MKH 416 T - phantom power mod.

[Spino]

I've come across a couple of used 416 T that would be a bargain. In the bargain it's included the little barrel that converts the phantom from the desk to the Tonesderspeisung 12V needed for the "T". (for those that don't know and are curious, T power is 12V across pin 2 and 3 whereas phantom would be usually 48V on pin 2 and 3 across pin 1)

I do know though that a bunch of people modified the T to make it work as a P48, and I was looking for infos on it.
In this very forum I found this schematic (http://www.uneeda-audio.com/phantom/p48t122.jpg), which seems quite simple and I guess it would be what's in the barrel. I find it hard to believe you can put this components inside the body of a 416, so I wonder if anybody has infos on how you can mod the mic to make it compatible.

Thank you in advance.

 

[mrclunk]

There’s a guy on ebay that sells little smt 48v to T-power boards that fit inside the barrel. I’ve used loads. Work fine, bit of a game to fit them inside.

 

[Spino]

There’s a guy on ebay that sells little smt 48v to T-power boards that fit inside the barrel. I’ve used loads. Work fine, bit of a game to fit them inside.

Thanks a lot for the infos.
After a few searches I found their facebook, their website and their shops, both on ebay and on reverb, but they seem to be out of everything unfortunately.

 

[mrclunk]

Here's the circuit. Next time i do some pcbs i'll make a bunch, could be a while tho.. I'd like boards that solder direct to xlr pins.

 

[RuudNL]

I have seen a similar schematic, but without the 1 mH coil. What is the function of this coil?

 

[Spino]

These are very close to the schematics I posted above. Now, the two 416 T that were a bargain were sold overnight to somebody else, how sad.
Anyhow, I have seen on google the pictures of the smd mini boards, but when I looked on Mouser for 68uF 50V or 60V caps, the smallest they have are some 10mm x 9mm smd electrolytics (or tantalums, but at 100$ each...) . I wonder what caps the original guy put on those tiny boards because they didn't look electrolytics and seemed a lot smaller than that.

Maybe another decent way of doing this is to make an xlr cable with the few components in the xlr shells.

 

[Grim Reaper]

Here's the circuit. Next time i do some pcbs i'll make a bunch, could be a while tho.. I'd like boards that solder direct to xlr pins.

Have you made any pcbs?

 

[Grim Reaper]

These are very close to the schematics I posted above. Now, the two 416 T that were a bargain were sold overnight to somebody else, how sad.
Anyhow, I have seen on google the pictures of the smd mini boards, but when I looked on Mouser for 68uF 50V or 60V caps, the smallest they have are some 10mm x 9mm smd electrolytics (or tantalums, but at 100$ each...) . I wonder what caps the original guy put on those tiny boards because they didn't look electrolytics and seemed a lot smaller than that.

Maybe another decent way of doing this is to make an xlr cable with the few components in the xlr shells.

Did you buy MKH416T mikes? I have a virtually mint matched pair of MKH416T-F for sale.

 

[Grim Reaper]

Here's the circuit. Next time i do some pcbs i'll make a bunch, could be a while tho.. I'd like boards that solder direct to xlr pins.

Have you made any? I want some to convert MKH416T to P48.

 

[mrclunk]

Have you made any? I want some to convert MKH416T to P48.

Ive ordered some proto boards. On the slow boat from china, about 3weeks.

 

[Grim Reaper]

Ive ordered some proto boards. On the slow boat from china, about 3wer hen you have the available fo

Let me know when they are available for purchase.

 

[classic86]

I built a couple of converters earlier this year, based on the circuit Ruud shared above. It fits into a Neutrik NA housing, if you don‘t want to wait for PCBs this is probably the fastest option.

 

[MichelN]

I've come across a couple of used 416 T that would be a bargain. In the bargain it's included the little barrel that converts the phantom from the desk to the Tonesderspeisung 12V needed for the "T". (for those that don't know and are curious, T power is 12V across pin 2 and 3 whereas phantom would be usually 48V on pin 2 and 3 across pin 1)

I do know though that a bunch of people modified the T to make it work as a P48, and I was looking for infos on it.
In this very forum I found this schematic (http://www.uneeda-audio.com/phantom/p48t122.jpg), which seems quite simple and I guess it would be what's in the barrel. I find it hard to believe you can put this components inside the body of a 416, so I wonder if anybody has infos on how you can mod the mic to make it compatible.

Thank you in advance.

The simplist way to achieve this is described in a pdf file http://www.caban.nl/Sennheiser.pdf.
Btw never never use zener diodes in sensitive audio circuits.

 

[Grim Reaper]

I built a couple of converters earlier this year, based on the circuit Ruud shared above. It fits into a Neutrik NA housing, if you don‘t want to wait for PCBs this is probably the fastest option.

Where did you get the box with the XLR connectors?

 

[waltzingbear]

More info at
http://www.uneeda-audio.com/phantom/

 

[Grim Reaper]

Ive ordered some proto boards. On the slow boat from china, about 3weeks.

Did you get the boards?

 

[corgan4321]

The simplist way to achieve this is described in a pdf file http://www.caban.nl/Sennheiser.pdf.
Btw never never use zener diodes in sensitive audio circuits.

Could you expand on the zener diodes? I built the Uneeda circuit with the 12V zener diode and it works… but the mic is noisy. I don’t have another 12V source to see if the noise is from the zener or not but your comment has me thinking.

 

[mrclunk]

Yes! Finally...
How many do u want?
I think i have spare smt parts i can chuck in with the pcbs or do u want complete modules?

Did you get the boards?

 

[MichelN]

Zener Diodes are extremely noisy. So much so that they are often used as noise generators in e.g. synthesizers. To make things worse, the amount of noise rises with the rated zener voltage. In most circuits this is not good but for T powered microphones this is much more critical since EVERY noise, hum etc of the power supply is directly added to the audio signal. Placing a large capacitor parallel to the zener helps only a little because the internal impedance of the zener is very low and to suppress the noise in you need a really big capacitor (think of 1000uF or so).

If you do not trust the circuit from my previour post and you really want the zener based circuit, at least replace the 12 volt zener by 2 6.2 volt zeners in series. That helps a little. Better is to use leds for the voltage srtabilisation. A blue or white LED had a forward voltage of approx 2,5 .. 3.0 volt, so with 4 or 5 in series you also have a reasonable stable 12 volt with much less noise.

 

[corgan4321]

Zener Diodes are extremely noisy. So much so that they are often used as noise generators in e.g. synthesizers. To make things worse, the amount of noise rises with the rated zener voltage. In most circuits this is not good but for T powered microphones this is much more critical since EVERY noise, hum etc of the power supply is directly added to the audio signal. Placing a large capacitor parallel to the zener helps only a little because the internal impedance of the zener is very low and to suppress the noise in you need a really big capacitor (think of 1000uF or so).

If you do not trust the circuit from my previour post and you really want the zener based circuit, at least replace the 12 volt zener by 2 6.2 volt zeners in series. That helps a little. Better is to use leds for the voltage srtabilisation. A blue or white LED had a forward voltage of approx 2,5 .. 3.0 volt, so with 4 or 5 in series you also have a reasonable stable 12 volt with much less noise.

Thanks for this info! I will dive back into this when I have a chance. The other circuit you posted, how does it work? It’s just a voltage divider?
It’s interesting other people here are using the Zener circuit with acceptable results…