Cad Equitek E100 Capsule

[k brown]

Sure, there's a lot of fluff in the Schoeps paper, however, even my DIY imitation sounds just like the paper describes - I was sceptical myself till I built it and heard the result.

 

[kingkorg]

Thanks for this!
I just took a look at the V4U capsule, saw the back of it. I swear i wasn't aware of this mic until now. LoL!

 

[k brown]

More info on my Gearspace thread:

https://gearspace.com/board/all-thi...g-mk4.html?highlight=schoeps+v4u#post15709431

 

[kingkorg]

It's almost funny how the people at GS had basically no clue what you were doing there. I'll have to try this out, i have some small sdcs around. Great audio examples there as well. Your mic sounded very Neumann-esque compared to the 319 and AT.

 

[k brown]

That Primo is a prettty amazing little capsule.

I built another pair where the rings are removable, so can be used as 'conventional' cardioids.

 

[kingkorg]

Pretty much done

 

[k brown]

Very elegant. How did you afix the capsule to the tube? Epoxy?

 

[kingkorg]

There's a screw holding it in place. Similar to Geffel M7 holder/capsule assembly.

 

[k brown]

So you drilled and tapped the mic capsule? - that's brave!

 

[kingkorg]

These are super easy to manipulate and modify. I also check the performance before and after.

 

[Khron]

The fet and 1G resistor are placed at the backplate.

IF4500? Or some other JFET?

 

[kingkorg]

2sk208. I tried IF4500 but it really needs that Rode topology to shine, it's not a easy drop in replacement fet. It has quite high input capacitance, which is not an issue with Rode's solution.

2sk208 has also pretty high Vgds, so i have some plans for that one in future

 

[Khron]

And would one want higher or lower Idss?

 

[kingkorg]

I guess that would depend on circuit. In Schoeps all the current not used by the fet would be wasted by the zener.

 

[k brown]

These are super easy to manipulate and modify. I also check the performance before and after.

I take it that entailed complete disassembly of the capsule?

 

[kingkorg]

Yes. I had to drill a hole as well for source/drain wires to come through.

 

[capacitor]

How's the longevity of the older EM21 (Primo) capsules?

I have a couple of them. I'd like to test to determine whether the electret still has a decent charge. I do have a decent set of ears (albeit not exactly golden), and an older-but-decent lower end preamp. Any thoughts? I'm looking for more of a pass-fail thing.

 

[k brown]

All of mine are quite old and from various Teac and Tascam mics - they all have output comparable to every other electret I have (and to each other); clearly they are back-electrets, which don't have the aging problem of the older Sony (non-back) electrets.

 

[capacitor]

Thanks! I've got a pair of the Teac ME-80/ME-120 mics, with the idea in mind to update them with better electronics & phantom power. Now I get to stay up late learning about back electret self-polarized SDCs, haha!

 

[rock soderstrom]

How's the longevity of the older EM21 (Primo) capsules?

I bought over 10 similar mics with EM21 last year. Random and untested, none of them had a problem with it.

Since these mics often lie unused for over 30 years in some drawer, it sometimes happens that the batteries leak or the rubber spacers of these become brittle. But all this does not affect the capsules, mine all work without problems.