Ela-M 251 Body from Aliexpress

[paulcheeba]

Have you guys seen the new version of that body with the E and the slot. Still looks too short though. There are no measurements. Looks a little more authentic.

 

[Barry Hufker]

Can you provide a link?

 

[paulcheeba]

https://www.aliexpress.com/item/1005006469418125.html?spm=a2g0n.productlist.0.0.26ff29afkVnFTb&browser_id=6da7a948cf7a4d14bfc94e3b429c1907&aff_platform=msite&m_page_id=rfkhqdxtacavrppp18d4f24c0bd211d823f723f922&gclid=&pdp_npi=4%40dis%21GBP%2140.10%2140.10%21%21%2149.50%2149.50%21%40211b600917064298251973081e9a79%2112000037309162161%21sea%21UK%210%21AB&algo_pvid=ea625a6b-a21b-4edb-b4b9-38b56510e962

 

[micolas]

https://www.aliexpress.com/item/1005006469418125.html?spm=a2g0n.productlist.0.0.26ff29afkVnFTb&browser_id=6da7a948cf7a4d14bfc94e3b429c1907&aff_platform=msite&m_page_id=rfkhqdxtacavrppp18d4f24c0bd211d823f723f922&gclid=&pdp_npi=4%40dis%21GBP%2140.10%2140.10%21%21%2149.50%2149.50%21%40211b600917064298251973081e9a79%2112000037309162161%21sea%21UK%210%21AB&algo_pvid=ea625a6b-a21b-4edb-b4b9-38b56510e962View attachment 121334

I don't know why, it blocks my access to the product

 

[rock soderstrom]

I don't know why, it blocks my access to the product

The link doesn't work for me either, but this link does. Nice body.

 

[micolas]

Wow, very nice!

 

[egroys]

The color looks a little more accurate on this new one. Has anyone verified that it's a similar build/dimensions to the yellower one?

 

[Wordsushi]

If you message the seller, they will often give you the inner measurements and even send pics. I'd be curious to see the inside of this mic, too.

*Note though that it is currently the Chinese Lunar Holiday season so there may not be any response for a few days.

 

[Jim50hertz]

The color looks a little more accurate on this new one. Has anyone verified that it's a similar build/dimensions to the yellower one?

I took a chance and ordered a pair. When they arrive I’ll post pics and dimensions.

 

[Papa Tango Charly]

I used these, removed the plastic and snuggled them in the holes i made. I cut the upper part in half.
View attachment 118039
Capsule front direct to grid (0v), backplate 60v, rear variable via psu.
Here's a sketch i used for build. Never meant to share it, i just drew in one night at work based on the originals, and added external pattern control.
View attachment 118040

Edit:
I added 120Meg and 15nF filter before HiZ pattern control resistor due to some low end buzz.

I have tried to make a schematic of the Kingkorg with "switch omni" C12 with a 6S6BV point to point pcb with 3U audio transformer. Could you guys take a look at it and tell me if i did it well. Thank you. Best

 

[doqmemory]

I have tried to make a schematic of the Kingkorg with "switch omni" C12 with a 6S6BV point to point pcb with 3U audio transformer. Could you guys take a look at it and tell me if i did it well.

What does R6 and C3 (1000 pf) do? Neither is needed for omni, just connect the rear diaphragm to the front to get omni.

Your "other" C3 (10 nF) is not correctly connected, since it blocks the polarization voltage to the backplate. Instead, R5 should directly go to the backplate and a 10 nF film capacitor should connect that node (R5-backplate) to ground.

For biasing the tube cathode, try using two UF4007 diodes in series to ground (cathodes of the diodes pointing to ground), as suggested by @terry setter with reference to U47 biasing in another thread.

 

[Jim50hertz]

 

[Jim50hertz]

These look great in person, much more cream coloured than yellow. Nicely finished and heavy.

If anyone can chime in and suggest how these dimensions might compare to the other version and the fit of the D251 pcbs that would be great, @HerbertR ?

Dimensions

Inner rails Length 124.5mm
Distance between outer edge of rails 40.5mm
Distance between screw holes 26.8mm

Body tube

Outer diameter 49mm
Inner diameter 43.65mm
Length 135mm

Headbasket

Length 65mm
Diameter front to back 50.8mm
Diameter side to side 50.8mm

 

[Papa Tango Charly]

Hello thank you for your help. I have changed the schematic. There is a 1nF in Kingkorg schematic, i would like to understand where it is placed and why. Thank you guy's for you help. Best

 

[Khron]

There is a 1nF in Khron's schematic

My schematic? Where?

 

[Papa Tango Charly]

Oups Sorry Khron my bad i meant kingkorg!

 

[Khron]

There is a 1nF in Kingkorg schematic, i would like to understand where it is placed and why.

If you look at an M49 schematic, it might become clearer.

In that case, as in @kingkorg 's wiring diagram, the signal is taken from the front diaphragm, and the backplate is at a fixed +60v bias. That 1nF is there between the front and the rear diaphragm, in order to pass a signal from the rear diaphragm to the tube grid.

When the rear diaphragm is at +60v you get cardioid (because there's no voltage difference between it and the backplate). When it's grounded (at 0v), same as the front diaphragm, you get omni (because both diaphragms are 60v BELOW the backplate). When the rear diaphragm is at 120v (60v ABOVE the backplate, and in the opposite polarity to the backplate-to-front diaphragm), you get fig-8.

 

[Papa Tango Charly]

Ok Khron thank you, I get it think, i should keep the 1nf condenser on the switch. . I have tried to translate Kingkorg sketch into a schematic. I would like to know if it's a faithful schematic reproduction of his sketch. Thank you. Drawing schematic is very pedagogic.

 

[Khron]

I would actually argue that R5 1gig is not even necessary in that position (it might even be a bad idea, possibly).

 

[MagnetoSound]

C3 should be on the other side of R5 where the backplate is, to couple the backplate to ground; and R5 should be connected between R4 and R3, the voltage divider. Otherwise you’ll see close to 120v on the backplate.

@Khron, R5 and C3 filter the supply to the backplate. Very important that this is spotless noise wise. Maybe not necessary if the B+ is already spotless, but why would it be a bad idea??