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

[poctop]

yes looking through a catalogue is a horror. I found these 1000g isolation resistance !!
http://de.farnell.com/standexmeder/dip05-2a72-21l/reed-relais-5v-2xschliesser-ohne/dp/1079443

great find,  thanks for that,
finding something equivalent in term of package as the panasonic would be even greater
Best,
Dan,

 

[e.oelberg]

finding something equivalent in term of package as the panasonic would be even greater

d'accord looks like all high resistance relais are reed I keep searching

nb

 

[e.oelberg]

soooo twenty datasheets later I must confess all DIL packages have max 1 Gigaohm insulation resistance, and this is before the first switching, after that it goes down even lower, mmmh

 

[poctop]

As you can see here those Relay have been used in the BlackSpade UM25 Line From Oliver ,  as they were suggested to me ,
this was actually my reference .

Best,
Dan,

 

[Veronica Sneesby]

Hi guys, here is the body that we have been making for this build. It had been some work to get perfect. The bases are being nickel plated today and the body's are getting there powder coat. I have a few spares if anyone would still like one. There is no compromise on quality here, they are all Australian made.  I have also had a few PSU cases sold for this build with our toroidal transfer and Neutrick connectors. This should sound amazing.

 

[trans4funks1]

Is that one of your 60mm bodies adapted with a base that uses straps that are angled inwards towards the pcb's mounting holes?

Looks good!

 

[mics]

Is that one of your 60mm bodies adapted with a base that uses straps that are angled inwards towards the pcb's mounting holes?

Looks good!

Hi there.  This is a 51mm body that has been made for this build.  The rails are stainless and fit the pcb perfectly.  Thanks.

Ben

 

[Andydrum82]

Here's my Elam build coming along. I'm using a Beesneez PSU & body kit/capsule. Big thanks to Ben & Veronica for coming on board with this one 

 

[Winetree]

This wiring  has not been clearly posted and I can't tell by the pictures.
I'm wiring up the 7 Pin XLR on the mic to the Mic P.C.B.  I have two  connections left,  FB and OMN.
Are these  where the two connections from the selector switch on the Power supply connect to?

 

[poctop]

This wiring  has not been clearly posted and I can't tell by the pictures.
I'm wiring up the 7 Pin XLR on the mic to the Mic P.C.B.  I have two  connections left,  FB and OMN.
Are these  where the two connections from the selector switch on the Power supply connect to?

FB is actually F8 and OMN is the Omni pattern,

those 2 pads will accommodate wiring from the pattern switch , one position of the pattern switch will remain empty as there is no power required for the realy in cardiod ,

then  the 6V power from psu pcb pad (Relay) will be sent via pattern switch to OMN and F8 up on the mic pcb to control the pattern ,

Hope this helps,
Dan,

 

[Winetree]

FB is actually F8

That's why I use a magnifier when I solder.
So , the Figure 8 side of the switch goes to F8, and the omni side goes to OMN.
Thanks. 

 

[poctop]

FB is actually F8

That's why I use a magnifier when I solder.
So , the Figure 8 side of the switch goes to F8, and the omni side goes to OMN.
Thanks.

Correct ,  ,
Best,
DAn,

 

[Winetree]

Another pair ready to  go.
Just need to install my T.C. capsules and the tubes.

 

[poctop]

Another pair ready to  go.
Just need to install my T.C. capsules and the tubes.

Nice ,    hoping you will let us know how you like them.
Best,
Dan,

 

[trans4funks1]

What sort of notes are written on those capsule boxes?

 

[poctop]

What sort of notes are written on those capsule boxes?

Probably instruction for connection and a super important notice do not remove until soldering is done  8),
D.

 

[Winetree]

Yes.
" Do not remove until making connections"

 

[trans4funks1]

Thanks for explaining. Mine didn't come with that note, but I got the message.

 

[e.oelberg]

hi poctop

another dozend datasheets later i found a compatible, cheap relais with 1gigaohm at 500vdc ... what you think any downsides of this candidate ?

http://de.rs-online.com/web/p/monostabile-relais/0351819/

 

[poctop]

hi poctop

another dozend datasheets later i found a compatible, cheap relais with 1gigaohm at 500vdc ... what you think any downsides of this candidate ?

http://de.rs-online.com/web/p/monostabile-relais/0351819/

This looks like a very good candidate,  I went in and check upon the specsheet again for both ,
it seems this one is only a 1 mm higher than the other one used in the Bom , and the package is perfect
the spec sheet for the panasonic says Minimum 100M at 500VDC  and the one you have found is Min 1Gig at 500VDC,
wich is very good indeed, 
Since we are very far of those critical limit , it is hard to predict a normal operation Value. but i would expect them to be higher than that a much lower normal operation.

In term of power and current draw they are very very similar.
I went ahead and try sourcing it trough mouser or digikey and they seems to be out of reach or non stock at those location ,
even newark has no stock. 

I would consider the low Power one V23105A5002A201 to be a good candidate for further testing and experimentation.
if you can get a hold of them that would be very interesting to see if there is a noticable difference with those,

Again Thanks For the suggestions and findings  hoping you will let us know the outcomes,

Best ,
Dan,