to decide on a mic transformer using the 5840 tube.
I'd like to save some money and use the T-49, but if the BV's are better, I'll pop for those.
Any real use  comments on the BV11A, vs. BV11R vs. the T-49.

I had some T49's and then tried the BV11R. After that I have swapped BV11R's into all of my "49 mic's" except for the ones where I use Max's BV11's and I would use either Max's or the BV11R. Especially if you have installed a premium capsule.

Cheers,
jb
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on December 14, 2014, 10:15:05 PM
Hey gang I have 2 questions, probably for Dany...

1) If/when I ever pop for a real AC701, will it drop in, or will I need to adjust voltages etc?

2) I want to move to England, from USA, to be with my lovely gf. That means I want to make my DIY project PSU's Europe-friendly. I was thinking of making it dual voltage, using a switch like this: http://www.digikey.com/product-detail/en/0033.4504/486-2403-ND/641146 (http://www.digikey.com/product-detail/en/0033.4504/486-2403-ND/641146)

My question is, how hard would it be to implement something like this? Do I need to get two different torroids, and two different heater transformers as well, all within the box? Or is there a more elegant way of handling this? Sorry; I love DIY'ing but electronics and I are not always on speaking terms.

Thanks in advance,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Pip on January 04, 2015, 04:02:09 PM
So it is done X 3! Decca tree here I come.

Equinox D47 Capsule matched X 3. Max K's Transformer. Riggler and TSguys bodies. My own designed and built PCB for swapping out 5840 tubes. Yay!

See Pix. A bit of a rush job with this post sorry I will fix it up when time allows. They all sound great but now the tube selection begins!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on January 04, 2015, 04:05:42 PM
So it is done X 3! Decca tree here I come.

Equinox D47 Capsule matched X 3. Max K's Transformer. Riggler and TSguys bodies. My own designed and built PCB for swapping out 5840 tubes. Yay!

See Pix. A bit of a rush job with this post sorry I will fix it up when time allows. They all sound great but now the tube selection begins!

Wow,
Thanks For that,
this is whip Cream  8)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Pip on January 04, 2015, 04:08:41 PM
Dany I have a question. On the prosound forum Oliver made the following statement about the 5840 vs the 701:

"It is a EF732 aka 5840. It is in no way similar to an AC701 but easy to obtain, most of them are usable right out of the box and the impedance matches the BV11 with a 2.2k cathode resistor.
There are at least over 500k of those tubes out there and not the best microphone tube by design, it is something that does get the job done if you just want a good sounding DIY project.

EC70, 71, EC1000, AC761, etc. ?????

There is no tube that has identical characteristics with reference to technical data, nor sound, noise, etc.

Best regards,

Oliver Archut"


(Find discussion here: http://repforums.prosoundweb.com/index.php/topic,32454.30.html (http://repforums.prosoundweb.com/index.php/topic,32454.30.html))

...and it should also be noted that Oliver implemented that very same 732 (5840) submini in his design for the Telefunken RFK AK-47, and later his own Blackspade UM17, both mics of which he described as being U47/M49 influenced...

They are a fine tube and there are zillions available. Once again if you want to use the venerable AC701 get your wallet out as you will have to buy several and hope that one is mic grade. They run about $400.00 a piece these days.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on January 04, 2015, 04:14:00 PM
Quote
Once again if you want to use the venerable AC701 get your wallet out as you will have to buy several and hope that one is mic grade. They run about $400.00 a piece these days.

Well, you only need three.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on January 04, 2015, 04:26:21 PM
 ;)

In all seriousness. Three M49s, that is sick, man!  :o :o :o
Congrats!!!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on January 05, 2015, 03:50:13 AM
OK perhaps a basic PSU transformer question; forgive me if this is obvious.

For European connection, using the torrid:

Can connect the windings in Series for 230v for primary. Then secondary can be connected in parallel for output of ~120v?

Forgive me; I'm nervous do you have to have primary in series and secondary in series too, or can mix them as described above? I don't want to piss off any electrons or cause a fire.

Thank-you,

Mike

**EDIT Google is my friend; I found this link:

http://www.electronics-tutorials.ws/transformer/multiple-winding-transformers.html (http://www.electronics-tutorials.ws/transformer/multiple-winding-transformers.html)

Apparently this is totally fine. Could I get an Amen from Dany or some other wizard? Electricity makes me nervous! Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on January 05, 2015, 04:59:27 AM
Quote
Electricity makes me nervous!

Seems you picked the wrong hobby.  ;D

Or is it the adrenaline rush you're after?   :P
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on January 05, 2015, 05:23:45 AM
In all honesty, it makes me nervous, too.
And  you've proven to be braver than me, sofar.

BTW, a little nervousness is OK. It makes you careful, which doesn't hurt in this regard.
Too much ain't good, though. When you lose the steady hand and can't think straight anymore, it really gets dangerous.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on January 05, 2015, 11:24:21 PM
Thanks micaddict mr. cheeky! ;)

I agree; it's good to have a healthy fear or respect of this hobby. I read recently that tubes can kill, so although I've been very careful and have not gotten killed so far (I think), I will continue to have a healthy respect for what I'm doing. So I don't get deader.

You know, I could of died already and didn't know it. We're all scraping after creating clones when here in the afterlife all we hafta do is order us up a brand new M49 from the heaven factory from Mr. Neumann hisself.

Go figger!

Thanks,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on January 06, 2015, 06:24:44 AM
LOL
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on January 11, 2015, 11:44:19 PM
This is a PSU question, probably for Dany but for anyone who wants to chime in with expertise.

I'm going to put a delay-start board into the mic PSU to delay the heater for about 30 seconds. It's a cool little board, but it requires about 6VAC to run it. Also takes 200mA.

I was going to use the center tap of the H+ transformer to get about 10V and then drop it down a bit with a resistor.

My concern is that the M49 H+ takes ~100mA alone, and this delayed start circuit takes another 200mA. The transformer is rated at 300mA. Isn't this pushing it? I'll be taking the power in parallel, so A is added for parallel circuits. But still...

Will this B+ transformer be powerful enough to run both the mic H+ as well as the delay-start board? I'm not knowledgeable enough in electronics to know if this is fine, or a risk.

Any thoughts are welcome. Thank-you.

PS the delay-start board is here: http://www.kandkaudio.com/other-kits/ (http://www.kandkaudio.com/other-kits/)

Scroll down to find the board.

Thanks
Title: Euro Operation of Hammond Xformer
Post by: Phrazemaster on January 18, 2015, 08:28:43 PM
I have a question regarding the Hammond Euro xformer. I am setting up my PSU for dual voltage, with a voltage selector switch. I'm fine with the primary winding, using a voltage selector switch that handles the series or parallel configurations for the primary winding.

I'm a little confused about the secondary, however. Which output do we use for 20V for USA, and which output to use for European use to get the 20V? Dan's PSU schematic shows 20V and the Hammond Datasheet shows a 10V center tap and two 5V windings...sorry if this is basic.

Also, will I need another voltage selector switch to handle the secondary?

I want to be able to take this PSU to Europe as I'm moving to England in a few months, and I want the dual-voltage capability.

Thank-you,

Mike
Title: Re: Euro Operation of Hammond Xformer
Post by: poctop on January 19, 2015, 08:54:47 AM
I have a question regarding the Hammond Euro xformer. I am setting up my PSU for dual voltage, with a voltage selector switch. I'm fine with the primary winding, using a voltage selector switch that handles the series or parallel configurations for the primary winding.

I'm a little confused about the secondary, however. Which output do we use for 20V for USA, and which output to use for European use to get the 20V? Dan's PSU schematic shows 20V and the Hammond Datasheet shows a 10V center tap and two 5V windings...sorry if this is basic.

Also, will I need another voltage selector switch to handle the secondary?

I want to be able to take this PSU to Europe as I'm moving to England in a few months, and I want the dual-voltage capability.

Thank-you,

Mike

only the primary needs to reflect the country ,
the secondary will stay the same , the datasheet also is generic for the hammond transformer ,
so this will probably help you out , this is what it is in the real life

(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d028199449d.gif)

Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on January 19, 2015, 12:04:25 PM
Thank-you Dan, I suspected as much.

The same thing applies to the toroid transformer as well then, right?

Thank-you much..

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on January 19, 2015, 12:21:51 PM
Thank-you Dan, I suspected as much.

The same thing applies to the toroid transformer as well then, right?

Thank-you much..

Mike

not sure what your asking here ,
let me know,
D
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on January 19, 2015, 12:26:41 PM
The toroid primary can be wired in parallel or in series for 115/230 operation. I've got a dual voltage selector on the primary for that.

The secondary winding can also be wired in series or in parallel. If I understand correctly, I should wire it parallel regardless of how I wire the primary to get 115v output..

Is that correct?

The reason I was confused is when I looked online it said if you wire a transformer in series you get double the voltage for the secondary. I was confused thinking wiring primary in series 230v and not changing the secondary wiring - how you still get 115v out on secondary without changing its wiring?

Thanks; hope that was clear.

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on January 19, 2015, 12:46:14 PM
Quote
The secondary winding can also be wired in series or in parallel. If I understand correctly, I should wire it parallel regardless of how I wire the primary to get 115v output..

Correct ,
DAn,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on January 19, 2015, 01:17:34 PM
Thanks Dan; you rock man!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Indecline on January 31, 2015, 06:55:41 PM
Anyone try the TLM49 conversion yet?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Le Roux on February 25, 2015, 06:48:47 PM
Hi Dan,

I wish to make the B version.

I notice that you bridge a lot of components, even though there is a hole in the PCB.
For the B version, I should completely follow the build pics on the first page?

Thanks
Neil
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on February 26, 2015, 07:28:57 AM
Hi Dan,

I wish to make the B version.

I notice that you bridge a lot of components, even though there is a hole in the PCB.
For the B version, I should completely follow the build pics on the first page?

Thanks
Neil

it is almost identical build the stuff shown here for the c version will remain valid for b version as well
if you look at both schematic side to side you will notice that they are only menute difference for tube bias
Best,
Dan, <
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: stelin on March 05, 2015, 08:03:29 PM
Hi Dan,

I'm building the M49c version and I have a (beginners) question:
There is an connection 8, "calibration input" on the mic pcb. There is no "calibration output" on the psu pcb. What is the calibration input for and what am I supposed to do with it? What have I missed?

Thanks,
Stefan
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 06, 2015, 11:38:13 PM
Hi Dan,

I'm building the M49c version and I have a (beginners) question:
There is an connection 8, "calibration input" on the mic pcb. There is no "calibration output" on the psu pcb. What is the calibration input for and what am I supposed to do with it? What have I missed?

Thanks,
Stefan

Pin 8 calibration can be used direct at the mic pcb to inject tone or sweep for tweaking C4 and R3 feedback for advanced mic builder only,  I recommend the stock value as a starting point for those they are pretty much dead on.
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 06, 2015, 11:39:30 PM
I will have a small batch available of those round Version Pcb kit as of next Week,
if interested let me know .
thanks,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: stelin on March 07, 2015, 01:36:16 PM
Thank you, Dan.

One more question: I would like to inject a test signal into the mic board (not using a capsule) for adjusting the bias and see if there is any gain difference between different tubes.
I'm building a small faradays cage where I can burn in and test my tubes without having to solder them to the board. 
Can I just connect the signal generator directly to FGRID and HG? Does it matter that the test signal is a low impedance source?

I appreciate your help!

- Stefan


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 09, 2015, 10:43:50 AM
Thank you, Dan.

One more question: I would like to inject a test signal into the mic board (not using a capsule) for adjusting the bias and see if there is any gain difference between different tubes.
I'm building a small faradays cage where I can burn in and test my tubes without having to solder them to the board. 
Can I just connect the signal generator directly to FGRID and HG? Does it matter that the test signal is a low impedance source?

I appreciate your help!

- Stefan

yes you can do that , most of the signal gen are around 50ohm impedance IIRC mine is, so there should not be any issues with that , if you compare apples to apples there is no issues,  if you do that make sure you replace the capsule with a dummy capacitor arround 72pf willbe fine ,
Best,
DAn,

 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on March 12, 2015, 06:22:33 PM
Selling 2 AMI T49 transformers.
See Black Market
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 12, 2015, 06:36:17 PM
PCB's Kit Back in Stock,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: diylan on March 27, 2015, 08:48:17 PM
Hey everyone, I'm having some power supply issues and I'm hoping someone can help me out.

My H+ measured without the mic connected is only trimming between 20 - 27vdc! Not wanting to fry the tube, I haven't measured with the mic plugged in. My mains runs a little high (~ 125vac), and I'm measuring ~ 25vac across the transformer secondaries, but that doesn't seem like it would account for such a huge voltage at H+. My B+ also seems to be running high, trimmed to it's lowest point it's around 130 vdc.

Any thoughts?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: dmp on March 28, 2015, 12:11:58 AM
Look up the heater voltage and current, use ohms law to get a resistance, and use a power resistor of that value to sub for the tube. It might be right- tube heaters take quite a bit of current.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 28, 2015, 01:22:09 AM
Hey everyone, I'm having some power supply issues and I'm hoping someone can help me out.

My H+ measured without the mic connected is only trimming between 20 - 27vdc! Not wanting to fry the tube, I haven't measured with the mic plugged in. My mains runs a little high (~ 125vac), and I'm measuring ~ 25vac across the transformer secondaries, but that doesn't seem like it would account for such a huge voltage at H+. My B+ also seems to be running high, trimmed to it's lowest point it's around 130 vdc.

Any thoughts?

this is a full Passive Power supply so basically if you have no load to the power supply it will read much higher ,
check this thread for the proper way to test under load and adjust the Voltage,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 28, 2015, 10:44:17 AM
Ball Park figure is <

Heater = 6V at 150ma
B+ 120V at 0.8ma



Heater
U=RI
P=VI
then Test Load = 6V/.150A = 40ohm
then P (watt) = 6V*0.150A = 0.9W then 2 watt will be fine.



B+
U=RI
P=VI
then Test Load = 120V/.0008A =150Kohm
then P (watt) = 120V*0.0008A = 0.096W then 1/4 watt will be fine.




Hope this helps,
Dan
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: diylan on March 28, 2015, 08:38:27 PM
Wow, I can't believe I missed it earlier in the thread. Sorry about the redundant question!

All powered up now and everything is working great. Time to see how it sounds. Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on April 14, 2015, 02:54:03 PM
 8)

this Is Rare to See,  either you buy this or a Car

http://www.ebay.com/itm/Neumann-M249B-pair-with-consecutive-serial-numbers-/201330485060?pt=LH_DefaultDomain_0&hash=item2ee03b6744

Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: mgronroos on April 15, 2015, 06:16:56 AM
That looks like a sweet deal, Dan! 

Look at it this way; what is the car worth in 5 or 10 years, and what is a pair of 49:ers worth then?
And think of all the money you can make on your wonderful recordings with them!

So the question is, should I sell my gar and get these..?! 

I think anyone in this thread is playing with the thought..  8)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 0dbfs on April 15, 2015, 10:53:35 AM
Or you can make a couple of these DIY versions, record some excellent tracks AND get a car!

Cheers,
jb

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 13, 2015, 10:35:08 PM
Question for Dany,

I got the BV11 from Max. How do I orient it? Not sure what Pin 1 is, or which way it should go on your lovely round PCB...

Thanks,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 15, 2015, 06:19:53 PM
Hi Dany, still having trouble. I found a schematic of the BV11 pinout, but it seems to be a mirror image of what your PCB has...am I supposed to mount the BV11 on the opposite side of the silkscreening on the PCB? In other words, use the side silkscreened AMIT49?

In that case, the black dot on my BV11 would match the schematic and would seem to match your traces. If mounted on the reverse side. Have you checked this?

Can you help out? Kinda stuck. Trying to trace the traces visually but it's a bit of a tough go as I'm not an EE.

Thanks,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 16, 2015, 02:54:19 AM
Nevermind; I back-traced the board against the schematic and indeed you had it right.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 16, 2015, 07:28:36 PM
Question for anyone who built the "b" version - is there anything special about the "high z" section that's different than Dan's pix in the beginning of this build? He's got the "c" version there and I'm a little confused as to where some things go...it seems some values are different and some are not there.

Thanks for any thoughts.

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 19, 2015, 12:30:01 PM
OK I got it stuffed correctly (I think).

I've got an ac701 I got for a good deal. I wired it in, but my voltages are not what they should be. Dunno if the tube isn't good or if I screwed something up. This is the "b" version.

I've got B+ at 116v and H+ at 3.94v.

Measuring across R10, I get:  116-33 = 83v for a place current of .83mA (tad high).

With ground attached to HG, I get the following:

K = 3.94v (should be 1.6v)
A = 33.8v (should be 43v)
H+ = 3.92v (correct)

Between H+ and FGRID I get .65v. Between HG and FGRID I get .27v.

Turning trimmer R7 doesn't seem to do anything for any of the voltages above.

Scratching my head and would appreciate any input. Need to get this sorted.

Thanks,

Mike

EDIT: I should probably mention I left out C6 and R3, and set C4 to 2pF. No capsule installed and no dummy cap in place of the capsule.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 19, 2015, 12:41:18 PM
OK I got it stuffed correctly (I think).

I've got an ac701 I got for a good deal. I wired it in, but my voltages are not what they should be. Dunno if the tube isn't good or if I screwed something up. This is the "b" version.

I've got B+ at 116v and H+ at 3.94v.

Measuring across R10, I get:  116-33 = 83v for a place current of .83mA (tad high).

With ground attached to HG, I get the following:

K = 3.94v (should be 1.6v)
A = 33.8v (should be 43v)
H+ = 3.92v (correct)

Turning trimmer R7 doesn't seem to do anything for any of the voltages above.

Scratching my head and would appreciate any input. Need to get this sorted.

Thanks,

Mike

EDIT: I should probably mention I left out C6 and R3, and set C4 to 2pF.

Measuring at K direclty wont give you the 1.6V it is the difference between the Grid and the filament voltage look closely to schemo  , do you have a 2M tweaking pot or a 5K pot there ? 2M should be for the 49b, IIRC it says so looking in the BOM note from mouser Bom
(Grid(V)-K(V)) , but not if you measure K direclty , because you only read the filament voltage a this location   ;),
Let me know if this make sense ,  try tweak and check back other parameter. once you get there you can try subing the 100K plate resistor for something like 150K instead of 100K , but in term you should be able to get without that modification

hope this helps,
Best
Dan,


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 19, 2015, 12:52:02 PM
Hi Dan, thanks much for the response. It's a 2M.

I wonder if it's a bad pot; twisting it does nothing.

Suggest I replace it, or sub in a 100k resistor since I'm using an ac701?

Thanks,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 19, 2015, 01:19:20 PM
Hi Dan, thanks much for the response. It's a 2M.

I wonder if it's a bad pot; twisting it does nothing.

Suggest I replace it, or sub in a 100k resistor since I'm using an ac701?

Thanks,

Mike

what i am saying is you have to measure the Voltage difference between Grid and heater voltage to get the bias (1.6V) reading if you DMM has the right impedance to do it ,  R7 should be equal to 300K in the 49b and R10 100K ,
you can try to fit R7 first , 100K should be the righ plate resistance for this one as well,

look here :
(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281994650.jpg)

Let me know,
Best,
Dan,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 19, 2015, 02:26:09 PM
Thanks Dan. I replaced the R7 trimmer; apparently it was bad. However, I'm still only getting about .5v bias across FGRID and the H+. If I read the schematic right, that's the correct place to measure, right?

If I measure from FGRID to HG, it's about 1.9v.

Turning the trimmer doesn't change the plate voltage, which now is about 27v.

I'm wondering if this could just be a bad tube?

What would make the voltage across R10 so low, and why won't the trimmer affect it?

Thanks any other thoughts; you're the best.

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 19, 2015, 03:18:49 PM
Thanks Dan. I replaced the R7 trimmer; apparently it was bad. However, I'm still only getting about .5v bias across FGRID and the H+. If I read the schematic right, that's the correct place to measure, right?

If I measure from FGRID to HG, it's about 1.9v.

Turning the trimmer doesn't change the plate voltage, which now is about 27v.

I'm wondering if this could just be a bad tube?

What would make the voltage across R10 so low, and why won't the trimmer affect it?

Thanks any other thoughts; you're the best.

Mike

your meter may not allow to measure form this high impedance source ,
so try to aim your plate voltage the same way varying this resistor R7 and then you should have the bias pretty close ,
at least from experience when the plate voltage is right the rest follows as well since you have the same tube it should line up with it,
hope this helps,
Best,
Dan,
 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 19, 2015, 04:20:59 PM
OK I measured from FGRID to HG - got 1.6v - I think that's the wrong place to measure.

No amount of turning R7 pot changes the plate voltage. The trimmer is still good, as I checked it from the bottom of the PCB and the values change as I turn the screw.

Still only getting 28v across R10...

EDIT: added a pot in parallel to R10, and a value of about 45K makes plate voltage ~43v. I guess I'll strap a little parallel resistor onto R10 then of about 45K or so? Have to figure the maths for current...

OK that won't work; total R is roughly 31K giving very low current.

And I still I do not get right voltage on bias; about 0.5v. I have a Fluke 87 True RMS meter so I'm not sure how it's getting fooled if it is...

Any other thoughts Dan?

Could the tube be bad per se?

Thanks,

Mike

Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 19, 2015, 07:40:22 PM
Still working on this...

I replaced R10 with a trimpot and with a value of 41K, and using 120V for B+, I get 43v at plate, as per schematic value.

But then the current is too high:

120-43=77V across R10.

V=IR

I=77V/41000 = 1.9mA

This is more than double the specs. I don't want to fry her royal highness.

With using a 100K resistor at R10 as specified, I only get 28V across it, which gives me: 116v-28v=88v across R10, for a current of .88mA - closer to spec but still a bit high.

Again, trimpot R7 does not affect the plate voltage at all for some reason.

I'm seriously thinking of stuffing the "c" version now, or perhaps swapping this tube with a 5840 that I have in ample supply.

Can anyone make any suggestions? I'm stuck.

Thank-you,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 19, 2015, 10:29:45 PM
Well I guess the "technical angels" have come to my rescue!

I was trying to figure out if the 2M trimmer was working, or if it was broken - those dang things are so easy to break!

So I flipped my bad boy over and tried measuring from the bottom left two points under the pcb - the resistance varied from about 182K at the 2M position, to 0. So I knew the trimmer was working, but I realized you can't tell the right value of the trimmer with it installed. I wanted to set it to 300k per schematic. Problem was, it was a bear removing the last one, and the pcbs gets nasty after too many lifts of components.

So I used maths. I said, "the whole mic has got to be a parallel resistance with this trimmer. Let me discover the whole mic resistance."

I used 1/Rtot = 1/R1 + 1/R2

1/182K=1/Trimmer Tot (2M) + 1/R2

R2 came to 200.2K, representing the rest of the mic total resistance in series with the pot.

Armed with this, I then calculated what the trimmer would need to be to set it to 300K:

1/R? = 1/200.2K + 1/300K

R? = 120K, which represented the value the trimmer needed to measure to be set internally to 300K.

So I screwed it down to 120K and then took measurements...

OMG!

43v over the plate! Using 100k resistor, 72.5mA current!

I had used a trimpot for the 100K earlier, and had decided to set it to exactly 100K and did so. Since it worked, I replaced the pot with a 100K resistor, and I'm still getting the right values!

My guess is, the R7 trimmer is very susceptible to the IPA and the flux remover; perhaps the values it was putting out for R7 before were screwed up - because I didn't change anything! I guess simply waiting a few hours did the trick...

Anyway, I'll report back after I get the capsule in and...do the first audio test!

Thanks for your patience guys!

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 20, 2015, 01:28:02 AM
OK, it's clear my bad voltages were due to the IPA not totally dry - weird. But they are spot-on now!

Installed a BeesKneez K7.

She's gorgeous!

She sings!

She's got that magic sheen, presence, etc...

Shame we can't post mp3's here. I don't have a soundcloud account. Otherwise I'd post a sample.

Thanks to Dany and all y'all!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 20, 2015, 02:16:28 AM
Just before finishing initial testing she started humming, louder and louder...Not sure if that's the tube going, or what.

Turned her off and going to bed for now.

Night all.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 20, 2015, 08:23:32 AM
Just before finishing initial testing she started humming, louder and louder...Not sure if that's the tube going, or what.

Turned her off and going to bed for now.

Night all.

you may have to experiment with the shield wire cause you may end up with a gnd loop to mic chassis ,
try just keeping the circuit(audio) gnd and lift the shield out of the mic pcb  and try that out before you remove the tube ,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 20, 2015, 06:10:06 PM
Here's a link to a file with the buzzing in it, plus a little of me goofing off singing and talking. But you can hear the buzz at a low level in the background. In the studio, with headphones, it's LOUD, although not so loud in this sample. No processing on this, except normalizing.

https://www.dropbox.com/s/1fyow5e3kod9mff/M49%20Buzzing-Track%202.wav?dl=0 (https://www.dropbox.com/s/1fyow5e3kod9mff/M49%20Buzzing-Track%202.wav?dl=0)

I did try lifting the jumper in the psu but that didn't help. But again, this noise did not appear until a few hours after using the mic. Prior to that, it was very quiet. Does this sound like tube noise? Or shielding/grounding? Or do I need to reconnect a connection?

Dany suggested maybe resolder a grid connection; I may try redoing the capsule connections tonight and report back. But suggestions are welcome.

So close...such a lovely sounding mic!!!

Here's a pic of the grounding scheme I used in the mic itself. Is this OK?

Thanks.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on May 21, 2015, 10:24:54 PM
I'd like to use the AMI BV 11r in this build. Being a P.S.B. transformer how would mounting  be possible?
How could it be wired?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 21, 2015, 10:32:09 PM
I'd like to use the AMI BV 11r in this build. Being a P.S.B. transformer how would mounting  be possible?
How could it be wired?

you mean the AMI BVr11r is wire transformer ? or circuit mouting with pins
Let me know,
Dan,
if it is wired , just hook it up to the second deck with the wires,  follow schematic for pinout of this transformer and color code
Best,
Dan,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 24, 2015, 09:15:55 PM
Question gang, could a bad tube cause low plate voltage?

I've been wracking my brains on my build; at first the plate voltage was only 28v. This after lots of cleaning with IPA and flux remover. Then after it dried really well the plate voltage rose to 43V or so.

I was getting a noise issue, so I ended up replacing a couple of components to try to solve it, and also used more IPA. After that, the plate voltage was again low to 28v or so, but rose steadily as it totally dried again to 43v.

Still having the noise issue, I replaced another component and again cleaned the board. The voltage dropped to 27v or so, but I though no big deal; there's just some residual IPA somewhere, maybe in R7 or something.

Thing is, it's never recovered. Now plate voltage is about 27v and I've now replaced many other components to try to figure this things out. I've also reflowed all solder joints.

Turning R7 doesn't make any difference; I replaced it and still no joy.

Could I have a bad tube? It was expensive; I hate to take it out, but I could. I'm about ready to rebuild the main PCB with all new parts, and hopefully there was a cold joint or some bad component in some fashion. Just hope not the tube.

Anyway, could a bad tube cause a low plate voltage? And why would it react that way, going in/out of spec, with basic cleaning of IPA?

Thanks; I'm getting frustrated as I can't seem to find the fault.

Best,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: justgold on May 28, 2015, 10:41:22 PM
SO CLOSE to being finished with my build! Two quick questions:
1.  Does anyone have specific spec on the standoffs? I need to order a few to round things out but want to get it right the first time!
2.  I have a Neumann K49 capsule that will eventually go in this build, but I'm uncertain of what the proper capsule holder would be as well as dialing in the correct height - any suggestions?
Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: vinylwall on June 30, 2015, 08:20:47 PM
I picked the majority of these parts up from "justgold".  Oliver Archut AMI M49 Alternative Kit.  New AMI M49 metalwork (body), AMI made PSU, Neumann K47fet capsule, Sylvania NOS 5840 Tube, AMI T49 transformer, Dany's D-49 PCB's.  "justgold" had most of the PCB's already built.  I finished off the complete build (M49c version), and she sounds great.  I still need to raise the capsule higher a bit:
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: vinylwall on June 30, 2015, 08:21:15 PM
Assembled M49c:
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: vinylwall on June 30, 2015, 08:21:41 PM
Oliver's PSU for this build:
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 05, 2015, 06:56:46 PM
Still can't figure out grounding. Is my diagram right?

I'm redoing this mic from the ground up and I would love to know how to ground in the mic properly. I got buzzing before.

Comments from those who have built this successfully? Pic attached.

Thanks,

Mike

Here's a link to a file with the buzzing in it, plus a little of me goofing off singing and talking. But you can hear the buzz at a low level in the background. In the studio, with headphones, it's LOUD, although not so loud in this sample. No processing on this, except normalizing.

https://www.dropbox.com/s/1fyow5e3kod9mff/M49%20Buzzing-Track%202.wav?dl=0 (https://www.dropbox.com/s/1fyow5e3kod9mff/M49%20Buzzing-Track%202.wav?dl=0)

I did try lifting the jumper in the psu but that didn't help. But again, this noise did not appear until a few hours after using the mic. Prior to that, it was very quiet. Does this sound like tube noise? Or shielding/grounding? Or do I need to reconnect a connection?

Dany suggested maybe resolder a grid connection; I may try redoing the capsule connections tonight and report back. But suggestions are welcome.

So close...such a lovely sounding mic!!!

Here's a pic of the grounding scheme I used in the mic itself. Is this OK?

Thanks.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 05, 2015, 07:35:00 PM
Or would the following scheme be better? Or something different?

Anyone?

Thx.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on July 05, 2015, 07:38:14 PM
Or would the following scheme be better? Or something different?

Anyone?

Thx.

use only from psu pin 7 to mic pcb pad 3
and do not use psu pin 3 to mic pcb pad 7

let me know how this works
Best,
Dan,


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 05, 2015, 09:14:25 PM
Many Thanks Dany.

So I've attached one more photo with two versions; which would be better?

It seems version 2 would avoid a ground loop, but then the schematic shows a connection to the shield from the mic...Or is there yet another way of doing this?

I thought I saw pix with people having a connection from the mic PCB to the chassis...did my eyes wrong me?

Thanks a million,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 08, 2015, 09:50:32 PM
Many Thanks Dany.

So I've attached one more photo with two versions; which would be better?

It seems version 2 would avoid a ground loop, but then the schematic shows a connection to the shield from the mic...Or is there yet another way of doing this?

I thought I saw pix with people having a connection from the mic PCB to the chassis...did my eyes wrong me?

Thanks a million,

Mike

Bump? Anyone tried either of these schemes? Which is better?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on July 09, 2015, 10:36:23 AM
Many Thanks Dany.

So I've attached one more photo with two versions; which would be better?

It seems version 2 would avoid a ground loop, but then the schematic shows a connection to the shield from the mic...Or is there yet another way of doing this?

I thought I saw pix with people having a connection from the mic PCB to the chassis...did my eyes wrong me?

Thanks a million,

Mike

Bump? Anyone tried either of these schemes? Which is better?

it might depends on the RF environnement of the mic ,
somtimes it is better to lift the shield of the cable to prevent issues ,
somtimes it is best the other way , that is why i had a sheild lift jumper option on most of my psu ,

hope this helps,
still no luck ?
Best
Dan,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 09, 2015, 05:38:54 PM
Thanks Dan.

Haven't finished yet.

Of the two I posted, which version would you try first?

Thanks man,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on July 10, 2015, 09:28:59 AM
Thanks Dan.

Haven't finished yet.

Of the two I posted, which version would you try first?

Thanks man,

Mike

the version with no shield attached to ground ,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 10, 2015, 10:56:35 AM
Thanks Dan.

Haven't finished yet.

Of the two I posted, which version would you try first?

Thanks man,

Mike

the version with no shield attached to ground ,
Dan,

Thanks Dan.  Neither Version 1 nor Version 2 here have the shield attached to the ground.

Of these two, I was thinking Version 1 is better. It looks like that's what you used. Am I right?

But that also means that the shield wire in the cable is left floating. Is that OK?

Thanks,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on July 10, 2015, 11:49:41 AM
Thanks Dan.

Haven't finished yet.

Of the two I posted, which version would you try first?

Thanks man,

Mike
nope it can be star grounded to psu ,  and still be efficient ,
Best,
Dan,


the version with no shield attached to ground ,
Dan,

Thanks Dan.  Neither Version 1 nor Version 2 here have the shield attached to the ground.

Of these two, I was thinking Version 1 is better. It looks like that's what you used. Am I right?

But that also means that the shield wire in the cable is left floating. Is that OK?

Thanks,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 12, 2015, 01:33:09 AM
Thanks Dany. I decided to leave the #3 shield wire connected to the mic chassis/housing, and didn't connect the shield to the PCB at all. So the shield is tied to the mic housing. Basically Version 2 from my previous drawings. I accidentally didn't switch 7 and 3, as per instructions, but since they are both connected on the PCB on the ground plane, and I wasn't connecting both 7 and 3 to the cable, I don't think it matters (no noise noted).

But the big new is...

It works!

Got an original AC701K in there...sounds amazing! Thought I had fried it...all kinna weird things going on the with the last build; could never figure it out, and I'm always really meticulous on my builds too. Dany told me I had Gremlins. lol! Sigh,

I had to totally redo the mic - and Dany helped me immensely with pointers, and I started over with a new board. This time I put all premium parts - ALL styroflex caps (big mo-fos!), and Ohmcraft, Shinkoh, Vishay Bulk foil resistors...

The rebuild sounds even more open, clear, and natural than the first. And, it seems to be stable! I used the mods of removing R3, and a cap (C6?) too, to eliminate bass and high frequency rolloff. Mic sounds very full and "present." Note this is the "b" version.

This has been a huge, huge, HUGE labor of love, spanning over a year at least, with many months of grinding on it. I used to tell my friend I was "going to the rock pile" when working on this mic because I had added to the original PSU design and it was horrifically complicated, including adding a built-in voltmeter and dual voltage for England, where I want to move. The metal work,  the drilling, the aluminum dust...I used a FleA housing, so I had to totally innovate to attach Dan's PCB which involved making a custom bracket (nightmare...WEEKS!!!!)...

So I will try to post some pix soon, but a big shout out to Dany and everyone else who helped out!

Here's a pic of the last build, and a partial of the new one. New one has the huge styroflexers. )Old one is dirty because I didn't clean it after taking it out.)

Best,

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 12, 2015, 05:17:23 AM
Stinkin' metal work! Arg! Bracket...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 12, 2015, 05:18:48 AM
FleA body...dark drama shot.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 12, 2015, 05:22:46 AM
PSU shot...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 13, 2015, 02:58:29 PM
Say, is there anyone in the Orange County/LA area who built one of these with a binder at the PSU who might want to help me troubleshoot some hum?

Mic sounds amazing, but my fancy PSU I think may be introducing some hum. If I could just try it with someone else's PSU it would clear up a lot...

Let me know, and thanks.

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on July 13, 2015, 06:32:50 PM
I have 2- M49 power supplies with binder connectors with cables.
I haven't finished the mics just but I've tested the supplies.
I'm in Irvine on the weekends. Where are you?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 13, 2015, 09:10:06 PM
Awesome Winetree; PM sent!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Winetree on July 20, 2015, 05:21:37 PM
Quote " I suggest then you install a load resistor between pin 4 and ground to rule out the psu ,
somthing like 47 ohm 1 W , you can stick it between pin 4 and gnd right in the xlr connector on the psu ,
this will load it at about 150ma for 6.3V , then you will be able to rule out the mic or psu , "

Best,
Dan,


Dan,
I'm using your P.S. board with a real Neumann AC701 M49. I need need to set the voltage to 4.0 volts.
Should I use the same dummy load 47 ohm between pin 4 and Ground to pre test the voltage?
Will your boards go down to 4 volts or will I have have to change some parts?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on July 20, 2015, 05:53:25 PM
Hi Winetree,

That's cool but I'm not ready to desolder/muck about with/ stuff just yet...hopefully we can still test this on Saturday?

Thanks man.

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on July 21, 2015, 07:18:55 AM
Quote " I suggest then you install a load resistor between pin 4 and ground to rule out the psu ,
somthing like 47 ohm 1 W , you can stick it between pin 4 and gnd right in the xlr connector on the psu ,
this will load it at about 150ma for 6.3V , then you will be able to rule out the mic or psu , "

Best,
Dan,


Dan,
I'm using your P.S. board with a real Neumann AC701 M49. I need need to set the voltage to 4.0 volts.
Should I use the same dummy load 47 ohm between pin 4 and Ground to pre test the voltage?
Will your boards go down to 4 volts or will I have have to change some parts?

if you have used a 250ohm trimmer pot as suggested a while ago you will be fine ,
then use ohms law to calculate the dummy load and then the power ,
it should give 40 ohm (so 47 ohm should be near by) ohm at 100ma  , and about  between 0.5 to1 W will suffice,
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on August 12, 2015, 09:50:26 AM
Added Picture for connection of Capsule and clarification o Floating connection Scheme both version and also the Cardiod only Switch ,

See page 1 and also Check Andriejus thread For upcoming Microphone Body
http://groupdiy.com/index.php?topic=60108.msg762707#new
Best
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Bowie on September 19, 2015, 02:20:20 AM
Hi!  Could someone advise as to the tonal influence that the composition of the C1 capacitor has in the mic (1nf which sits between front and rear diaphragms in the circuit).  I ask because I used a silver mica in my mock-up/test mic but have some very healthy Sprague Vitamin Q PIOs which I usually prefer the sound of.   I've read that C2 and C3 are influential but found no mention of C1 making a difference.  Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Banzai on September 20, 2015, 12:19:29 AM
It's a key part: Polystyrene caps are the period accurate choice, but because they suffer from microphonics, some – strongly – argue to use an NP0/CG0 ceramic cap instead...

If it was my mic, I'd replace the mica, and try out both Polystyrene and your Sprague PIO to hear the differences. Sound being sound, if you like what the PIO does, then there is no right and wrong: use that instead ;). If you want it to be period accurate, stick to Polystyrene. Just make sure to keep the leads short and the cap body glued to the board to help with the microphonics.

Hi!  Could someone advise as to the tonal influence that the composition of the C1 capacitor has in the mic (1nf which sits between front and rear diaphragms in the circuit).  I ask because I used a silver mica in my mock-up/test mic but have some very healthy Sprague Vitamin Q PIOs which I usually prefer the sound of.   I've read that C2 and C3 are influential but found no mention of C1 making a difference.  Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Bowie on September 20, 2015, 12:46:38 AM
It's a key part: Polystyrene caps are the period accurate choice, but because they suffer from microphonics, some – strongly – argue to use an NP0/CG0 ceramic cap instead...

If it was my mic, I'd replace the mica, and try out both Polystyrene and your Sprague PIO to hear the differences. Sound being sound, if you like what the PIO does, then there is no right and wrong: use that instead ;). If you want it to be period accurate, stick to Polystyrene. Just make sure to keep the leads short and the cap body glued to the board to help with the microphonics.

Hi!  Could someone advise as to the tonal influence that the composition of the C1 capacitor has in the mic (1nf which sits between front and rear diaphragms in the circuit).  I ask because I used a silver mica in my mock-up/test mic but have some very healthy Sprague Vitamin Q PIOs which I usually prefer the sound of.   I've read that C2 and C3 are influential but found no mention of C1 making a difference.  Thanks!

Thanks Banzai!  That's going in my collection of M49 notes.  Without access to an original capsule or transformer I'm not hung-up on it being period-correct.  I haven't been wild about ceramic caps in the past but I have some Polystyrenes I can compare with the VitQ.  Just wanted to make sure it was a position in the circuit that has a noticeable impact.  Thx again.  :)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Banzai on September 20, 2015, 02:48:39 AM
Let us know what you hear as difference! I'm as guilty as the next to just sticking with what's 'correct' instead of experimenting, so genuinely curious.

Thanks Banzai!  That's going in my collection of M49 notes.  Without access to an original capsule or transformer I'm not hung-up on it being period-correct.  I haven't been wild about ceramic caps in the past but I have some Polystyrenes I can compare with the VitQ.  Just wanted to make sure it was a position in the circuit that has a noticeable impact.  Thx again.  :)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: pzjones on October 06, 2015, 02:45:03 PM
Well I have decided to bite the bullet and start a M49 build. We recently used a 49c to record a really talented singer from New York who specifically asked for one for the sessions. The sessions were in the UK and we managed to hire one from Tad Barker who still has some ex Tickle Hire stock. Anyway to cut a long story short I loved the sound of the mic and decided to try to build my own which would be a bit of a challenge and let me get to learn a bit about the way the mic was made. I have bought the  round PCB,s from Dany....many thanks for your swift delivery and excellent boards and have just finished the PSU which is working and after putting a dummy load on it is providing the correct voltages. Planning on a 49B using a BV11 with a 5840 and a Neumann capsule although like all best laid plans this might change. Body from Andrew I think and making up a cable using Gotham Cable and Binder connectors. Thanks for all the help I have gleaned from the threads already, I am sure there is a lot more reading to come. I have attached a quick pic of the PSU.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on October 21, 2015, 04:03:02 PM
Hi All,  I tought I would share this with everyone , this is a Raw Picture content pictorial of the Prototype I have built for Andriejus.
While Andriejus is Polishing the Last details ,

Tip #1 always keep the lead of the HZ bridging component so you can use them to make the bridging so no need of fancy jumper and so much easier , this is build needs to be built from the top and down , except for the headbasket and capsule mount, well this is how I do it  ;)

I am hoping you will appreciate it , this also applies to the General Build of this one ,

So here it is
https://io.groupdiy.com/file/gdiy-2017/u/39511/58d02819947c9.zip?dl=0

Best,
Dan,

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: duantro on April 11, 2016, 12:29:48 PM
Hi, I purchased an AMI m49 body and it appears that your pcbs are slightly smaller than their body mounting holes. I think I may just go with the AMI plexi boards and do a point to point build, unless I can think of any other options. Does anyone have any experience or opinions on the choice between a max bv11 or an AMI bv11a (classic)? I'm using a telefunken ac701k tube also.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: achase4u on May 03, 2016, 02:08:52 PM
Looking for a replacement for the Vishay that is no longer available at Mouser...

http://www.mouser.com/ProductDetail/Vishay/V-730P105X9250/?qs=%2fha2pyFadug6OqOJv9KYiLUiFihsz700ppmOrT0UPKP6afZ0mrDRZg%3d%3d (http://www.mouser.com/ProductDetail/Vishay/V-730P105X9250/?qs=%2fha2pyFadug6OqOJv9KYiLUiFihsz700ppmOrT0UPKP6afZ0mrDRZg%3d%3d)


This is a good replacement, yes? http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKT1813510255/?qs=sGAEpiMZZMv1cc3ydrPrF9YnoK4MhZ%252buq9jXZORPslk%3d (http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKT1813510255/?qs=sGAEpiMZZMv1cc3ydrPrF9YnoK4MhZ%252buq9jXZORPslk%3d)

or does it need to be polypropylene like this one http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1839510254/?qs=sGAEpiMZZMv1cc3ydrPrF%252b30hQTSgFppYCIOtfhoJws%3d (http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1839510254/?qs=sGAEpiMZZMv1cc3ydrPrF%252b30hQTSgFppYCIOtfhoJws%3d)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on May 16, 2016, 12:32:44 PM
Looking for a replacement for the Vishay that is no longer available at Mouser...

http://www.mouser.com/ProductDetail/Vishay/V-730P105X9250/?qs=%2fha2pyFadug6OqOJv9KYiLUiFihsz700ppmOrT0UPKP6afZ0mrDRZg%3d%3d (http://www.mouser.com/ProductDetail/Vishay/V-730P105X9250/?qs=%2fha2pyFadug6OqOJv9KYiLUiFihsz700ppmOrT0UPKP6afZ0mrDRZg%3d%3d)


This is a good replacement, yes? http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKT1813510255/?qs=sGAEpiMZZMv1cc3ydrPrF9YnoK4MhZ%252buq9jXZORPslk%3d (http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKT1813510255/?qs=sGAEpiMZZMv1cc3ydrPrF9YnoK4MhZ%252buq9jXZORPslk%3d)

or does it need to be polypropylene like this one http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1839510254/?qs=sGAEpiMZZMv1cc3ydrPrF%252b30hQTSgFppYCIOtfhoJws%3d (http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1839510254/?qs=sGAEpiMZZMv1cc3ydrPrF%252b30hQTSgFppYCIOtfhoJws%3d)

For a total of $8, buy them both. See which one you prefer. Make sure you have the room if there is a size difference.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: achase4u on May 16, 2016, 12:39:29 PM
Looking for a replacement for the Vishay that is no longer available at Mouser...

http://www.mouser.com/ProductDetail/Vishay/V-730P105X9250/?qs=%2fha2pyFadug6OqOJv9KYiLUiFihsz700ppmOrT0UPKP6afZ0mrDRZg%3d%3d (http://www.mouser.com/ProductDetail/Vishay/V-730P105X9250/?qs=%2fha2pyFadug6OqOJv9KYiLUiFihsz700ppmOrT0UPKP6afZ0mrDRZg%3d%3d)


This is a good replacement, yes? http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKT1813510255/?qs=sGAEpiMZZMv1cc3ydrPrF9YnoK4MhZ%252buq9jXZORPslk%3d (http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKT1813510255/?qs=sGAEpiMZZMv1cc3ydrPrF9YnoK4MhZ%252buq9jXZORPslk%3d)

or does it need to be polypropylene like this one http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1839510254/?qs=sGAEpiMZZMv1cc3ydrPrF%252b30hQTSgFppYCIOtfhoJws%3d (http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1839510254/?qs=sGAEpiMZZMv1cc3ydrPrF%252b30hQTSgFppYCIOtfhoJws%3d)

For a total of $8, buy them both. See which one you prefer. Make sure you have the room if there is a size difference.

Ok - good deal!  Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: achase4u on May 16, 2016, 05:57:24 PM
Question:

In your PSU, Dan, you leave space/raise the Fairchild diodes so they sit above the PCB.  Is this necessary for noise or heat?  Or can they lie flush like a resistor?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on July 03, 2016, 04:46:18 PM
Hi All, Proudly Presenting the Cinemag BV11 Transformer Many thanks To Dave at Cinemag to take the challenge.
for all  DIY Microphone Requiring a BV11 Style Transformer  8)

For All information about this transformer and ordering
http://cinemag.biz/contactus/contact_us.php

The Cinemag CM-6511 ( BV11 Mic output X-Transformer)
(https://dl.dropboxusercontent.com/u/43869772/Cinemag%20CM-6511%20BV11.JPG)

Connection
(https://io.groupdiy.com/file/gdiy-2017/u/39511/58d0281994926.jpg)

For All information about this transformer and ordering
http://cinemag.biz/contactus/contact_us.php
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: achase4u on July 03, 2016, 09:43:24 PM
Hi All, Proudly Presenting the Cinemag BV11 Transformer Many thanks To Dave at Cinemag to take the challenge.
for all  DIY Microphone Requiring a BV11 Style Transformer  8)

For All information about this transformer and ordering
http://cinemag.biz/contactus/contact_us.php

The Cinemag CM-6511 ( BV11 Mic output X-Transformer)
(https://dl.dropboxusercontent.com/u/43869772/Cinemag%20CM-6511%20BV11.JPG)

Connection
(https://dl.dropboxusercontent.com/u/43869772/Cinemag%206511%20%20%28BV11%20%29%20%20%28M49%20Transformer%29.jpg)

For All information about this transformer and ordering
http://cinemag.biz/contactus/contact_us.php

Wow!  Going to have to try one in my other build!  Two m49s - one with AMI bv11 and C type board, and one with B type board and cinemag BV11.  I love flavors!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on November 06, 2016, 04:02:42 AM
Hi Dany, did you come to any conclusions about the x-formers you used, Cinemag vs. Ami?

Also, I could not get any information on the Cinemag. I used their contact form but got no response. Are they still selling it, and is it a faithful recreation of the original? Price?

Thanks!

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: North on December 12, 2016, 09:27:33 PM
If anyone has any leftover TLM49 innards, you can send them my way   :)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on December 12, 2016, 11:14:07 PM
If anyone has any leftover TLM49 innards, you can send them my way   :)
Like maybe a spare real Neumann capsule for instance?  ;)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: North on December 14, 2016, 07:19:00 AM
Haha ... I was thinking just the electronics ....
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on January 16, 2017, 05:31:24 PM
Troubles biasing my M49b. I finally got the plate current close and the grid bias at 1.6V. Only issue is the load resistor (R10) is at 56kΩ and the plate voltage is jumping all over.

Is 56kΩ too small for a load resistor? What could be causing the voltage to jump around?

Used Dany's PSU board with choke but bought AMI mic body which meant I had to go point to point.

I bought three rando 5840s from Bowie and one that he tested. I wired up the mic with one of the untested ones and a 100pF cap in place of each capsule in case I made a fatal mistake. My plan was to get numbers where I want them with the first tube then replace it with the tested tube and readjust.

First crack, I had plate current of 0.47mA:

R10=100kΩ
V across R6=1.6V
V plate = 69V
B+ (measured at R10) = 116V
V across R10 = 47V
H+ (measured at Cathode) = 5.6V

I connected a 250k pot with a 56k resistor in series (so I didn't accidentally make R10 = 0Ω). Making R10 higher than 100k decreased plate current . When the pot was at zero (R10=56k), I had a plate current of 77mA but jumping around:

B+ = 113V
V R10 = 37V-49V (bouncing)
V R6 = 1.6V
H+ = 5.9V
R10 = 56k Ω

I didn't adjust the power supply. I'm not sure why the H+ changed. Not exactly worried about that right now.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on January 31, 2017, 11:53:34 PM
Switched tubes and found better results for voltages. Fired up the mic and had very quiet signal and a good amount of noise. Got frustrated troubleshooting on acrylic decks (hard to clean tags, hard to swap components). I also wasn't happy with how clean the build was and suspected my wiring. I tore the mic down and rebuilt it with Dany's boards yesterday.

Fired it up today and boom its output is right where it should be. I recorded a few bias settings quickly but only @ 1.65V I had the body screws in. You can really hear the noise without the screws. I was just trying to get a rough idea on where to go as it's time consuming setting the bias and putting everything back together for a test.

I'm not sure which one I like the most from a spoken test. I recorded myself singing with the Bias set to 1.34V (plate current 0.73mA) and I like it but I think I'll be pulling C6 to try and open it up a bit.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 08, 2017, 08:40:01 AM
After a multi-day burn in, most noise is gone (H+ @ 6.3V for burn in). I re-set the bias at around 1.2V to get 0.73mA plate current. H+ at 6.0V and B+ 116V.

I removed C6 and the mic really opened up. I removed C4 since Cag of AC701 is 2.2pF adding 8pF to feedback makes sense. The 5840 is 30pF so adding another 8pF seemed excessive. It sounded a lot better with C4 removed. I then added 2pF at C4. It seems that some external feedback is better than none. The mic seems more linear with the 2pF cap in there. It's a Silver Mica but I'll replace it with a ceramic on my next Mouser order.

I ended up putting a 100pF ceramic in C6. It feels better singing into the mic without any C6 but on playback sounds a little untamed.

**************************************
If I were to build another M49 (with 5840) I'd start with C4=2pF and C6=100pF set the bias very roughly and burn the tube in for days. I'd then play with the bias and component changes. I really threw myself for a loop by trying to get the bias close before the tube was burned in.
**************************************

I also need to try swapping output caps. I have a 0.47uF MP in there. Sounds great but it's probably not wise to stick with the first output cap without trying others.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on February 08, 2017, 09:13:16 AM
Quote
It feels better singing into the mic without any C6 but on playback sounds a little untamed.

One of the reasons why singers like the Sony C800g and Manley Ref/Gold so much is because of the extra treble they hear on their cans.  The singer him- or herself hears a lot of low/mid through bone conductance and the extra treble fills this out nicely. It gives  extra clues and confidence.
But for the listener it's different, of course.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 08, 2017, 07:35:09 PM
One of the reasons why singers like the Sony C800g and Manley Ref/Gold so much is because of the extra treble they hear on their cans.  The singer him- or herself hears a lot of low/mid through bone conductance and the extra treble fills this out nicely. It gives  extra clues and confidence.
But for the listener it's different, of course.

Makes sense to me! I'm no singer but I felt like a superstar singing into the M49 with C6 removed!

With my M49 parts I finally ordered other feedback cap values for my DIY U67 and compared 100pF (stock) 10pF and no C17. I found the same thing. It felt the best to sing through the mic with no C17 but decided on 10pF listening to playback.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on March 10, 2017, 07:52:22 PM
More changes. I got a new bag of goodies from Mouser and settled on C6 270pF and C4 1pF. Both ceramics.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on March 21, 2017, 04:28:55 PM
Hello Dan!

All the content from your Dropbox is missing, do you have a way of making it available again?
That would be terrific!

Cheers

Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on March 21, 2017, 08:10:32 PM
it will come back slowly,
hang in there folks ,
actually all of my threads and build thread will come back
Best,
Dan,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: wlinart on April 10, 2017, 04:54:27 AM
Does anyone have any experience in modding the TPS100 style PSU for this microphone? What are the necessary mods?

Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: wlinart on April 13, 2017, 10:22:20 AM
Does anyone have any experience in modding the TPS100 style PSU for this microphone? What are the necessary mods?

Thanks!

I found a schematic of the aphex 460, which apparently is almost the same power supply. Am i right in assuming that changing the zeners for the B+ to the right values will be enough? I would change them to 1N4782A (82V) and 1N4754A (39V)? Or maybe a 1N4753A (36V)?

Thank you!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: trans4funks1 on April 26, 2017, 07:20:44 PM
Hi Dany,
 Are there any component value changes to the original Neumann circuit that are made to accommodate a 5840 tube instead of the AC-701?

 Thank you.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on April 26, 2017, 10:18:43 PM
Can't give you a definitive list, but I used a real AC701K with Dany's board. All I did was adjust the PSU heater to 3.85V. It was hard to calibrate it but it does sound terrific!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: useme2305 on April 27, 2017, 03:17:29 AM
what do you mean by adjust the PSU heater to 3.85V?
i thought danny's boards are ready for the AC701?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on April 27, 2017, 04:40:16 AM
His boards are for using a 5840 sub-mini tube. The 5840s use a 6.2V heater.

You'll blow your AC701 very quickly at anything over 4V on the heater.

The good news is that's easy to adjust the PSU. The bad news (for me) was I had a heck of a time setting the other voltages - not sure why. Dany told me I had a gremlin in the mic after he helped me troubleshoot, so I rebuilt it with a new board and got it working. You'll have to figure out how to wire the AC701 because Dany's instructions are for the 5840.

Do NOT wire up the AC701 and turn on the mic without  having first gotten your PSU heater voltage calibrated with a dummy load to 3.8 ~ 3.9V. If memory serves the dummy load was 40K but look through this thread and Dany already answered this one.

Good luck!

Mike
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: useme2305 on April 27, 2017, 04:49:03 AM
oh, i didn't know that. thanks for clearing that up.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on April 27, 2017, 05:15:16 AM
Welcome :)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: useme2305 on April 27, 2017, 05:20:31 AM
has anyone tried a 6S6B with these boards? i saw a youtube video from tubemictests (http://"https://www.youtube.com/watch?v=NRf68k6wDhg") where they tested a Flea vs Vintage and i think the Flea had the 6S6B and it definitely sounded close as hell, just a tad darker. very cool!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: trans4funks1 on April 27, 2017, 09:10:51 AM
Hi,
  Thanks for the information about the power supply.

 With other projects Dany has posted a schematic of his circuit which has helped me compare both the part labels and part values with the original circuits.

 In this instance, where I am sure to not use the original tube and will almost certainly swap it with a 5840 I am especially curious to understand what other components have been adjusted to make the system work well.

 Ideally I would look at Dany's schematic and compare each part for part label nomenclature and value.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: useme2305 on April 27, 2017, 02:47:37 PM
i second the request for a schematic of Dany's version. would be really helpful.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on April 27, 2017, 03:07:13 PM
Hope this helps,

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,
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: trans4funks1 on April 28, 2017, 09:36:22 AM
THANK YOU!  :)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: trans4funks1 on April 30, 2017, 04:15:49 PM
Hi Dany,
 I drew a schematic for the D-49c circuit, and would like to know if you think it looks correct. I will make any edits and replace it with a clean copy if you can take some time, look it over and make suggestions.

 I am wondering about the styroflex caps; C1 and C6, It seems like those are rated at 630vDC because that is value of the items you can supply.
 If someone wanted to use some other type of cap what is the minimum voltage rating for these two positions?

edit: I removed the schematic because it was never confirmed to be correct.

 Thank you.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on April 30, 2017, 05:20:54 PM
Transfunk - awesome work! What program did you use to generate this schematic?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: trans4funks1 on April 30, 2017, 07:29:10 PM
 Thanks. I draw by "hand" in Adobe Illustrator.

 Having all the info on a schematic helps me understand what is going on, and I enjoy making the drawings.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 01, 2017, 02:44:53 AM
Great work!  :D
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: useme2305 on May 01, 2017, 04:52:51 AM
great work trans! thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on May 01, 2017, 10:34:14 AM
Hi Dany,
 I drew a schematic for the D-49c circuit, and would like to know if you think it looks correct. I will make any edits and replace it with a clean copy if you can take some time, look it over and make suggestions.

 I am wondering about the styroflex caps; C1 and C6, It seems like those are rated at 630vDC because that is value of the items you can supply.
 If someone wanted to use some other type of cap what is the minimum voltage rating for these two positions?

(http://harmoniccycle.com/hc/images/sound/mic/D-49/D-49c.jpg)
 
 Thank you.

Hi Mike thanks For doing That ,
i will try to take some time to revise this nice drawing , lately i have been so swamped.
about the caps C6 should be minimum 2X plate voltage and the polarisation caps Pol X2 at least ,
i do supply really small package 630V indeed so there is no issue there ,
you are doing miracle with those drawing ,
Thanks a bunch ,
Best,
DAn, <


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: trans4funks1 on May 11, 2017, 11:13:36 AM
I want to work on the D-49B schematic as well as a depiction of the original M49, but before I move on I would like to learn if anyone has noticed any required edits or revisions.

If anyone can please double check the schematic I have drawn against the originals I will greatly appreciate it.

I have checked them myself by following all the connections on both Dany's and the original Neumann schematics, but would like a second pair of eyes to scrutinize the work before I remove the preliminary notice and prepare drawings of the other two versions.

Thanks very much! :-)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: adrian on May 12, 2017, 12:54:54 PM
hello,
does someone know how to wire the AMI Bv11r?
there are 4 wires : 1 yellow, 1 red, 1 grey and 1 violet and I don’t wich one is wich?
there isn't spec on their website so I'm a little bit confused :o
any idea?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Bonnie1 on May 14, 2017, 11:37:02 AM
Hello Adrian,
Inside lid of transformer box should be the data sheet.
Red + Violet = Pri
Yellow + Grey = Sec

Email Atelier Magnetics if you need further assistance. sa[email protected]
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: adrian on May 14, 2017, 01:26:15 PM
thanks a lot Bonnie! ;)
there wasn't data sheet in the box but thanks to you I can finish my project!

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Phrazemaster on May 14, 2017, 01:56:22 PM
The folks at TAB are the best!!!!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on May 15, 2017, 05:21:56 PM
His boards are for using a 5840 sub-mini tube. The 5840s use a 6.2V heater.

You'll blow your AC701 very quickly at anything over 4V on the heater.

The good news is that's easy to adjust the PSU. The bad news (for me) was I had a heck of a time setting the other voltages - not sure why. Dany told me I had a gremlin in the mic after he helped me troubleshoot, so I rebuilt it with a new board and got it working. You'll have to figure out how to wire the AC701 because Dany's instructions are for the 5840.

Do NOT wire up the AC701 and turn on the mic without  having first gotten your PSU heater voltage calibrated with a dummy load to 3.8 ~ 3.9V. If memory serves the dummy load was 40K but look through this thread and Dany already answered this one.

Good luck!

Mike

For the AC701 dummy load, use 40 ohms.  Heater is 4 v at 100 ma DC;  ohms law 4 v/0.1 A = 40 ohms.  A 2 watt resistor should be ample; the dissipation is 0.4 watt.  The attached should help.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: micaddict on May 16, 2017, 02:42:04 AM
Do not overheat.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: e.oelberg on July 02, 2017, 02:29:50 PM
someone is selling 65mm diameter  plexiglas  boards.  They are cheap and usefull for this build
http://www.ebay.de/itm/Acrylglas-Rund-4mm-10-100mm-Scheibe-Kreis-Zuschnitt-Plexiglas/192015813481?_trksid=p2481888.c100651.m4497&_trkparms=aid%3D777001%26algo%3DDISCO.FEED%26ao%3D1%26asc%3D20160801204525%26meid%3D688e7c908f324c31b9a8afe66631ae04%26pid%3D100651%26rk%3D1%26rkt%3D1%26&_trkparms=pageci%253Ad65888cb-5f53-11e7-b6df-74dbd180e37f%257Cparentrq%253A048cf93a15d0aa1a2c5022effffbe191%257Ciid%253A1 (http://www.ebay.de/itm/Acrylglas-Rund-4mm-10-100mm-Scheibe-Kreis-Zuschnitt-Plexiglas/192015813481?_trksid=p2481888.c100651.m4497&_trkparms=aid%3D777001%26algo%3DDISCO.FEED%26ao%3D1%26asc%3D20160801204525%26meid%3D688e7c908f324c31b9a8afe66631ae04%26pid%3D100651%26rk%3D1%26rkt%3D1%26&_trkparms=pageci%253Ad65888cb-5f53-11e7-b6df-74dbd180e37f%257Cparentrq%253A048cf93a15d0aa1a2c5022effffbe191%257Ciid%253A1)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: adrian on July 08, 2017, 11:14:48 AM
hi!
I'm a little bit confused... just need to be sure what is the good point to measure bias for the M49b?
between R6 R7      /     HG
or between R6 R7         /         H+   
  ????

thanks! ;)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on July 08, 2017, 10:19:06 PM
I am looking at a schematic of the Neumann M49 using the AC701 and fixed bias (grid bias obtained via resistance divider, taken from DC side of heater and cathode connection).   The heater voltage of the AC701 is 4 volts, the cathode is at 4 volts.  There are 200 k and 300 k resistors in series, and a 150 M resistor connected at the junction of these two resistors.  The other end of the 150 M resistor goes to the AC701 grid.  The fixed bias is -2.6 volts in this case (2/3 of -4 volts).  Do NOT attempt to measure bias at the high impedance tube grid.  Virtually NO current flows in the 150 M resistor, so the DC voltage on either side essentially is the same!  The clone mic probably contains a divider similar to this to bias the 5840 or similar tube.  Measure bias on the supply side of the 150 meg resistor... the bias will be the difference between the measurement at the resistor junction and the tube cathode.  The voltage should be negative with the plus end of the volt meter at the resistor junction, and the negative end of the voltmeter at the tube cathode.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: adrian on July 09, 2017, 08:30:41 AM
OK Thank you!
so if I understand correctly I can check it between
the jonction of R6-R7 and R5   and  K+ (the same as H+).

I use RCA tube.
I have 1,6v between (R6 R7 R5)  and K+ : that's OK!
 I replaced R10 with a pot and to obtain 45v at Anode and I need 270k !!! wich is very much regarding the BOM value (100k)

 If I understand correctly the calcul for the tube running :
118v (my PSU output) - 45v (at A) = 73v
but I= U/R  so 73/270 = 0,27mA    very far from the 0,73mA  ?????? I know I must be wrong somewhere!!!

here is a quote I used to try to understand what I am doing...

it will really be only if you put a AC701K in there that you will obtain those precise results,
this is why the self bias is a no brainer but the b is much more fun and learning, 
I have 100K plate resistor, 120 - 68 = 52V so this mean 52V drop trough 100K means 0.52ma,  U= RI
52V/100K = i in ma

here is an example,
B+ = 115V
Plate = 53V
Drop across 100k (plate resistor)
= 115-53 = 62V Voltage drop across 100k
that means the tube running at .62ma
We want about 45V on the plate to get to
the specified 0.7ma then
 
the best at this point is to replace temporarly the plate resistor with a pot lets say  250K and try to tweak both bias pot and plate resistor pot until you find the nearest condition , no one uses same tube and this is a related together and the 2 parameter are related, this is the best approach once you find the sweet spot for it you can replace the plate resistor whit with a 1/4 watt resistor ,
try that and keep me posted and let me know what the balance value you find or the nearest , what tube did you used, and make sure you try the mic first.

Let me know,
Best,
dAN,


Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Colorblind on July 14, 2017, 01:14:37 PM
Hi All,  I tought I would share this with everyone , this is a Raw Picture content pictorial of the Prototype I have built for Andriejus.
While Andriejus is Polishing the Last details ,

Tip #1 always keep the lead of the HZ bridging component so you can use them to make the bridging so no need of fancy jumper and so much easier , this is build needs to be built from the top and down , except for the headbasket and capsule mount, well this is how I do it  ;)

I am hoping you will appreciate it , this also applies to the General Build of this one ,

So here it is
https://io.groupdiy.com/file/gdiy-2017/u/39511/597b45d76f1cd.zip


Best,
Dan,

Is this pictorial the same as what is posted on page 1 of this thread, or something different?  The link doesn't work for me.

Thanks,

C
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on July 15, 2017, 03:21:00 PM
Getting "file not found" error message...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on July 15, 2017, 03:57:56 PM
OK Thank you!
so if I understand correctly I can check it between
the jonction of R6-R7 and R5   and  K+ (the same as H+).

I use RCA tube.
I have 1,6v between (R6 R7 R5)  and K+ : that's OK!
 I replaced R10 with a pot and to obtain 45v at Anode and I need 270k !!! wich is very much regarding the BOM value (100k)

 If I understand correctly the calcul for the tube running :
118v (my PSU output) - 45v (at A) = 73v
but I= U/R  so 73/270 = 0,27mA    very far from the 0,73mA  ?????? I know I must be wrong somewhere!!!

here is a quote I used to try to understand what I am doing...

Watch the DC plate current and voltage, drop the grid bias some to make the plate draw the desired plate current... for class A amplifier with constant plate supply voltage and plate resistor load, less grid bias voltage, tube draws more plate current and voltage at plate decreases....higher grid bias voltage, plate current goes down and voltage at plate increases.   I don't have the curves for the 5840 tube in triode connection in front of me, but my recollection is the grid voltage should run around -1 volt (measured at the resistor junction), and the plate voltage (measured at the plate) should fall in the 40 volt range, with  100k plate resistor to 120 v HT.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: adrian on July 25, 2017, 02:56:37 PM
ok!
thank you a lot for this explanation, I think I better understand how it works!
so the bias is to adjust the current, I don't really need to have at 1,6v exactly, It's the adjusting parameter.

 I go back to R10 at the initial 100k value.
I measured voltage at A and adjusted it to have 45V (120-45/100= 0,75mA).
so I'am in the good value regarding the curve .
I checked and I have -1,12 V between R6-R7 and K+

I built a second mic and to obtain 0,75mA I have -2V between R6-R7 and K+.

is this difference between these 2 mics OK? what is the correct margin of tolerance ?



Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on July 26, 2017, 12:35:06 AM
Mic 1:  Characteristics appear good.  Try recording anything with it?  Background noise level acceptable (low)?

Mic 2:  New tube?  Try a 48 hour burn in and recheck.  Try another tube.    Sylvania has curves for the 5840 in triode connection.  -2 v on the grid seems high. 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: poctop on July 30, 2017, 11:29:38 AM
Is this pictorial the same as what is posted on page 1 of this thread, or something different?  The link doesn't work for me.

Thanks,

C

hope this one will work ,
Best,
Dan,
https://www.dropbox.com/s/w9jqatxdi9p45wy/M49%20Build%20Pictorial.zip?dl=0
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Colorblind on July 31, 2017, 01:57:30 PM
Thanks Dan!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: TillM on October 14, 2017, 02:32:23 PM
I've a question about the PSU wiring.
I use the 186B20.
For 230v do i have to use pin 1 and 4 and solder pin 2 and 3 together to get 230v ?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Jim50hertz on October 15, 2017, 08:03:37 AM
If one is using 6s6b triode instead of the 5840 is this transformer able to cope with the extra current draw?
http://www.mouser.com/ProductDetail/Hammond-Manufacturing/186B20/?qs=sGAEpiMZZMvwUzoUXIIvyQPvPmwnNFGyR%2fQB%252b1BzrOY%3d
Title: Need some help with building the PSU out...
Post by: achase4u on December 17, 2017, 12:34:26 AM
Hello all.  I am grateful for this forum.  I need some direction.

I have built up my Poctop D49C to almost finished.  I am good at understanding thorough instruction type builds (Hairball 1176, CAPI BT50 etc) but less so with things like this that assume you have a little more knowledge to fill in the blanks.  I can read a basic schematic, but I am a little lost on my power supply currently as it relates to the choke/mains etc.  On the hardware side, I can build and that is all coming together quite well. 

Are there any instructional videos on basics I could watch, or articles/books that would help me in this area of power transformers?

I do realize the PSU can be deadly.

I am having trouble identifying which transformers are what on the PSU schematic on page one of this thread.  I also can't seem to identify a part of the PSU schematic that shows the IEC connection and switch connection etc.

If anyone feels like throwin' me some help, that would be cool.  I'd like to learn about this and do future projects.

I downloaded the toroidal data sheet so I see where the secondary goes to the PSU board, but I don't know where to wire the primary.  That's a start, I suppose.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on December 19, 2017, 10:35:54 PM
Look at the manufacturer sheet on the power transformer.   Assuming the power transformer is single primary voltage.  Usually, the primary leads are black.  Multi voltage primaries may involve paralleling windings (for US 120 volt) or series windings (for European 220-240 volt) use.  High voltage winding (HT AC to rectifier) leads are usually red, with center tap (if present) red/white.  Heater winding leads usually green; center tap (if present) green/white.  You may be able to verify this with a suitable ohm meter before connecting power.

You ARE right, the HT off the transformer OR off the PSU output (due to capacitors) can be deadly.  Work safe.  If you are testing with power, connect the meter first, then turn on the power.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: achase4u on December 19, 2017, 11:26:42 PM
That helped me understand.  I am missing some basic knowledge here and what I has assumed incorrectly was that one specific side of the primary had to be connected to neutral and the other to hot.  This transformer uses parallel windings and I can easily see on the data sheet which connect to one another for 120v.  So in this configuration, there is no phase reversal possibility from the primary to the secondary?

I indeed will work safe.  Nothing worth dying over here.

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on December 19, 2017, 11:40:44 PM
If the power transformer is split primary, follow the data sheet for paralleling the primary sections correctly.  This is important.  Hard to second guess the manufacturer on this one and get the phasing correct.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: achase4u on December 20, 2017, 12:14:15 AM
"Input1: Series – BLUE and BROWN, Jumper GRAY to VIOLET
Parallel – BLUE and BROWN, Jumper BLUE to VIOLET, GRAY to BROWN

Output1: Series – BLACK and YELLOW, Jumper RED to ORANGE
Parallel – BLACK and YELLOW, Jumper BLACK to ORANGE, RED to YELLOW"

So on the AC input, Blue and Violet together, and Gray and Brown together. 

On the output, Black and Orange together, and Red and Yellow together.

My question is, if I maintain the proper parallel wiring as in wire Blue and Violet to neutral, and Gray and Brown to Hot on my IEC, does this dictate which pair of secondaries goes to either spot on the PSU board?  Or is phase reversal at the PSU not possible?  I don't see reference to such a distinction on the PSU schematic pg1 one of this thread. 

Another way of saying it - does Blue and Violet on the primary side = Black and Orange on the secondary side?  Or does it = Red/Yellow, or neither?  I feel like there is a piece of basic information I don't understand here.  Since the voltage is only transferred via magnetism, does this direct relationship not exist?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on December 20, 2017, 12:25:47 AM
The data sheet makes sense.  This reads like paralleled windings on the primary.  As for the secondary, the voltage is rectified so the polarity of the AC on the rectifier input makes no difference as long as the rectifier itself is installed properly.  Some of those rectifier bridge assemblies have the AC inputs, and the + and - DC outputs marked or embossed on the case.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: achase4u on December 21, 2017, 12:27:17 AM
Thank you for clearing that up.  I can understand this transformer now.

I see on the PCB where I am to connect AC20v as well as AC120v, and they both go to a series of diodes on the PCB.

So the next thing is looking at the 20v transformer, I assume this is stepping down from 115v to 20v.  Shown here as 187b20 http://www.mouser.com/ds/2/177/186-187-948805.pdf

Looking at the lugs here https://www.hammfg.com/files/products/186-187/186-187bulletin.pdf in figure 7b, I see lugs 2/3 are the primary with lug 2 being the coil start of the primary.

On the secondary side, I see 5-7(7 is a center tap) is one coil, and 5-8 is both coils, with 5 being coil start.  I am not clear on which two lugs to wire on the secondary to get 20v here.  I've read both sheets and I can't seem to find a description like the toroid has.  I assume this is because I don't have the basic knowledge of reading a transformer schematic correctly.  Could you give me a hint on how I know which lugs to use on the secondary of the Hammond?

There is also the small issue of this Triad filter reactor as well.  I apologize for being uneducated here.  I am looking at the PSU schematic from page one and I don't see what is what here.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: TillM on December 31, 2017, 07:59:16 AM
After one week my M49 work flawless it stopped passed audio today :(
I was really shocked and went to trouble check.
I noticed, that H+ is still on 6,2v and K is 1,6V.
But now it comes.
B+ is hanging on 0,9v to 1,1v instead of 120v.
I biased my B+ trimmer to 119,8v.
What is happened ?
The Tube still burns and no capacitor in the PSU seams to be broken. No smoke and so one.
What could happened ?
Where I've to start my trouble check ?
Hope you guys can help me.

EDIT: Found the mistake. I burned my fuse. I just had to find out, why my fuse burned down
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: rmburrow on January 01, 2018, 02:49:02 AM
Need to figure out why the fuse blew... Unless there is a short or other problem, the fuse should not fail...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 59flame on February 02, 2018, 02:35:55 PM
i have a b version and i am confused on how to measure the 1.6v bias. i have 120 at pad5,  50v at r10.  h+=6.1v   k=6.1 v. is ther a place i can mesure the 1.6v in the b version?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 02, 2018, 04:20:10 PM
To bias 1.6V from grid to cathode measure across R6.

Is your R10 100k (like the schematic)?

Bias based on current to start. Here's how I'm re-biasing with my newly installed 6S6B:

-record a test clip
-clip one DVM lead to R7 on the power supply
-unscrew the mesh from the mic body
-mute input on DAW
-measure voltage at tube plate (was 64V after tube swap for me)
-adjust bias pot to see 73V (73 across 100k is 0.73mA)
-slide mesh back on without installing screws
-record test clip @ 0.73mA
-repeat steps above for 0.67mA, 0.68mA, 0.69mA, etc
-go to sleep and compare clips the next day

There will be some drop from the power supply to R10 but since I'm biasing by ear anyway it doesn't matter. At 0.7mA that drop is probably negligible anyway.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 59flame on February 02, 2018, 07:48:10 PM
yes i have 100k plate resistor. here are my voltages   6s6b tube  cinemag cm6511
b+ 120.5
r10 50v  120-50= .7 should be good i think
h+6.1v
bias 1.07v  this seems pretty  low  from the 1.6   this was measured at across r6. should i try to get this higher with a trimmer across r10 to get that closer? 
back plate polarization voltage between node r8 and r9    57.2v
I think from what i have read i may be close but wasn't sure if i need to try to tweak bias closer to 1.6v
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 02, 2018, 09:37:29 PM
R10 is your load. No need to adjust. Adjust your bias with a trim pot in R7. If you used Dany’s BOM you should have one there.

Don’t worry about the 1.6V or 0.73mA. Pick one for a starting point and adjust your bias by ear. If you have the equipment to inject a tone and measure THD you can bias faster and more accurately than by ear. I don’t so I do it by ear. I use my own voice even though I’m a terrible singer. I find it helps because I know it well.

Both 1.6V and 0.73mA are based on the AC701. To get the most out of your 6S6B you may have to change your bias, C4 and R10. Start with the bias, then C4 then R10. You may have to re-bias when changing components.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 59flame on February 02, 2018, 10:23:13 PM
the mic sounds good it does have lower out put then the u47. But sounds good. I also have a small hum but may need to burn in the tube.  not sure if that is where its coming from but i will burn it in for awhile and see if that helps. I will tweak r7 more  and try some of your suggestions and and record some clips with different bias settings and see where that takes me. 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 03, 2018, 11:36:41 AM
When adjusting your bias give it a moment to settle before measuring or remeasure before each re-adjustment. The bias may be easier (and safer) to adjust with a trim pot adjuster rather than a screw driver. If you don't have one, order it when you put together your next project cart. They're useful to have.

https://ca.mouser.com/ProductDetail/Bourns/H-90?qs=sGAEpiMZZMtC25l1F4XBU6Oesurqb%2f2Mwxsc%2f5lXeb4%3d (https://ca.mouser.com/ProductDetail/Bourns/H-90?qs=sGAEpiMZZMtC25l1F4XBU6Oesurqb%2f2Mwxsc%2f5lXeb4%3d)

Also, remember that the anode has enough potential to pop a fuse so be very careful poking leads in there while the mic is still in its body.

Shut down your power supply while listening to the mic and see if your hum immediately goes away with the power off. The tube is still hot and the caps have your 116V still up. If the hum immediately goes away it's probably your power supply.

I had trouble on this mic with hum. Lots of trouble. I used the same grounding scheme as my 251 and U67. I had even thought it was poor choke orientation since I crammed it into a small chassis. I bought a new Dandeurloo case, rebuilt it and had the same issue. I had tried other grounding  schemes (lifting shield from 0V in mic) with no success.

Finally I reterminated the shield to 0V inside the mic, ran the pin 3 (shield) to the PS PCB through a switch and lifted the 0V connection to ground inside the PCB - all based on mrerdat's scheme (like the Neumann schematics).

https://groupdiy.com/index.php?topic=50021.msg796487#msg796487 (https://groupdiy.com/index.php?topic=50021.msg796487#msg796487)

It fixed it. The PS chassis is grounded at the IEC plug. When the switch is open the PCB in the PS only receives ground reference via the mic (inside the mic 0V is tied to the shield).

I'm still not sure why only this mic had the problem but I'll be modifying my other power supplies to match.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 03, 2018, 01:29:39 PM
Also, M49 levels vs U47 levels. Are you comparing with your U47 in omni? U47 in cardioid will be 4dB or so louder because the back diaphragm is disconnected (no longer in parallel with the front). You can do the same on an M49 if you install a switch or relay.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 59flame on February 03, 2018, 07:56:00 PM
good info thanks  i'll check all this and see what i end up with. thanks for all your help! Scot
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 20, 2018, 06:46:17 AM
Hi all,
I would really appreciate your help with a strange problem with my m49b style mic.

So I read both threads and didn't find anything pointing me in the right direction...

When trying to bias the tube I tried to get around 60V at the anode and around 1.6 at  R6, the problem is that when I'm around those voltages the tube sounds as if it is switching on an off.
When I connected the mic to an oscilloscope it shows a sine wave when there is no signal at all.
Very strange.
When I turn R7 at both ends the sine wave disappeared slowly, but I'm getting 120V at anode and 4.7v at R6

What am I doing wrong? :o

Thanks
Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 20, 2018, 11:03:35 PM
Unless you're using an AC701 don't expect to meet both the bias voltage and current specified on the schematic. I used the idle current to bias because it's the easiest to track (73V across 100k = 0.73mA). My 6S6B is biased for 0.69mA (for now).

Your bias is roughly 0.60mA if your supply is 120V which is close enough to pass audio properly.

A sine wave with no input? I would guess 100Hz from your power supply. Can you check what the frequency is?

If your mic sounds as if it is switching on and off, I would suspect something is wrong with your wiring - possibly in the bias. If this is the case, it would be best to carefully look everything over without powering up your mic. Unless you mean the mic sounds as if it's switching on and off while you're measuring voltage. Don't measure at the tube grid like the schematic shows! Measure across R6.

As always with mics, make sure everything is clean - especially in the Hi-Z components!

https://groupdiy.com/index.php?topic=58771.0 (https://groupdiy.com/index.php?topic=58771.0)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 21, 2018, 05:54:21 AM
Unless you're using an AC701 don't expect to meet both the bias voltage and current specified on the schematic. I used the idle current to bias because it's the easiest to track (73V across 100k = 0.73mA). My 6S6B is biased for 0.69mA (for now).

Your bias is roughly 0.60mA if your supply is 120V which is close enough to pass audio properly.

A sine wave with no input? I would guess 100Hz from your power supply. Can you check what the frequency is?

If your mic sounds as if it is switching on and off, I would suspect something is wrong with your wiring - possibly in the bias. If this is the case, it would be best to carefully look everything over without powering up your mic. Unless you mean the mic sounds as if it's switching on and off while you're measuring voltage. Don't measure at the tube grid like the schematic shows! Measure across R6.

As always with mics, make sure everything is clean - especially in the Hi-Z components!

https://groupdiy.com/index.php?topic=58771.0 (https://groupdiy.com/index.php?topic=58771.0)

Hey thanks a lot for taking the time to answer!

The mic does switch on and off not while measuring voltage but during the bias process. I tried to bias by ear and then measure voltage.

Maybe my biasing process is not right?
My steps are as follows,
1. Set the heater Voltage to 6.2V with a 47ohm resistor.
2. Set the b+ voltage to ~120V.
3. Connect the mic and let the tube heat up for 20 minutes
4. Measure across R6.
5. Listen and adjust R7.

When I reach a normal biasing voltage the mic become unusable.

When you say "wrong with the wiring" in the bias what do you mean?

On a side note, I tried already two different tubes, one 5840w and one 6s6b.
Both have exactly the same symptoms.

Thanks again
Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 21, 2018, 10:13:28 AM
Check for shorts. Make sure the high impedance section is clean. I meant capsule bias, I should've been clear. If something is dirty or shorted anywhere that 120V supply goes, it could cause intermittent on/off sound.

I don't have anywhere near the experience as others here though. Maybe if you recorded a sample and posted here someone else would know where to look.

Check for shorts in in your cable too.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 22, 2018, 05:57:47 PM
Check for shorts. Make sure the high impedance section is clean. I meant capsule bias, I should've been clear. If something is dirty or shorted anywhere that 120V supply goes, it could cause intermittent on/off sound.

I don't have anywhere near the experience as others here though. Maybe if you recorded a sample and posted here someone else would know where to look.

Check for shorts in in your cable too.

(https://lh3.googleusercontent.com/n5XcWaAvJaYvOSyQqY_N9t1wW1E8TPb82nYsWe9NIMNtAvQmZ9AJLUdj8xAZxxeSPHjGivofy520J6i9syLUbC68jGNCl-8mO7pefnnX3Udj0ZbslIxITbZac-zQZ0nJrdxTP7yKDZF4cirUAB_AGgGfuLHgWBUOLUq3hX8JSuZ7rDt_G-tt3LWHGUsaSeoUN2b0nHogeCo6oJeIZodzyjshfftOz0RLsxWpvr0vODKFaS2Q_65NlKJsYObV9YPABT09vJKrroWTdVy3AbHpVkdB9GV_I9u4_CvcrDSUOpikPQf0XIeq1jVmoGZjMkg1wWWy45-mWqmASN0HIongRsoLhydAr3NAed_QA4KRSjQcFItyTr-XzU-OgHvLAePiV3TuuRFAu-78GzGGHXqMoPz_r6_iXwJ49WxFGYZjyY56DPgTUSs4XLOaDBKuGe8DKO8Qe73bTJ97BC-a_Y95wB2UCH8Cax46NEi4cSbReXg6gEIjjgVpLTfuy-Xf-l2lZ9PsRi4nEgW9wFdZRkeHOUuYF5tMX80qjkCWK_WuAeOv3bA8203DtqQvKkb-iCR1sggvxtdsKI9okuZUi6Q5nVoG5IJEl9j_tupn2_IW=w1040-h780-no)

Here is a picture of the noise I get. It's 2.4Hz.

The noise only goes away when I turn R7 in the mic fully anti clockwise. (which means full 2Mohm resistance?)
In this situation voltages are:
B+ =124V
H+ =6.1V
Across R10 = 6V
plate =117V
across R6 = 5.99

I also cleande the capsule bias section again using IPA 99%.
It didn't solve the problem.

Cheers
Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 22, 2018, 06:09:49 PM
The picture didn't load for me. 2.4Hz is odd; can't say I have any ideas on where to go but I would avoid biasing so far off and troubleshoot with the bias set close to where it should be.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 22, 2018, 06:24:25 PM
The picture didn't load for me. 2.4Hz is odd; can't say I have any ideas on where to go but I would avoid biasing so far off and troubleshoot with the bias set close to where it should be.

I'll try the picture again.

(https://preview.ibb.co/eZrThc/IMG_20180222_234538.jpg) (https://ibb.co/joUENc)

I think I'll heed your advice, I now just let the mic run for a day or so to see if maybe it has something to do with the tube.

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 23, 2018, 05:31:13 AM
So after burning in the tube all night, now the frequency of this strange noise is 1.6Hz.
I can't get my head around why it's there in the first place.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 23, 2018, 10:26:08 AM
Is audio still cutting in and out? What rate is it doing it at? Does it match the frequency your oscilloscope sees? Can you monitor your B+ at the power supply and see if it is changing (dropping) when audio cuts out?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 24, 2018, 04:00:26 PM
Is audio still cutting in and out? What rate is it doing it at? Does it match the frequency your oscilloscope sees? Can you monitor your B+ at the power supply and see if it is changing (dropping) when audio cuts out?

Hey Delta, I am extremely greateful for your tips!

So after listening in to the audio it seems that it doesn't cut out, rather as if it changes phase in time with the frequency I'm seeing at the oscilloscope.
I'll try to record a bit where you can hear it.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 25, 2018, 01:21:15 PM
Some more tests, when switching patterns, at first this wave doesn't occur but after even a little noise in the room it starts to amplify itself, as if it is some sort of bad feedback, again just changing phase at a rate of now 2.2Hz.

I tried to remove C4 but the feedback persists. 

Which part of the circuit would cause such behavior? ???

I'm totally puzzled by this. :o

Best
Moshe
 
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on February 25, 2018, 05:42:35 PM
Hello Moshe,

i didn't read all your posts, so if you already tested mentioned below parts of the circuit, then just skip it:)
I'm not sure which tube you are using for your build.

- try it with "true cardioid" only - if you used S2 for that purpose, then use it and just setup pattern selector to omni
Otherwise disconnect C1 from the front capsule side and set pattern switch also to omni

- try to change capsule for any other and observe is there the same behavior or swap the capsules sides if you don't have any spare

- check C1 at the first place in case of passive components

- for different substitute tubes there's worth to test C4 values from 3.3pF-10pF range

- if anything from above list didn't help, then disconnect R3 from C5 as also C2 from R2 - then test again
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 25, 2018, 06:28:08 PM
Hey In76d!
I really appreciate you chiming in.

Hello Moshe,

i didn't read all your posts, so if you already tested mentioned below parts of the circuit, then just skip it:)
I'm not sure which tube you are using for your build.
I'm using 5840W, but also tried 6s6b-V.

Quote
- try it with "true cardioid" only - if you used S2 for that purpose, then use it and just setup pattern selector to omni
Otherwise disconnect C1 from the front capsule side and set pattern switch also to omni
I did disconnect C1 from the capsule side, but didn't set the selector to Omni, so I probably need to try that again. When I disconnected C1 I had less off that strange waveform.

Quote
- try to change capsule for any other and observe is there the same behavior or swap the capsules sides if you don't have any spare
I don't have a spare capsule at this moment, but I put two 51pf caps instead of capsule for testing, to the same effect.

Quote
- check C1 at the first place in case of passive components
I didn't understand what you mean by that. Anyway I swapped out C1 to another cap I had lying around.

Quote
- for different substitute tubes there's worth to test C4 values from 3.3pF-10pF range
When I put a 10pf cap in series with the 8pf the problem got worse, when I put it in parallel it got a bit better. 

Quote
- if anything from above list didn't help, then disconnect R3 from C5 as also C2 from R2 - then test again
I will try that if it comes to that.

Thanks a lot!
Now I have something to do ;)

Best Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on February 25, 2018, 06:58:30 PM
Hey In76d!
I really appreciate you chiming in.
I'm using 5840W, but also tried 6s6b-V.
I did disconnect C1 from the capsule side, but didn't set the selector to Omni, so I probably need to try that again. When I disconnected C1 I had less off that strange waveform.
I don't have a spare capsule at this moment, but I put two 51pf caps instead of capsule for testing, to the same effect.
I didn't understand what you mean by that. Anyway I swapped out C1 to another cap I had lying around.
When I put a 10pf cap in series with the 8pf the problem got worse, when I put it in parallel it got a bit better. 
I will try that if it comes to that.

Thanks a lot!
Now I have something to do ;)

Best Moshe

Why you resigned from 6S6B?
Selector to omni is just to prevent  applying voltage to the back diaphragm.
What kind of capacitor and what's it voltage rate -  for C1?
Great - i forgot to write about replacing capsule with capacitor and testing - if the behavior is the same then, i think we can exclude the capsule - last question about it - are the diaphragms clean? ;)
10pF and 8pF in series are ca. 4.5pF, paralleli 18pF (exluding capacitors tolerance here).
With lower value, you will get more gain so the "side effect" is just boosted and opposite with higher value.
What's voltage rating for your C4? If these are typicall ceramic capacitors with 50V ratings then maybe try some different with higher voltage rating.
I didn't had such issues with 5840, but some folks here had issues with oscilations using solid state replacements.
From what i remember it wasn't proper substitute to work with feedback which provides fixed HPF.
It's mentioned earlier whole node which starting from R3.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 25, 2018, 07:19:27 PM
Why you resigned from 6S6B?
I didn't, just tried different tubes to see if the problem goes away.

Quote
Selector to omni is just to prevent  applying voltage to the back diaphragm.
What kind of capacitor and what's it voltage rate -  for C1?
Polystyrene, 1000pf 600V, I thought at first that maybe I damaged it so I replaced it with polystyrene 250V that I had.
 
Quote
Great - i forgot to write about replacing capsule with capacitor and testing - if the behavior is the same then, i think we can exclude the capsule - last question about it - are the diaphragms clean? ;)
Yes, capsule is brand new Thiersch red line.
 
Quote
10pF and 8pF in series are ca. 4.5pF, paralleli 18pF (exluding capacitors tolerance here).
With lower value, you will get more gain so the "side effect" is just boosted and opposite with higher value.
OK, so that explains what I found.
 
Quote
What's voltage rating for your C4? If these are typicall ceramic capacitors with 50V ratings then maybe try some different with higher voltage rating.
C4 is silver mica (first 8pf, now 18pf) rated 300V, would you recommend switching to ceramic cap?
 
Quote
I didn't had such issues with 5840, but some folks here had issues with oscilations using solid state replacements.
From what i remember it wasn't proper substitute to work with feedback which provides fixed HPF.
It's mentioned earlier whole node which starting from R3.

Ok i will search for it and read up.

Thanks a million!

Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on February 25, 2018, 07:26:06 PM
I didn't, just tried different tubes to see if the problem goes away.

Polystyrene, 1000pf 600V, I thought at first that maybe I damaged it so I replaced it with polystyrene 250V that I had.

 Yes, capsule is brand new Thiersch red line.
 
OK, so that explains what I found.

 C4 is silver mica (first 8pf, now 18pf) rated 300V, would you recommend switching to ceramic cap?
 
Ok i will search for it and read up.

Thanks a million!

Moshe

250V-600V are ultra fine here - polystyrene are fragile for heat during soldering and cleaning with alcohol.
So the capsule is definately fine ;)
You can try different type of capacitor - silver mica voltage ratinge is totally great, but urban legends says that these can be microphonic - maybe this is your extra sound source? ;)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 26, 2018, 12:49:34 AM
Super happy for you that ln76d has chimed in. I definitely feel too inexperienced to be giving you advice.

I like the idea of changing the capacitor type for troubleshooting. Don't worry about your end result, just find your problem. If you throw in a cap you have you're not happy with (correct value and voltage rating of course) but your problem goes away you can always reorder a polystyrene or C0G/NP0.

I once suspected a polystyrene cap (wasn't the cap) so I placed a Mouser order for replacement C0G/NP0 caps. Some people say polystyrene caps can be microphonic. I've never noticed this but I do like the peace of mind in troubleshooting with less sensitive (to IPA and heat) caps. When I ordered the few caps I needed I went to Dany's site and viewed all of his projects to order values that I may need in the future.

The side benefit of replacing components is the rewiring job you're giving your mic could end up fixing the problem.

Also, please re-confirm your DC voltages are fine (correct drop across R10, R6 & R7) and are not fluctuating with the phase issue. If replacing the capsule with fixed caps leave the problem still audible this narrows your issue down quite a bit. C2, C3, C4 (C4 can be removed), R5 and R3 (R3 can be removed).

This is frustrating stuff but you can learn a lot here, especially with this circuit. This may be one of the best circuits for hobbyists to modify and experiment with.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 27, 2018, 06:31:54 PM
Thank you Delta and IN76d.

I removed R3 and the problem is gone. ;D ;D
If I understood right it has a function of a HPF? Does R3 act in conjunction with C3 as an EQ?

I checked all voltages again, voltage drop across R10 is 68V, seems in the right direction.
Did some short tests on my voice and it sounds really good.

Actually I didn't find it frustrating, I liked the learning experience.
Most of the build it was a lot

Now I can try the Aluminium Oil output cap that I have here ;)

I think I will try also to change C4 to 2-4pf C0G/NP0.

Cheers
Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on February 27, 2018, 06:51:44 PM
Hello Moshe,

great that you found the problem ;)

Yes, it's fixed HPF implemented to feedback circuit.
You should also get higher output. Without feedback it is similar to M49B/3 revision.
http://repforums.prosoundweb.com/index.php?action=dlattach;topic=37067.0;attach=2643;image
As you can see on schematic plate resistor is twice higher 200kohm - without feedback with this value you should get similar output level to the real M49, if we assume that with substitute tube it's correct.

If you don't want to use that feedback at all - then you can remove R3, C3, R4, R12, C8 and connect C2 direct to ground.
It will also remove measurement input, but i think it is useless for your needs.

For the grid-plate feedback try mentioned earlier range of capacitance. Don't let trick yourself with higher output, it usual can give impression of better response - rather do more tests and find the best sound for your needs ;)

Alu-oil? can be good - my first choice for the output always is paper cap, second a good MKT.
Try 0.5uF-1uF range if you like testing. You can be surprised with lower values, but all depends, if your mike with 5840 and bias schematic values have lower low end, then rather go to 1uF.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 27, 2018, 08:22:26 PM
I removed R3 and the problem is gone. ;D ;D

Awesome!!! It's quite a good feeling when you finally nail a circuit you've been struggling with.

If you have a few minutes, can you review your posts and edit them so both the original symptom is bolded and the solution to the problem. It makes it easy for those troubleshooting a similar problem to see your problem and solution.

I wonder if there was a problem with your 5M resistor or if maybe it has some oils from handling. Did you wear gloves? Next Mouser order, you should pick up another 5M resistor, maybe even a something bigger (for less feedback). You may not like the mic better with R3 back in but it's good to know.

Same with C4. Don't rip it out and be happy with no C4 vs C4 of 8pF. Try a few different values and record your results. I ended up deciding on 2pF then eventually removing it altogether. C6 is a low pass filter that can be reduced in value or removed. Many people remove C6 but I have mine in for now.

This is a very fun circuit to play with!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on February 28, 2018, 04:56:32 AM
Thanks!

I edited the posts, good idea.

In76d, do you think I should switch the plate resistor to 200k? Now I'm getting voltage drop of around 68v witch should be ok, or did I get that wrong.
Anyway it sounds pretty good.

I think I'm gonna try to put a 15MOhm resistor I have in place of R3.



I wonder if there was a problem with your 5M resistor or if maybe it has some oils from handling. Did you wear gloves? Next Mouser order, you should pick up another 5M resistor, maybe even a something bigger (for less feedback). You may not like the mic better with R3 back in but it's good to know.

Same with C4. Don't rip it out and be happy with no C4 vs C4 of 8pF. Try a few different values and record your results. I ended up deciding on 2pF then eventually removing it altogether. C6 is a low pass filter that can be reduced in value or removed. Many people remove C6 but I have mine in for now.

This is a very fun circuit to play with!

I do wear nitrile gloves when I work on mics. I don't think that the resistor was faulty, I measured it after I removed it.

For now I left C4 8pf.

Again thanks a million!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 28, 2018, 10:32:41 AM
In76d, do you think I should switch the plate resistor to 200k? Now I'm getting voltage drop of around 68v witch should be ok, or did I get that wrong.

Just in case ln76d doesn't chime in, 68V gives you 0.68mA. The Neumann schematics (M49b) show 0.73mA. Not only are you close to the schematic but you're very close to the 0.69mA that my M49b with 6S6B is biased at right now.

I believe the M49 version that used 200k had a different transformer which made a 200k load resistor make sense.

I am curious if ln76d has thoughts about a different load for the 6S6B or 5840. There are ways to keep the amp biased the same and change the load sort of like in a U47.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on February 28, 2018, 11:02:28 AM
Just in case ln76d doesn't chime in, 68V gives you 0.68mA. The Neumann schematics (M49b) show 0.73mA. Not only are you close to the schematic but you're very close to the 0.69mA that my M49b with 6S6B is biased at right now.

I believe the M49 version that used 200k had a different transformer which made a 200k load resistor make sense.

I am curious if ln76d has thoughts about a different load for the 6S6B or 5840. There are ways to keep the amp biased the same and change the load sort of like in a U47.

Yes, but this is voltage and current reading, did you tried to trace both tube characteristics to compare operation points?
Not without a reason 5840 in exact M49C circuit have low end rollof  (without feedback HPF aplying).
If you change the bias (voltage and current), which change the point, then you will get flat response in low end, but it will change output level etc.
Except AC761, rather there's no other tube which fit exactly AC701 specs.
Even Oliver made for this occasion a version of T49 with "extended"low end.
I can't speak for M49B/3 transformer, since i didn't had it in my hands.
You can change the operation point in both ways - changing plate resistance and changing biasing resistance.
Best way is to mix both options and tune it for the needs.
Of course change of plate resistance will change output impedance but are you sure that 5840 or 6s6b will give you 200ohm output?
There were different transformers from what i have found. Even for BV11 some sources stand for  10:1 ratio, like some of transformer equivalents,  but IRT schematic shows 7:1.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Delta Sigma on February 28, 2018, 11:41:57 PM
I used Oliver's BV11r (extended low end and low mid) in my build. After replacing a 5840 with a 6S6B and getting a fuller low end I wondered if I made a mistake buying the BV11r. Interestingly, though, the AMI transformers page lists the BV11a for AC701 and the BV11r for 5840 but I found this on the TLM49 conversion page:

Quote
For my AC701 build I used the AMI BV11a (the very early transformer original used for the MSC2 tube) and for the 5840 I used the AMI BV11R (the one that was used for the C version).

http://www.tab-funkenwerk.com/id84.html (http://www.tab-funkenwerk.com/id84.html)
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on March 01, 2018, 06:37:52 AM
Hard to guess what Oliver (R.I.P) had in mind and what were his sources of knowledge for the original transformers. He often wrote about Braunbuch.  Anyway this text from the link can be understood in double way.
There's probability that original BV11 of M49C had higher ratio. If you will look for  B and C datasheets, sensitivity of B is 7mV/Pa and the C is 6mv/Pa. I'm not sure which B version this datasheet is. If standard B, then both should be 8pF plate to grid feedback.
With the same ratio transformer C should be higher sensitivity than B. Of course still there's question about the output impedance of both!?!?
Still AMI BV11 standard also is 10:1 and it datasheet for the source shows exactly Braunbuch mentioned earlier :)
It's funny because i had both in my hands (never at the same time) but at the time i didn't even think about ratio measurement, it wasn't any point of the work, at the time i even didn't think that for few years i will start to build these circuits :D :D :D
Anyone can borrow time maschine?? Tardis will be enough i think - anyone have number to that new Dr. Who? 
Title: Re: D-M49 Build Thread Puck Style ( TLM49 Conversion To M49 b-c ? )
Post by: r2d2 on March 01, 2018, 12:01:51 PM
Neumann M49 is around ten thousand dollars these days. A TLM49 conversion at a fraction of the price sounds like a great deal for essentially the same mic.

Does anyone know of any similarly sized/shaped donor bodies for the D-M49 (hopefully cheaper than a Neumann)?

-James-

just "as well"  , it must be said that:

The sound of the original U47 come from  the VF14 (Helmet) original Tube ,
many have tried various different types of tube as replacement,
but no success about ,
and beware : there are many VF14 Fakes for sale , overall online…..
some info about here (as well):
http://www.phaedrus-audio.com/VF14M_story.htm

Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: lkipod on March 03, 2018, 06:26:33 PM
Wow Delta and In76d, loving these posts...
It just takes me time to understand them ::)
That's the reason why I got hooked up with microphones, every detail is a whole world of knowledge... One day I'll understand ;)

In another thread (about negative feedback) there was mentioned that the Phaedrus tube had this 3Hz oscillation that I experienced. Someone said there that it is because the electronic tube has a 180° phase shift at 10 Hz. If that's so why did it also occur to me with 6s6b-V and 5840 tubes? That doesn't make sense to me.
Or could it be that the tubes experience the same sort of phase shift? (Not very likely?..)
For me the problem is gone but it still intrigues me.

Best
Moshe
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on March 03, 2018, 06:44:10 PM
I didn't investigated the feedback issues, because never had any problem with it.
Hard to say - maybe the reason is elswhere than mentioned in the other thread.
Also i don't know what sit inside the silicon replacement - so hard even to compare.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 4earstudios on March 11, 2018, 09:35:43 AM
Hello, great insight , a read through the forum and have two questions just to clarify : the construction we see here ist the C version? and 2. i do have a ac701 tube and want to built it with that - all i need ist to set the right voltage in the PSU ? beside that everything has to be built like in the instructions or am i missing smthg... thanks Daniel
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 4earstudios on March 22, 2018, 05:14:20 AM
Hello me again, wondering about the floating scheme, building version c, do i have to make connection from point to point as seen on the floating diagram...or is it made with the connection of the components as seen in the pictures of the built...thx Daniel
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: ln76d on March 22, 2018, 08:29:57 AM
Danny  boards will let you build both B and C version.
4V for AC701 heater.
Don't understand your next questions.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: 4earstudios on March 23, 2018, 03:05:39 PM
Thx for your answer on the second picture on site 1 : Floating Scheme connection For C version - there are white lines between some solder points - do i have to connect them? sorry for being so noobish - i usually build gear with step by step instructions...
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: thekim1 on April 04, 2018, 03:27:25 PM
Hi,
I got a problem with my m49c build.
After putting everything together i got the mic working for about an hour, then there was a loud noise in the audio input on the soundcard as the fuse broke on the m49 psu. After changing the fuse i cant get the mic to pick up audio.
Took a look inside both the psu and mic but could not se anything that had broke, the 5840 tube is still glowing when the psu is turned on.

This is the readings i got inside the mic with the pattern set to cardioid:
K: 3.74v
A: 6.35v
H+: 5.98v
FGRID: 4.18v
4: 5.95v
5: 119v
6: 55.2v
R8-R9: 40.0v


EDIT:
Found the problem, broken tube. Now everything is showing the right voltages and the mic sounds fantastic!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: kpearsall on April 21, 2018, 11:52:42 PM
Is anyone else using a 6.3v pilot lamp? How are you wiring it? Seems obvious to run it off the heater if the PSU will handle it. However, if the mic cable isn't properly connected, unloaded you'll send maybe 24v to the bulb. It's a number 47 1 watt bulb, so should I just throw a 1 watt 625 ohm or so resistor in series or just buy extra bulbs in case I do something stupid. Is there a best practice that anyone uses to do this in a better way?

Thanks!
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: captainate on May 18, 2018, 05:47:36 PM
Thx for your answer on the second picture on site 1 : Floating Scheme connection For C version - there are white lines between some solder points - do i have to connect them? sorry for being so noobish - i usually build gear with step by step instructions...

Hopefully you've figured this out by now, but the answer is no... there are traces under the PCB that would connect these points if you were not using the floating scheme, but since you are connecting them directly to the turret pin it is unnecessary to do anything else.
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: captainate on May 18, 2018, 05:53:04 PM
At the risk of opening a can of worms, are there any justifiable reasons to use a tantalum cap over an electrolytic cap in C9? It is very difficult to research the subject as people seem to have emotional reactions regarding audio capacitors.  Since one is risking a dead short if the cap fails, what supposed benefits does one receive in return?
Title: Re: Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)
Post by: Colorblind on August 08, 2018, 01:53:51 PM
Does anyone have any experience in modding the TPS100 style PSU for this microphone? What are the necessary mods?

Thanks!

I would also like to know this.   I built Dany & Oliver's D-EF47, and I found the PSU wiring diagrams a bit more newb-friendly than what's available for the D49.