Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Slainbabyyc]

Hello all,

I recently acquired an untested Neumann CMV3(A?), complete with the original Telefunken re 084 tube, an M5 capsule with "torpedo head" mount, and the original cable. I am missing a compatible power supply and accessories such as a swivel mount and other capsules. Does anyone on this forum know the model numbers of compatible mounts/power supplies, or which technicians might be capable of crafting the most true-to-original power supply?

Thank you

[klaus]

Hello,
Please post using your real name (please see the forum's "Ground Rules"). Thanks.

[Slainbabyyc]

Hello,
Please post using your real name (please see the forum's "Ground Rules"). Thanks.

Hi Klaus, changes made 👍 . Have you any thoughts on this mic? I believe it is the CMV3A variant.

[klaus]

Thank you.
Two suggestions:

1. wait a bit for helpful posts on the subject

2. peruse eBay.de. As the CMV3 was a German mic never exported to the U.S. the bulk of collectors are in Germany

[Slainbabyyc]

I will try that, thank you.

[Slainbabyyc]

I managed to learn the following model numbers:

Wooden battery box - Ela MZ 017/1
Metal battery Box - Ela MZ 018/1
Table stand with connector mount and 10m cable - Ela MZ 010/2
Suspension nipple with 20m cable - Ela MZ 012/2 (mine is 019/1, but I believe it is the same or at least very similar)

[klaus]

You have rather high aspirations for restoring an 80+ year old antique...  but all power to you. Keep us posted on progress.

[David Satz]

You seem unsure of which model amplifier you have. As far as I've been able to find out, the main difference between the CMV 3 and the CMV 3a was the manner of attaching a capsule. The capsules and amplifiers for this series were made with two different, mutually incompatible types of mechanical fixtures. The earliest types (the original CMV 3 arrangement, introduced in 1927) had threads which screwed directly into the "torpedo head" of the amplifier, which had a pivot built into it, or any of three electrically passive "gooseneck" extensions (30, 60 or 80 cm long) could be attached to the torpedo head and a capsule screwed onto the other end of the gooseneck.

A "bayonet" (push and turn to lock) connector was provided for the later model CMV 3a (introduced after 1930--perhaps in 1932), which had a corresponding socket and no "torpedo head". Thus the capsules made for this second type of amplifier sat a little farther from the body of the amplifier when in use. I believe, but can't prove, that there were three corresponding types of gooseneck extension for this type of amplifier as well.

Keeping track of these products is tricky because three independent systems of nomenclature were in use simultaneously: (a) Neumann's own; (b) Telefunken's "Ela" catalog names; and (c) whatever the German broadcasting authorities chose to call the equipment--all broadcasting at the time, including purchasing authority and "type approval" for equipment, being government-owned and centrally organized. Confusing matters further, sometimes one of the these nomenclatures (especially Telefunken's) would sometimes be revised while the others remained the same.

As an example, Neumann's CM 3 capsule was called the M 1-2 by German broadcasting and I haven't yet found any Telefunken catalog that listed it (though I certainly haven't seen them all), while the CM 5 (the original--later there was a CM 5a) was called M 1-2a by the broadcasters and "Ela MZ 026/2" by Telefunken when ordered as a separate item. Both capsules were introduced for the CMV 3 amplifier, which Telefunken called "Ela MZ 027/1". The complete microphone was called "Ela M 301/2" by Telefunken by 1939 but if I'm not mistaken, it had been given another "Ela M" designation earlier.

--Just as a footnote to your listing, there was a later-model metal battery box, which Telefunken listed as "Ela MZ 018/2" in their 1939 catalog. Also, the Ela MZ 012/2 and the Ela MZ 019/1 were different things; the first was a special cable 10 meters long (used in connection with the special connector "Ela MZ 024/2" for suspending the microphone--see photo below), while the second was a simpler 20-meter extension cable, with other lengths available to order.

--It's not really correct to call any microphone a "CMV" anything, since that acronym means "condenser microphone amplifier", i.e. the less salient part of the microphone, not the part that primarily determines its sonic and directional properties. In contemporary terms it's like when someone says that a recording was made with a "414", a "67" or an "M 221 B"--good, now we know what the microphone looked like, but that's about all (unless we assume that "professional microphone" always = cardioid as some people unfortunately do--and that was anything but true at the time we're talking about).

For that matter there was a convention among the older generation of microphone designers that the capsule on its own was sometimes called a "condenser microphone" while the amplifier was regarded as a "microphone accessory" along with cables, stand adapters, power supplies and so on. You can see that in Neumann's "CM" names for its pre-war capsules. (Names such as "M 7" come from broadcasting nomenclature rather than Neumann's own.) At Schoeps, an internal nomenclature for capsules still works this way over 70 years later.

--If you want to be truly complete in your collection of accessories, you might also look for the rain coverings that were offered for outdoor use -- they came in the set with the gooseneck extensions.

[Slainbabyyc]

The tricky thing about the mic that I have (or am soon to have in my possession, it's still on its way), is that it has the torpedo head, but without the pivot seen on the original CMV3. I am waiting to see when it arrives if the torpedo attaches to a bayonet connector (fingers crossed). It also features the original M5 capsule.

As far as I could tell from my review of an original Telefunken catalog, the "Ela M 301/2" designation refers to both the amplifier and the capsule which was included. There was also an "Ela M 302/1", and "303/1" that shipped with different capsules. Here is a link to the catalog I read: https://www.filmsoundsweden.se/backspegel/cmv3.html

The cable I will have actually features similar mounting hardware integrated into the connector. I have decided to sell it as I have no use for a suspension mount, and I will use the proceeds to fund my purchase of a new power supply and GAC-7 cable with a mic stand mountable connector from Peter Drefahl. Then will begin the process of rehabilitating the circuitry. I have given up on my dream of acquiring all original accessories for this mic, mostly because they are very rare and I don't want to wait longer to hear how it sounds! Thank you very much for the wealth of information you shared.

[David Satz]

Hmmm--your first photo shows an adapted version of the CMV 3 that I'm not familiar with. It has the universal ball joint of a CMV 3a, which normally was topped by a solid, cylindrical contact that a bayonet-equipped capsule could attach to. But Neumann apparently made a torpedo head adapter "Z 1" which provided an attachment for screw-on capsules, and maybe that's what you have there. I've never seen any such adapter listed in a Telefunken catalog, but as a rule their "Ela Sammellisten" included only selected items, and not everything that might have been available from the original equipment manufacturers.

Your second photo shows (among other things) a CM 5 capsule that looks like other capsules designed for the CMV 3's "torpedo head". As far as I know there was only one set of dimensions for bayonet attachments and one for torpedo-head attachments, so I would guess that your CM 5 will probably fit onto the adapter shown in the first photo.

Neumann's Web site has a scan of a different copy of the same Telefunken brochure that's on the Swedish site you referred to. One of the things I found interesting in it is that the pressure-actuated capsules--which, given their physical size, are omnidirectional at low and low-mid frequencies with a progressively narrower pickup pattern in the upper midrange and above--are described not as "omnidirectional" but as having a "normal" (!) pickup pattern. Neumann's capsules offered only this pattern originally, and his patent was written as if this were the only known or possible type of condenser microphone capsule. Western Electric and RCA's early condenser microphones, which preceded Neumann's by a number of years, were pressure transducers as well. The famous M 7 quasi-cardioid capsule and its M 8 figure-eight counterpart were designed only some years later by Braunmühl and Weber.

The M 5 had just this "normal" directional pattern and was diffuse-field equalized. So given its large size, on its axis it has a free-field response rise of over 12 dB as shown in the attached reference curve. This on-axis rise was broader than Neumann's older capsules had offered (e.g. the CM 3), and as the rest of the sound recording and reproduction "chain" evolved, I would think that this characteristic would offer a more "natural" overall sound than the older capsules, when placed at a suitable distance in a suitable acoustic. But by today's standards this is still an enormous on-axis response boost. By the time the NWDR developed the M 50-type microphone, they had moved to using small-diaphragm capsules instead.

[Slainbabyyc]

Very interesting to hear about the variable pickup as frequencies get higher, and to see that high res photo of the response! I was looking for something like that for a while! I am quite curious to see how usable this mic is in the studio, obviously the presence boost is enormous and the high frequency cutoff a tad early. That the polar pattern is not "true" omni is encouraging, it will be nice to have some sort narrower response if it turns out I can't screw an M7 on the top after all. I was curious how you know so much about the subject, so I put your name into Google and am now going to watch your video on Youtube about early Telefunken distribution.

I found a photo on Blackbird Studio's website showing a CMV5 with a similar head https://www.blackbirdaudiorentals.com/condenser-mics?lightbox=dataItem-jek8fo32

[David Satz]

Well, that extreme elevation of high-frequency response is valid only for more or less direct 0° pickup. Even at 15° the elevation would be considerably less, and because of the capsule's size, its diffuse-field response is closer to being flat. It was designed for placement at a considerable distance from some large body of sound sources (e.g. a full orchestra) in a reverberant space such as a concert hall, where the angles of sound arrival would be close to random (distinctly farther away than conventional practice is today). The idea was to pick up everything with just the one microphone. There would probably still be be a treble rise in the overall pickup, but for the state of AM broadcasting and 78 rpm records at the time, that characteristic could be quite useful--and if not wanted, it could be equalized away to a great extent.

--I looked at the site with the CMV 5 photo on it. There's a lot of basic information that, to put it kindly, they don't seem to have, let's say. But the photos are nice and sharp ...

--The Telefunken talk was just so that I could share the interim results of some research with a group of on-line friends a couple of years ago. It went on far longer than I realized, and the microphone that I was talking into wasn't the microphone that was connected to Zoom, so my voice pickup was unfortunately rather indirect. You'll also see that I made a historical mistake so big that in retrospect, I had to edit a correction in to the video. One of these days I will probably ask to have the video taken down, but in the meantime, there's at least some information in it that I haven't seen elsewhere yet, and if I recall correctly the CM 5 is mentioned briefly. So have fun with it and please don't judge it too harshly.