Telefunken ELA M 251 Clone Tube Microphone Build Thread (D-Ela M 251E)

[poctop]

Oh, I forgot to add that it can be ordered in any of the standard BeesNeez colors, with no upcharge. These are professional paint and powder coating jobs.

Too big is actually a good thing for DIYer, what is the lenght of the Beez mic body.
LEt me know i will check the lenght of the pcb  .
Best,
DAN,

Sleeve diameter, from the back of my head, is 51 mm or 2 inches. I'd have to check for length (I believe it was mentioned in older adds), but perhaps Ben or Veronica could chime in.

Anyway, here's the current add (without sale):
http://www.beesneezmicrophones.com.au/store/index.php?_a=viewProd&productId=99

Hey guys inside the BeesNeez 251 body there is 119mm of clearance for a PCB. PCB width can be up to 48mm wide. Our 251 body is 51mm the same as the original.

Sorry for the delay in seeing this post, it was a busy weekend.

Thanks,

N.B

PCB Dimension :

Lenght:  126mm
this is a Taper PCB
PCB maximum Width: 38mm
PCB Minimum Width at bottom of pcb Width: 36mm
Side Rail Clearance Minimum Required : 2.5mm

Fit shown is HT-11 Mic body

Best
Dan,

 

[poctop]

So Dan.... what's the current draw of each bit of the circuit??

120v and 6.3V parts?

Thanks !

110V B+ not really much this is plate current  : <1ma

or you can do this  (B+(V))-(Plate Voltage(V))/Plate Resistance = Plate Current.


6.3V Heater in parralelle  6072 Tube Data sheet : 350ma


Hope this helps,
Best,
DAN,

 

[Woot]

Lenght:  126mm
PCB maximum Width: 38mm
Side Rail Clearance Minimum Required : 2.5mm

Best
Dan,

Re the Beezneez body...

Yep, so similarly to the Matachung board it is ~7mm too long.... But looking at the board, we may be able to bring it in on each side by a couple of millimetres so it fits into the bottom bit (see photo). The bottom part is approx 22mm deep, some of which will be taken up by the xlr wiring....

Otherwise, I presume I'll have to cut all of the board off from the trafo down and directly wire all of the xlr connectors to their destination... DAn, will there be much of an issue doing this?

Cheers,

MAtt

 

[poctop]

Lenght:  126mm
PCB maximum Width: 38mm
Side Rail Clearance Minimum Required : 2.5mm

Best
Dan,

Re the Beezneez body...

Yep, so similarly to the Matachung board it is ~7mm too long.... But looking at the board, we may be able to bring it in on each side by a couple of millimetres so it fits into the bottom bit (see photo). The bottom part is approx 22mm deep, some of which will be taken up by the xlr wiring....

Otherwise, I presume I'll have to cut all of the board off from the trafo down and directly wire all of the xlr connectors to their destination... DAn, will there be much of an issue doing this?

Cheers,

MAtt

finding 3.5mm on each side would be best , but you could jump the connection but it will not be very "elegant",
but after all this is DIY so scraping a bit of metal for this particular body could also be possible ,  ,
following the next episode,
Best,
Dan,

 

[poctop]

Lenght:  126mm
PCB maximum Width: 38mm
Side Rail Clearance Minimum Required : 2.5mm

Best
Dan,

Re the Beezneez body...

Yep, so similarly to the Matachung board it is ~7mm too long.... But looking at the board, we may be able to bring it in on each side by a couple of millimetres so it fits into the bottom bit (see photo). The bottom part is approx 22mm deep, some of which will be taken up by the xlr wiring....

Otherwise, I presume I'll have to cut all of the board off from the trafo down and directly wire all of the xlr connectors to their destination... DAn, will there be much of an issue doing this?

Cheers,

MAtt

Here is even more details ,
Lenght:  126mm
this is a Taper PCB
PCB maximum Width: 38mm
PCB Minimum Width at bottom of pcb Width: 36mm
Side Rail Clearance Minimum Required : 2.5mm

 

[Dylan W]

What are the dimensions of the coupling cap cutout?

 

[Woot]

So Dan.... what's the current draw of each bit of the circuit??

120v and 6.3V parts?

Thanks !

110V B+ not really much this is plate current  : <1ma

or you can do this  (B+(V))-(Plate Voltage(V))/Plate Resistance = Plate Current.


6.3V Heater in parralelle  6072 Tube Data sheet : 350ma


Hope this helps,
Best,
DAN,

Sorry DAn.... I'm really too n00b to figure this out...can you help please?

So are R1 and R2 acting as a voltage divider? Where does the trimmer come in? Is it in series with one of the resistors?

I plugged these numbers into a voltage divider calculator but the answers didn't make any sense to me... for a 200v input and 110v output, it's suggesting around 91k for R2 if R1 is 75 k. This would make sense for a 75 k resistor and a 25k trimmer... But I'm not sure where the 200k trimmer fits in?

For a 220v inout and 110 volt output R1 and R2 are the same value... 100k, 80k, whatever. So what would you suggest?

Thanks for any advice!

 

[micaddict]

Well, the slight oversize is a bummer. Of course both Matador and Dan's PCB were based on the long and slender HT-11a body; not necessarily an original Ela M. And Matador's is in fact the C12 PCB to begin with. I guess Dan could theoretically shrink the whole PCB lengthwise by 5.5%, but that would send him back to the drawing table, meaning extra time, energy and money. Not the best scenario for him probably. On the other hand, should very accurate clone bodies (looking like the two originals, earlier posted in this thread) become available, it may be a good thing if there were a PCB fitting the original thing. The same holds for the U67 BTW.
But that's missing the point, of course. I can't speak for Dan, but it seems to me that the whole idea of his PCBs is accurate, classic circuits for affordable, well-available bodies. Those who want the exact look of an Ela M251 will probably want the clear plastic inside, too.
Hey, but the D-49 does come in a square and round version. Hmmm..... 
Just playing around there, Dan. It's your show and a fine show it is!

Conversely, should there still be a BeesNeez collaboration, it might be possible for them to cut slightly longer sleeves from the rough tube. But that would mean adding longer rails, as well. So I guess that would call for a serious amount of bodies to be worthwile.

Oh well, it was worth trying. I like the heavy BeesNeez weapons.

Yes, perhaps a little filing here and there will do the trick. After all, it's DIY.

Carry on.

 

[poctop]

What are the dimensions of the coupling cap cutout?

41 x 16mm
Best,
Dan,

 

[Woot]

^^

Sweet, this should also fit:

Auricap XO 400v 26 x 33mm (DxL)
Mundorf M-Cap 400v 17 x 34mm (DxL)

if anyone considering using them...

 

[poctop]

So Dan.... what's the current draw of each bit of the circuit??

120v and 6.3V parts?

Thanks !

110V B+ not really much this is plate current  : <1ma

or you can do this  (B+(V))-(Plate Voltage(V))/Plate Resistance = Plate Current.


6.3V Heater in parralelle  6072 Tube Data sheet : 350ma


Hope this helps,
Best,
DAN,

Sorry DAn.... I'm really too n00b to figure this out...can you help please?

So are R1 and R2 acting as a voltage divider? Where does the trimmer come in? Is it in series with one of the resistors?

I plugged these numbers into a voltage divider calculator but the answers didn't make any sense to me... for a 200v input and 110v output, it's suggesting around 91k for R2 if R1 is 75 k. This would make sense for a 75 k resistor and a 25k trimmer... But I'm not sure where the 200k trimmer fits in?

For a 220v inout and 110 volt output R1 and R2 are the same value... 100k, 80k, whatever. So what would you suggest?

Thanks for any advice!

When i have time i will probe my mic to find out exactely the current draw at 110B+
i have made a dropper resistor caculator with excel that i will share also,
Best,
Dan,

 

[Melodeath00]

Well, the slight oversize is a bummer. Of course both Matador and Dan's PCB were based on the long and slender HT-11a body; not necessarily an original Ela M. And Matador's is in fact the C12 PCB to begin with. I guess Dan could theoretically shrink the whole PCB lengthwise by 5.5%, but that would send him back to the drawing table, meaning extra time, energy and money. Not the best scenario for him probably. On the other hand, should very accurate clone bodies (looking like the two originals, earlier posted in this thread) become available, it may be a good thing if there were a PCB fitting the original thing. The same holds for the U67 BTW.
But that's missing the point, of course. I can't speak for Dan, but it seems to me that the whole idea of his PCBs is accurate, classic circuits for affordable, well-available bodies. Those who want the exact look of an Ela M251 will probably want the clear plastic inside, too.
Hey, but the D-49 does come in a square and round version. Hmmm..... 
Just playing around there, Dan. It's your show and a fine show it is!

Conversely, should there still be a BeesNeez collaboration, it might be possible for them to cut slightly longer sleeves from the rough tube. But that would mean adding longer rails, as well. So I guess that would call for a serious amount of bodies to be worthwile.

Oh well, it was worth trying. I like the heavy BeesNeez weapons.

Yes, perhaps a little filing here and there will do the trick. After all, it's DIY.

Carry on.

Accurate bodies for U67 and 251 would sure be nice. I must say, however, that after my own very rudimentary tests (which I will continue), I'm no longer convinced headbaskets have as much to do with sound as many claim.

 

[Veronica Sneesby]

Conversely, should there still be a BeesNeez collaboration, it might be possible for them to cut slightly longer sleeves from the rough tube. But that would mean adding longer rails, as well. So I guess that would call for a serious amount of bodies to be worthwile.

Oh well, it was worth trying. I like the heavy BeesNeez weapons.

Yes, perhaps a little filing here and there will do the trick. After all, it's DIY.

Carry on.

Hi, I think that Dan's PCB looks great, so making the body tubes and rails longer is not a problem, but I will need numbers to order the metal and to make the changes. I will not go ahead with anything until we have some idea of what we are looking at.

Thanks, V
[email protected]

 

[micaddict]

^^^

 

[bockaudio]

Looks like a wet tantalum to me , but they may have had different type over times ,  as Metal paper, polyester also,
Why Not polyprop
Here is a shot ,.

I have only seen wet tantalums in stock 251's over the last 24 years. Any film caps were aftermarket repairs.

 

[Melodeath00]

Good point, David Bock. I have been unable to find any wet tantalums over 125V in the 3.3uF range, and they are very expensive. Do you think it's really worth it sound-wise, and is it dangerous to use a cap of 125V? And wouldn't it be dangerous for the transformer if the wet tantalum goes caput? I read that they short when they fail.

 

[Woot]

^

doing a wet tantalum search on the Vishay website yields some series of caps at higher voltages (180-200+) and appropriate capacitance. Don't know if any are OK for this application.

They may sell them to you although I wonder what the MQ would be

 

[micaddict]

Hi, I think that Dan's PCB looks great, so making the body tubes and rails longer is not a problem, but I will need numbers to order the metal and to make the changes. I will not go ahead with anything until we have some idea of what we are looking at.

Thanks, V
[email protected]

So .......

Anyone want me to start a feeler thread?



Henk

 

[braeden]

Hi, I think that Dan's PCB looks great, so making the body tubes and rails longer is not a problem, but I will need numbers to order the metal and to make the changes. I will not go ahead with anything until we have some idea of what we are looking at.

Thanks, V
[email protected]

So .......

Anyone want me to start a feeler thread?



Henk

Very interested in purchasing a CK12 and ELA body.

When are the PCBs available?

Thanks

 

[poctop]

Hi, I think that Dan's PCB looks great, so making the body tubes and rails longer is not a problem, but I will need numbers to order the metal and to make the changes. I will not go ahead with anything until we have some idea of what we are looking at.

Thanks, V
[email protected]

So .......

Anyone want me to start a feeler thread?



Henk

Very interested in purchasing a CK12 and ELA body.

When are the PCBs available?

Thanks

They will be returning when there is enough folks to make it happen I guess,
Best,
Dan,