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R/E/P => Klaus Heyne's Mic Lab => Topic started by: U47miked on June 12, 2022, 08:35:06 AM

Title: Neumann TM253 Microphone: Does Anybody know About This Obscure Creature?
Post by: U47miked on June 12, 2022, 08:35:06 AM
I am trying to locate any info about Neumann TM253 (yes, I mean T, not K) microphone and there are no results. Even Andreas Grosser never heard about such a microphone. This seems to be any short line of measurement version of KM253. Any tip would be appreciated. I have two versions of this microphone with very low serial numbers, one is TM253 and second TM253c. Based on AC701k, it had to run with its special PSU as usual AC701k mic PSU N52 would need not drive it until the mic is not slightly modified. Thank you.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: klaus on June 12, 2022, 01:23:23 PM
Two things that could move this froward:

1. Post a few close-ups, including the mic connector

2. Post any information you have found, as you seem to have found something somewhere ("This seems to be any short line of measurement version of 
    KM253.")
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: David Satz on June 25, 2022, 08:16:59 PM
The microphones with three-digit numbers starting with a "2" were versions with large, "RF-proof" Tuchel output connectors, something that German broadcasters sometimes required (e.g. when their recording studios and their transmitters were in the same building, and RF levels in the studio were quite high).

But the "TM" in the name is something I've never heard of, and as I'm sure you know, it's not listed in Neumann's own listing of their historical microphone types. It's not a measurement microphone; those had "MM" in their names.

[edited later to add:] Whoops, the "base model" TM 53 is indeed listed, so the 253 is logically a version with the large "RF-proof" Tuchel connector mentioned above. See message from Martin Schneider below.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: klaus on June 26, 2022, 12:35:27 PM
The microphones with three-digit numbers starting with a "2" were versions with large, "RF-proof" Tuchel output connectors
To address David's usually hyper-correct use of the English language when applied to microphone-related subjects:
The broadcast Tuchel connector is generally not referred to as "large"- that moniker is reserved for the truly large M49 and U47 Tuchels.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: David Satz on June 27, 2022, 09:58:22 AM
Call it what you like; the connectors are large compared to the usual small Tuchel or XLR connectors, is all I meant. See attached photos of the KM 253, 254 and 256 for example.

I'll be very interested to find out what these microphones are, in any event.

--best regards
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: klaus on June 27, 2022, 12:15:14 PM
..and talk about esthetic beauty: especially the one on the left - stunning!
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: Vertigorecording on June 27, 2022, 06:15:11 PM
The grille always reminds me of a helmet that might be worn by a gargoyle or guardian carved into Notre Dame.  :)
-Charlie Bolois
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 28, 2022, 05:07:57 PM
Thanks for your feedback and I am sorry it took me a while to get the pictures. I needed to pick the mics from a tech.
Here are the pictures of TM253c, serial number 017. Connector is the same as other KM253/KM254 series. Pattern is omni.
Tube is Telefunken AC701k.

Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 28, 2022, 05:10:51 PM
This is a serious limitation of attachment file size, so I needed to make resolution lower and send a couple of pics.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 28, 2022, 05:11:42 PM
Capsule
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 28, 2022, 05:12:08 PM
Electronics with tube.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 28, 2022, 05:13:18 PM
Was missing, sorry
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 28, 2022, 05:14:07 PM
Electronics again.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: klaus on July 28, 2022, 09:05:38 PM
Looks very much like a Neumann calibration mic based on the (stock) KM53 amplifier with very small (most likely, aluminum) capsule.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 29, 2022, 02:26:10 AM
Yes, indeed. The capsule looks aluminium like KM253. And two other mics have this focusing ring placed on the capsule, so I can see diameter of diaphragm is actually the same as KM53/KM253.

Do you know maybe if Martin Schneider is still at Neumann to ask for what reason they did such microphones?
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: klaus on July 29, 2022, 12:55:26 PM
Yes, Martin is still in charge of microphone R+D at Neumann in Berlin.
You can contact him: schneidm at neumann.com
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on July 29, 2022, 03:59:56 PM
Thank you very much.
With analog Regards
Wojcek Czern
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: Kai on July 29, 2022, 07:22:57 PM
Probably a capsule intended für measurements.

The front cylinder’s diameter is exactly 1/2 inch I guess?!
That’s the norm size for use with a calibrator.
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: schneidm on August 14, 2022, 06:24:22 AM
Hello,
just happened to see this post by chance.

TM stands for "tele-microphone", a designation for the early Sennheiser shotgun microphones, in the late 1950s / early 1960s. A small number of TM53 were shipped to Sennheiser, then still named "Labor Wedemark" in the late 1950s. Intended for a condenser version of the otherwise dynamic Sennheiser shotgun mics. A very small number of TM253 (with RF proof connectors) was shipped to a German broadcaster in 1963/1964.
The TM53 capsule was built for a polarization voltage of 200V, so it's not a standard KM53 capsule. Lower voltage will yield less sensitivity, thus higher equivalent self noise.

The TM53 is listed in our "Overview of microphones and capsules".
https://en-de.neumann.com/product_files/8912/download

Best regards,

Martin Schneider
Title: Re: Neumann TM253 microphone does anyody know this obscure creature?
Post by: U47miked on August 14, 2022, 07:03:37 AM
Hello, thanks for your unfailing - as always - input. That clears a lot. Do you know if any schematic of this microphone survived? And what kind of PSU was intended to use with TM253? We realized that using of standard N52 PSU for AC701k tube needs small modification of the TM253 microphone. It is unbelieveable how prolific Neumann team used to be and how many designs were being made in golden era of microphone discoveries.
With analog Regards
Wojcek Czern