Neumann U67 Clone : D-U67 Tube Microphone Build Thread.

[poctop]

Hi everybody, thanx for this wonderful thread, I ve just finished my mic with tskguy's capsule & AMI T67 transformer, sounds great!
Just to say that 11mm 0.01µ caps weren't available on Mouser http://fr.mouser.com/Search/ProductDetail.aspx?R=MKT1813310404virtualkey61310000virtualkey75-MKT1813310404 but I did it with thoose 16.5mm http://fr.mouser.com/Search/ProductDetail.aspx?R=150103J400BBvirtualkey53900000virtualkey539-150103J400BB
It fits Chunger's body without any problem!

Glad you made it 
Thanks for the tips,  I am glad it works out fine with the 16.5mm  lenght in this build ,  sometimes mouser is out of stock for a while or the minimum quantity is from another planet wich is annoying. but this is a great replacement Thanks to St-Gillis

but I did it with thoose 16.5mm
http://fr.mouser.com/Search/ProductDetail.aspx?R=150103J400BBvirtualkey53900000virtualkey539-150103J400BB

Best,
D.

 

[poctop]

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=Ntkrimary|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

 

[0dbfs]

Thanks Dan! I ordered 3x TFK EF800's and 4x Valvo EF86's for test/swap/spares in two of these mic's..

Cheers,
jb

 

[dgoszillai]

Hi,

i'm wiring the mic and i would like to know what is the best cables to use inside for switchs capsule and tranny.
i don't have the exact english word but you know you can use cable with one single "connector" ("brin" in french) that is stronger but harder to store inside the mic i guess. and other cables that are with lots of "connectors" ("multibrin" in french) that are easier to bend but maybe not that great (?)

and also maybe with heat one is better than the other ?

 

[HellfireStudios]

Hi,

i'm wiring the mic and i would like to know what is the best cables to use inside for switchs capsule and tranny.
i don't have the exact english word but you know you can use cable with one single "connector" ("brin" in french) that is stronger but harder to store inside the mic i guess. and other cables that are with lots of "connectors" ("multibrin" in french) that are easier to bend but maybe not that great (?)

and also maybe with heat one is better than the other ?

Solid core refers to one piece of wire. Stranded wire is made with multiple "strands" within the same insulation. Stranded has better flexability. Both wires can do the job well.

As for the heating aspect, PTFE insulated wire won't melt when it is soldered.

-James-

 

[dgoszillai]

hi thx for all the explanation !

 

[0dbfs]

I have been using stranded cat5 conductors in my builds without issue and in cases where I build my own cable I use conductors from that cable since they are good enough for a 20-30ft run they should be good enough for a couple more inches inside the mic.. CAT5 is small, flexible, multicolored and cheap. I wouldn't recommend using solid core hookup cable since it's somewhat more fragile than stranded but others may have different ideas too.

One of these days i'll get some spools of silver stranded ptfe hookup cable.

Ceers,
j

 

[Winetree]

One of these days i'll get some spools of silver stranded ptfe hookup cable.

Just ordered over 850 ft. of PTFE Silver plated stranded copper wire from Apexjr Wire (818) 248-0416
Best price I could find

 

[poctop]

One of these days i'll get some spools of silver stranded ptfe hookup cable.

Just ordered over 850 ft. of PTFE Silver plated stranded copper wire from Apexjr Wire (818) 248-0416
Best price I could find

should I be getting more boards now  ;D,
I bet you will be good for a While
Best
Dan,

 

[dgoszillai]

ok stupid question #2
what is the good position to put the AMIt67 on it's "AMII adapt bopad by DanB" i don't see where is the "reading" ont the transformer that inform about the side (or i miss something )

 

[poctop]

ok stupid question #2
what is the good position to put the AMIt67 on it's "AMII adapt bopad by DanB" i don't see where is the "reading" ont the transformer that inform about the side (or i miss something )

From the build thread page 1  you should be finding some black marking on your transformer somehow.

hope this helps,
D

 

[dgoszillai]

Oh yeah thanks i got that picture from page 1 + updates but i didn't see that "black mark" now i  got it !
so i have to put black mark from trans on the "="sign of the PCB.

 

[poctop]

Oh yeah thanks i got that picture from page 1 + updates but i didn't see that "black mark" now i  got it !
so i have to put black mark from trans on the "="sign of the PCB.

correct,
dan,

 

[poctop]

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,

 

[Floti]

Where are you guys getting bodies to do this build?

 

[HellfireStudios]

Where are you guys getting bodies to do this build?

http://store.studio939.com/product/syt-5-microphone-body-kit

-James-

 

[Joekkel]

hi everybody,

so i finished my build but i'm having some issues. as i plugged the mic to my powersupply, the voltage of B+ dropped to 170V and i had to remove the 56k-resistor in front of the 25k-poti to reach 210V loaded.

H- measures -6.3V, B+ 210V, and a measures 3.3V on the mic-pcb

i don't get any sound from the capsule, only thing i hear are microphonics when touching the mic-body. in the attached pic you can see C9 got touched by the solder-iron. could it be busted?

picture here: http://www.facebook.com/photo.php?fbid=10201190980723419&l=d155cfe515

other strange thing: the H- Pad on the mic-pcb is connected to ground, but only if the tube is in its place. is this normal?

i hear pops, when switching pattern/pad/l-cut. any help would be appreciated, thanks!

 

[poctop]

hi everybody,

so i finished my build but i'm having some issues. as i plugged the mic to my powersupply, the voltage of B+ dropped to 170V and i had to remove the 56k-resistor in front of the 25k-poti to reach 210V loaded.

H- measures -6.3V, B+ 210V, and a measures 3.3V on the mic-pcb

i don't get any sound from the capsule, only thing i hear are microphonics when touching the mic-body. in the attached pic you can see C9 got touched by the solder-iron. could it be busted?

picture here: http://www.facebook.com/photo.php?fbid=10201190980723419&l=d155cfe515

other strange thing: the H- Pad on the mic-pcb is connected to ground, but only if the tube is in its place. is this normal?

i hear pops, when switching pattern/pad/l-cut. any help would be appreciated, thanks!

this looks like a cold solder to me , but may be part of the problem as well.

H- measures -6.3V, B+ 210V, and a measures 3.3V on the mic-pcb

 

what does measure 3.3V on the pcb the B+ ? if it is B+ then somthing is not happening up to your mic pcb. check the B+ connection and wiring,

other strange thing: the H- Pad on the mic-pcb is connected to ground, but only if the tube is in its place. is this normal?

you might be confusing this little resistance for a short it should read something like 10ohm IIRC


it would seems that your tube or something in the circuit is drawing way too much current for your tube ,  what is the plate voltage you get on the (a) pad on your pcb , 

remove the tube and capsule and try to achieve proper bias voltage first , check for short or cold solder,

 

[Floti]

Where are you guys getting bodies to do this build?

http://store.studio939.com/product/syt-5-microphone-body-kit

-James-

Yeah, but it's been sold out forever!! I tried contacting Shuaiyin but they won't sell me in small quantity...

 

[poctop]

Where are you guys getting bodies to do this build?

http://store.studio939.com/product/syt-5-microphone-body-kit

-James-

Yeah, but it's been sold out forever!! I tried contacting Shuaiyin but they won't sell me in small quantity...

Chunger is expecting a load of them pretty Soon I beleive,
Best,
Dan,