Topic: LD modification question, just an idea at this point? any precedence?

[BlueSky71]

Hey there, I picked up a warm audio U87 clone recently, the WA87R2. I thought I might try some MS recording with it here and there at some more of my local comfortable for taping venues as I have enjoyed the results and post tinkering in the past. This mic would be the Figure 8 in those cases. After buying it for a really nice price locally, I started looking at it and took it apart. It got me to thinking, has anyone here or elsewhere done the type of modifications to an LD that would remove the capsule and screen portion from the mic, rewire it, and concoct a suspension scheme and more the body and connector to a gear bag? The same as we often do SD mics? I can't stop looking at it, as the mic itself inside is pretty simple. If there is a project anyone knows of that has been done like this in the past, I would be interested in reading about it. Weird thought for the day now posted to interned forum. Thanks all

[Craig T]

I think what you're looking for is a remote lollipop style LD capsule.  I've never seen one, but seems possible.  Something like the Ear Trumpet Labs Myrtle (LD lollipop head in a suspension mount) with an extension cable to the mic body.

[Gutbucket]

Certainly possible.  Depends on your appetite and abilities with regards to DIY.  Some research into best practices for such things will be valuable in addition to reports on what others have done. Maybe try a search and possibly make a request for info at the forums below, which are focused on folks doing DIY audio stuff, some of which is very similar to what you describe:

Mic Builders list (dedicated DIY microphone project stuff)- https://groups.io/g/MicBuilders

DIY Forum (features a microphone subforum)- https://groupdiy.com/

..along with other sites you're more than likely to find.  Those two are just the first couple that come to mind.

[BlueSky71]

Looking into it more today, I would need a 5 conductor mic? cable to move what is here, down to what is there in the body. This would maintain the pad, pattern and cut switches. It would ideally be shielded, thin and flexible. Quad star might be an option if I use the shield? Any other ideas? 3 runs of 3031?

Also, if this is viable, maybe I end up with 2 of these, or a similar LD to run a stereo din, pas setup?

This actually seems like it might be easy if I can get a couple 3d printed pieces made.

[Ronmac]

Not a mod I would ever attempt, and I have 50 years of professional experience in the manufacturing and service field.

First rule of experimental modification: be prepared and able to completely reverse the process to bring it back to original spec.

Second rule of experimental modification: be prepared to accept it was a really bad idea, and buy a new microphone.

[Gutbucket]

^ All true. Be prepared for failure. Main reason to do it would be for fun experimentation.

I missed the part about moving the amplifier to the recording bag.  That might be tricky. There are challenges in dealing with high impedance signals over a significant distance. Quickly gets outside the realm of typical electrical mods, certainly beyond my abilities.  Ask around on the microphone builder forums!

[goodcooker]

If I understand what you are trying to do - remove the capsule assembly from a large diaphragm condenser mic and run it remotely from the electronics located in the mic body - you are not going to be able to accomplish that with a simple wire. Remote capsule mics have active electronics between the capsule and the circuit. In mics like the Schoeps Colette series and MBHO KA that circuit is located in the capsule connector (hence the term active cable). In a Neumann AK, Schoeps CCM or Beyerdynamic CK it is located in the capsule housing so the cable itself is passive.

Even if you could borrow one of the impedance converter circuits from one of these types of mics you would also have to figure out if breaking the ground (almost all mics are grounded to the metal sleeve/housing of the preamplifier creating an electrical shield from EMI) would turn the capsule half of the separated mic into an antenna.

If this were accomplished easily it would likely exist on the market already. But, I hope you try it and it works.

[Gutbucket]

Would be advantageous keep the FET / impedance converter section with the capsule assembly if that's possible, which would make the run to the remote-mounted remainder of the amplifier and powering circuitry less problematic.  But would still be very low level and susceptible to interference.

[DSatz]

No comment on the core question. Just wanted to point out that U 87-type microphones have considerably better symmetry in the figure-8 setting if you aim the "point" of the head basket forward (toward the center of the direct sound sources)(turned, of course, so that the capsule within the head basket is vertical), and let the amplifier sit behind it (i.e. horizontally), as opposed to the traditional studio placement in which the microphone is upright with the "point" of the head basket facing the ceiling.

[Gutbucket]

^ That also makes for a much more compact and less visually intrusive Mid/Side arrangement, since both microphone bodies are parallel to each other, oriented fore/aft.  Might sufficiently achieve the end goal in a far easier way!

No comment on the core question.

Was half-biting my tongue awaiting your response!

[DSatz]

> Was half-biting my tongue awaiting your response!

Um, please don't injure yourself. If the clone microphone is constructed the way the Neumann U 87 series is (this includes the U 67, the M 269, the U 77 and the present-day model U 87 A in addition to the U 87 itself), the capsule head can easily be removed from the amplifier/body; the capsule head has pins that plug into socket holes in the amplifier/body. So if someone made a similar socket and attached the FET stage circuitry to it, no modifications to the capsule head would be needed, and you would preserve the option of using the mike as originally designed OR using it with the (mainly) remote electronics.

Keep in mind that all the single-channel mikes of this series have rather sophisticated low-cut filtering (which in the U 67 was the subject of a patent, since it mainly occurs before the tube stage) and high-frequency reduction that involves the output transformer in a feedback loop. When the first batch of mikes with this type of capsule were assembled as prototypes, still under the name "U 60" (1960 having been the year of their planned introduction), the results turned out to be too bright- and harsh-sounding for the tastes of that time, and the roll-off network (according to the repair and calibration specs, 7 dB response reduction at 16 kHz relative to the 1 kHz sensitivity) was then added to the circuit to compensate.

This coincided with the name change, reportedly suggested by the late Stephen Temmer of Gotham Audio (Neumann's U.S. distributor and the person most responsible for their becoming aware of public relations and the importance of brand "image"), to "U 67". The new microphone was intended to replace the U 47, which was being discontinued since Telefunken no longer manufactured the VF 14 vacuum tube on which its circuitry was based; Temmer wanted to convey a sense of continuity with the older microphone. (See attached PDF from Neumann on the history of the U 60/U 67.)

--best regards

[BlueSky71]

Hey guys, so, had the FET been in the capsule, this was a viable idea. But I spent some time over on the DIY page that was linked earlier, and asked some questions. They suggested getting far more into the DIY aspect of the project. Anyhow, the project will not come to fruition with this mic, and I will put it down for a while. I tried out the mic the other day ar a local show, 1 channel only and while it does sound really nice, I am headed in a different direction for sure. Much more compact and lighter OC18's from Austrian Audio. They are just the cards, but found a nice deal and will try them out for a while, no surgery. I guess i never knew there were any electronics inside the mic couplers on the Nbobs and Nainat active sets where the capsule connects. So I learned a bit, thanks for the input everyone.

[DSatz]

ja, that's why the word "active" was originally used--to indicate the presence of active circuitry, an impedance converter that itself requires powering--in the extension device. That technology, which may seem obvious today, was brand new ~50 years ago and Dr. Schoeps and his company's director of development, Mr. Jörg Wuttke, were granted a patent on it.

Unfortunately the term is frequently used on this forum to mean any capsule extension device, whether active or not--which can create confusion, as you've just experienced.