M49C circuit details / questions

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The third article is about the creation of the MS2 valve that had to be created especially for the M49/M50 by the small company Hiller in Hamburg, because the big valve-producing companies were unable to fullfil the task at the time.

I hope you find the articles informative or interesting but I´d be happy if they just raise a smile,

Best wishes from Bremen,
Wulf
Really great information in those articles, thank you.
By the way, I own and use a Hiller m69 small membrane microphone with the msc2 tube installed and have a backup tube assembly with another msc2 for that mic and both tubes work still within or close to their specifications, a little noisy for very quite sources but totally usable for something like a strummed acoustic guitar.
70 years after they where built, incredible...
 
Really great information in those articles, thank you.
By the way, I own and use a Hiller m69 small membrane microphone with the msc2 tube installed and have a backup tube assembly with another msc2 for that mic and both tubes work still within or close to their specifications, a little noisy for very quite sources but totally usable for something like a strummed acoustic guitar.
70 years after they where built, incredible...
Really? You do own a Hiller Mik? An even with a spare MSC2? - WOW!!!

... you don´t by any chance have some pics at hand? :)

best wishes from Bremen
Wulf
 
Really? You do own a Hiller Mik? An even with a spare MSC2? - WOW!!!

... you don´t by any chance have some pics at hand? :)

best wishes from Bremen
Wulf
The Mic looks like a typical Hiller miniature mic with the phase ring. Andreas Grosser rescued it and built a fitting power supply with the electronics and a Haufe transformer. The original aluminum membrane was shot, so he had it reskinned from Thiersch with a nickel membrane. So I have no idea if it sounds like it should, but it sounds very nice on transient sources, but is a little light on the bass.
The tube assembly is interesting as it contains the complete electronics in the m69 which is the tube and the grid resistor, as well as the plug and the spring which connects to the capsule. It is a very small microphone indeed :) The assembly seems to be an unused spare and works perfectly. It was a very lucky find on Ebay for 180 Euro....
 

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The Mic looks like a typical Hiller miniature mic with the phase ring. Andreas Grosser rescued it and built a fitting power supply with the electronics and a Haufe transformer. The original aluminum membrane was shot, so he had it reskinned from Thiersch with a nickel membrane. So I have no idea if it sounds like it should, but it sounds very nice on transient sources, but is a little light on the bass.
The tube assembly is interesting as it contains the complete electronics in the m69 which is the tube and the grid resistor, as well as the plug and the spring which connects to the capsule. It is a very small microphone indeed :) The assembly seems to be an unused spare and works perfectly. It was a very lucky find on Ebay for 180 Euro....
A very lucky find indeed! And the 1955 labeled replacement-assembly - wow! - that´s what I call real audio-archaeology. Congratulation!
 
Here’s some pictures of the other part of that Hiller microphone and my schematic of it. The small pencil is just the tube, capsule and a 2G resistor with a quite unique look. This particular microphone is in very good shape, everything original, and it sounds really good. Unfortunately it’s not mine.
IMG_5093.jpegIMG_5098.jpegIMG_5099.jpegIMG_5100.jpegIMG_5101.jpegIMG_5105.jpeg
 
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Hello Tomas,

are you certain about the 2 GOhm Resistor? As far as I know, that one is supposed to be 7 GOhm. Even more unlikely but true. Have a look at the tapatalk-link that Bremusound supplied, you´ll find the original schematics there.

Great pictures by the way, I have never even seen any Hiller mik in my live and so I´m very curious ;)
 
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Among the documents you find at tapatalk, you find a brochure about the company of Albert Hiller, that had been editedin 2000 by the NDR. I took the liberty to translate that brochure into English - here it is. Hope you have as much fun with it, as I had.

best wishes from Bremen,
Wulf
 

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Hello Tomas,

are you certain about the 2 GOhm Resistor? As far as I know, that one is supposed to be 7 GOhm. Even more unlikely but true. Have a look at the tapatalk-link that Bremusound supplied, you´ll find the original schematics there.

Great pictures by the way, I have never even seen any Hiller mik in my live and so I´m very curious ;)
I haven't measured it but for some reason I've written down 2G. The schematics of M59 says 7000Mohm but it does not have the same flat resistor just beneath the contact of the capsule.
 
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