Cad Equitek E100 Capsule

[rock soderstrom]

Right? I am kind of mad at myself I haven't discovered these earlier. At the beginning i had an idea to just use capsules for some other mic projects, but that would be such a shame. I converted mine to p48, and that was it.

I agree, I will leave the mic as it is. I tried it last night with acoustic guitar and voice. What was really striking is the good resolution and the noble treble. The mic is not zingy at all, sounds great. Nothing is missing, I'm impressed for now. I will test it more tomorrow....

My plan is to buy a few more of these mics. I'm also looking at the cheaper models with fixed cable, I hope there are some with this capsule. That would be cool to tinker with.

 

[kingkorg]

Bang! I wasn't expecting this one to be on the list. Awesomeness! Josephson e22s.

 

[k brown]

Wow - that IS a surprise. Maybe custom spec'd for Josephson? Supposedly Primo did that for the Nak mics.

From other photos I've seen, it looks like he's not using the multi-hole 'phase disc'.

 

[rock soderstrom]

Bang! I wasn't expecting this one to be on the list. Awesomeness! Josephson e22s.

Ha, that's interesting

Any gutshots from the electronic inside? FET Cascode + Lundahl transformer?

 

[Khron]

Bang! I wasn't expecting this one to be on the list. Awesomeness! Josephson e22s.

I wonder how the pipe the capsule is at the front of, affects the frequency response and pattern. Looks like a longer path than in the Nakamichi / EMU mics.

 

[kingkorg]

I wonder how the pipe the capsule is at the front of, affects the frequency response and pattern. Looks like a longer path than in the Nakamichi / EMU mics.

Nice catch! I haven't had a chance to try the Josephson, but from my experience that kind of thing never works well. I would at least make km84 style slits behind the backplate.

@rock soderstrom, no idea unfortunately.

 

[Khron]

Nice catch! I haven't had a chance to try the Josephson, but from my experience that kind of thing never works well. I would at least make km84 style slits behind the backplate.

The dimensions / frequencies are obviously different orders of magnitude, but i remembered about some of Siegfried Linkwitz's work on open-baffle speakers:

https://www.linkwitzlab.com/H-U woofer2.htm
But then again, since it's a microphone and not an acoustic radiator / emitter, that would only (or mostly) affect the signal coming in from the rear... Wouldn't it?

Might be interesting to test out, if you still have any Primo capsules at hand

 

[kingkorg]

I might do just that! The chamber in the rear creates resonances that affect the front response as well. My educated guess would be that there will be a notch created in the response. I will check, and report.

 

[k brown]

Is it known if that 'pipe' is filled with absorbent material or not?

Might also be relevant that Josephson designed the mic to be used very close to sources, primarily close-mic'ing of drums.

 

[kingkorg]

Is it known if that 'pipe' is filled with absorbent material or not?

Might also be relevant that Josephson designed the mic to be used very close to sources, primarily close-mic'ing of drums.

No way of knowing. However, absorbent material would not change anything, the issue is extended path for the sound to reach the back of the capsule.

The dimensions / frequencies are obviously different orders of magnitude, but i remembered about some of Siegfried Linkwitz's work on open-baffle speakers:

https://www.linkwitzlab.com/H-U woofer2.htm
But then again, since it's a microphone and not an acoustic radiator / emitter, that would only (or mostly) affect the signal coming in from the rear... Wouldn't it?

Might be interesting to test out, if you still have any Primo capsules at hand

At least i have my acoustics theory right. Here are the responses of the "nude em21 capsule" (green) and with additional Josephson style quickly improvised ring in the back (blue). And the image of what my improvised assembly looks like.

I'm not saying Josephson looks like this, but if i, again, have my theory in place there is no way of avoiding this type of notch with that kind of assembly.

 

[abbey road d enfer]

But then again, since it's a microphone and not an acoustic radiator / emitter, that would only (or mostly) affect the signal coming in from the rear... Wouldn't it?

That is correct. In a single-diaphragm caridoid mic, directivity is achieved by directing a delayed wave to the back of the diaphragm.
It's usually done with an acoustic low-pass filter where the propagation delay is calculated to compensate the acoustic paths difference. Actually it works only over a restricted frequency range, as most datasheets show; rear rejection is generally best at midrance and decreases significantly at low and high frequencies.
The equivalent circuit is an RC, where resistance is that of the acoustic filter, and capacitance that of the diaphragm.
An alternative is to use an acoustic LC filter, where the inductance is a length of tube and no (or very little) acoustically resistant material is used.
It is probably the Josephson approach. Of course almost any combination is possible.

 

[Khron]

https://64.media.tumblr.com/816f8d50698d8c58de8dc5e1e315fc6e/tumblr_ol6jllqlcF1ql1t1ro1_1280.jpg
Spec sheet says the body diameter is 21mm, and headbasket is 30mm diameter, so the length of the tube might be ~23mm, eyeballing it? Just a smidge longer than the body diameter.

https://cdn.shopify.com/s/files/1/0278/8134/1022/products/e22s_3_1445x.jpg?v=1600154070
Headbasket looks pretty empty.

 

[kingkorg]

One more thing. The diaphragm side is somewhat buried within the enclosure with beveled edge. That will also alter the response.

If anyone ever gets their hands on one of these, the notch should be quite easy to spot by recording pink noise through a studio monitor. As these notches are usually quite deep, they would be easily noticeable.

I'm still hoping someone will start a project making these adapters for mxl603 type of bodies.

 

[k brown]

https://64.media.tumblr.com/816f8d50698d8c58de8dc5e1e315fc6e/tumblr_ol6jllqlcF1ql1t1ro1_1280.jpg
Spec sheet says the body diameter is 21mm, and headbasket is 30mm diameter, so the length of the tube might be ~23mm, eyeballing it? Just a smidge longer than the body diameter.

https://cdn.shopify.com/s/files/1/0278/8134/1022/products/e22s_3_1445x.jpg?v=1600154070
Headbasket looks pretty empty.

Ah - great shot.

Seems pretty clear, this mic was designed for a very colored response for close-micing drums (designed at the request of Steve Albini, wasn't it?).

 

[rjb5191]

The Teac ME-50 doesn't use this capsule, instead it uses a (Primo-)capsule like shown below and used in the Nakamichi CP-4 and in tons of other mics.

It looks like someone has been doing some moddin' and swapping. Can you talk about the difference between those OPA1642 and 1612 vs stock? Did those UES bipolars make a difference against the stock IC caps?

 

[kingkorg]

Just an idea i started working on yesterday. Only shielding it will need is at the back of the capsule where i will make a dome made out of some mesh. Due to the lack of any kind of grille the response measures smooth as a baby's bottom.

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

 

[k brown]

Great minds . . . My quasi Schoeps V4U-type mic:

- Primo EM204N 14.6mm capsule mntd in MDF ring attached to carbon fiber tube, terminated in DIN plug housing with hard-wired cable. Done up in Schoeps-ish dull grey.

- Black silk over capsule to keep dust out.

- Metal mesh over rear of capsule for screening.

 

[kingkorg]

Damn, awesome!

 

[k brown]

Thanks!

That ring gives a dead-flat cardioid capsule really unique properties; sounds amazingly like an LDC.

 

[abbey road d enfer]

This paper is not very convincing, seems to have been written by the marketing manager with little contribution from R&D.