Cool use for Primo EM200/204

[k brown]

Was reading about the concept behind the Schoeps V4U, and decided the EM200 was a good candidate for a DIY version of something similar, since it has such unusually flat response. Looking at the response of the V4U, that could only come from a flat-response capsule, as the HF lift would be created by the 33mm ring around it.

I cut a ring from high density fibreboard, filed/sanded it to the beveled shape, and epoxied it to a piece of carbon fibre tube. Other end fitted to an empty DIN plug shell, with a hard-wired cable. Electronics in a separate box at end of cable; adapted from a Samson C02.

For those unfamiliar with the V4U, Schoeps wanted a vocal mic with LDC qualities, but utilizing an SDC capsule. The 33mm ring provides an LDC-like top boost, as well as increasing the capsule's proximity effect, and making it more directional; transitions from cardioid below frequencies related to the size of the disc, to supercardioid above that point. V4 U | Studio Vocal Microphone | SCHOEPS Microphones The DIY version exhibits all those attributes, and the differences in sound between the 'naked' capsule and one with the ring are quite remarkable.

It's overall sound on voice at close distance is amazingly similar to the Oktava 319 and AT2035, but rejects much more room sound than either of them.

I'll try to record some comparisons (just my voice).

 

[kingkorg]

Exceptional read, thank you!

 

[jarvis]

Really cool project, looking forward to the comparisons!

Best
Jannis

 

[abbey road d enfer]

I love that kind of DIY; thinking out of the box, instead of rehashing an umpteenth version of a U47.

 

[mjrippe]

I love that kind of DIY; thinking out of the box, instead of rehashing an umpteenth version of a U47.

Agreed. Never seen this Schoeps mic before, let alone a DIY version.

And agreed that the "U" in U47 does not stand for "Umpeenth"!

 

[k brown]

Some tests (with just my voice).

First comparison is with AT2035. Mics were nearly touching, and about 1 foot away.

Same with second test, but with massively modified Oktava 319. All electronics replaced with crazy-simple tube circuit based on Royer's 'Country Boy's' project, but using a 6AU6 pentode instead of 5840 submini. Literally all there is in the mic is the tube itself; the capsule is connected directly to the tube and is polarized by grid leakage. The cathode resistor is in the power supply. Capsule resonator disc removed, and body shortened and heavily damped inside. Stock meshes left in place.

When I get time, I'll post comparisons to the same capsule without the ring, to demonstrate the changes in tonal balance and directivity.

Here's another candidate for this: JLI-1318. No built-in FET. I have two on the way; I'll pair with 2SK660, since I have several biasing/powering modules for those already.

 

[craigmorris74]

Some tests (with just my voice).

First comparison is with AT2035. Mics were nearly touching, and about 1 foot away.

Same with second test, but with massively modified Oktava 319. All electronics replaced with crazy-simple tube circuit based on Royer's 'Country Boy's' project, but using a 6AU6 pentode instead of 5840 submini. Literally all there is in the mic is the tube itself; the capsule is connected directly to the tube and is polarized by grid leakage. The cathode resistor is in the power supply. Capsule resonator disc removed, and body shortened and heavily damped inside. Stock meshes left in place.

When I get time, I'll post comparisons to the same capsule without the ring, to demonstrate the changes in tonal balance and directivity.

Here's another candidate for this: JLI-1318. No built-in FET. I have two on the way; I'll pair with 2SK660, since I have several biasing/powering modules for those already.

Curious if you ever tried that JLI capsule. I have a larger JLI-2555BXZ3-GP in a Country Boy mic and it's pretty bright. I was wondering if the JLI-1318 has as flat a response as the datasheet indicates?

 

[k brown]

Rejected for this purpose - despite the published graph, my examples were too bright; this requires a dead flat capsule, and the Primo is the only one I've found. The little JLI is not as bright as the 2555, but not flat enough for this.

By the way, I mis-identified that part - it's JLI-1813, not 1318.

https://www.jlielectronics.com/microphone-capsules/jli-1813/

 

[craigmorris74]

Rejected for this purpose - despite the published graph, my examples were too bright; this requires a dead flat capsule, and the Primo is the only one I've found. The little JLI is not as bright as the 2555, but not flat enough for this.

By the way, I mis-identified that part - it's JLI-1813, not 1318.

https://www.jlielectronics.com/microphone-capsules/jli-1813/

Bummer. Those capsules are the right price. The 2555 in the country boy circuit had a brighter top than my C12 style mic with a Tim Campbell CK12-not a good thing.

 

[ccaudle]

I was browsing this and a couple other threads which mention EM204, so I went to https://primomic.com/products/ and can't find EM204. Anyone know if it is discontinued recently?

 

[k brown]

Apparently Micbooster still has both EM200 and EM204 in stock.
https://micbooster.com/microphone-capsules/138-primo-em200-cardioid-electret.htmlhttps://micbooster.com/microphone-c...9-type-no_wires/36-matched_capsules-unmatched
EM204 is 2-wire connection (despite the three solder pads), and EM200 is the preferable 3-wire connection.

Interesting that Primo no longer lists either one. Maybe they've gone OEM or wholesale-only on those. They no longer list any 14.6mm capsules.

Even weirder, both the 200 and 204 are still shown in the photo-crawl at the top of the page (?).

 

[ccaudle]

Apparently Micbooster still has both EM200 and EM204 in stock.

Isn't Primo in Japan? I'm in the US, so going from Japan to MicBooster in the UK to me in the US seems like the long way around.
Plus I missed buying them when the pound crashed and I would have had a better exchange rate, so I'm a little bitter about missing out on a bargain.

I'll contact Primo US and see if they can still get some.

 

[ccaudle]

I'll contact Primo US and see if they can still get some.

Primo USA confirmed that EM200 is discontinued and no longer available for new purchase. That likely means that once MicBooster is out of their current stock you won't get more.

 

[k brown]

Did you inquire about the 204 as well?

 

[ccaudle]

Did you inquire about the 204 as well?

No, I was not so interested in that one since it doesn't bring out all the JFET terminals. My guess is that 204 is also EOL since it has been removed from the web site. I got a response within the day, so you could ask them explicitly if you care specifically about 204. I just wrote on the "contact us" page at primomic.com.

 

[k brown]

I got a great deal on 204s on eBay, so I did kingkorg's mod to convert them to 3-wire:
https://groupdiy.com/threads/primo-em204-to-em200-modification.77064/
Thanks, 'kk'!

My job wasn't nearly as tidy as his, because I didn't have a bit that small, but it worked fine, and I just plugged the hole afterward.

 

[kingkorg]

I believe i got some of those as well, it was a member of micbuilders group who had a stock. They were all sold last time i asked

 

[ccaudle]

Does Primo have any current capsules that are comparable to EM200? It seems like it is pretty low noise and flat response for a reasonable price OEM capsule. All the current seem to be 10mm, which I would assume have slightly worse SNR. Any which are as flat? The smaller capsules should maintain their response to a somewhat higher frequency, no?

 

[k brown]

I believe i got some of those as well, it was a member of micbuilders group who had a stock. They were all sold last time i asked

It was Len Moskowitz.

Blame me - I bought the last piece of his stock he was selling on eBay. I'd bought two, then after being so impressed with them, I went back to buy two more and he only had one left. By that time, Micbooster had more than doubled their price. So I made one as an imitation V4U, and the other two with removable rings, so can be used as flat-response cards.

Don't know why he didn't offer any mics made with those lovely capsules; maybe he had 'inside info' that they were going to be discontinued.

 

[k brown]

All the current lo-noise cards are pretty weak at the bottom, compared to 200/204.

https://www.primo.com.sg/components/