KM56 project viability

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Potato Cakes

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Hello, everyone. I have been looking at doing a KM56 project for the sole purpose of taking on a new challenge. From doing my initial research, it seems the biggest hurdle to creating anything close to the original is going to be the capsule, which originally was skinned with nickel and apparently prone to being damaged more easily than traditional gold sputtered capsule. I had thought of finding an OEM solution but not exactly sure where to go. I had reached out to some electret manufacturers about a dual capsule options but haven't heard back. I was also wondering about a custom edge terminated capsule but didn't know if that design could be made small enough to fit inside a KM56 sized head basket. I can even go as far as to acquire an original KM56 and dissect it for science, but even after recreating dimensional and mechanical drawings, will it even be worthwhile knowing that there will be an issue trying to find a suitable capsule?

Thanks!

Paul
 
I've also wanted to build a KM56 inspired mic, even going as far as to buy a donor body (maybe a Samson, forget what it is)
But the capsule is the hurdle. Particularly if you want to allow adjustable positions
I had thought of trying to use a Cardiod Gefell capsule as a donor (i.e. M62) but not sure how well this would work, it would be cardiod and it would probably be too expensive.
So I don't know of a good sounding SDC capsule that could be used. I haven't tried any of the recently offered SDCs. Maybe a possibility?
 
Thiersch Elektroakustik Mr. Thiersch is the only one I know of who reskins those capsules. Maybe he also does complete capsules? Other than that I believe that it might be a difficult task since you'd have to have the capsule custom built, it is a unique size afaik.

On 2nd thought: you'd also need a miniature tube like the AC701, which might be kinda unobtainium. If you want to do a real replica it's not gonna be cheap.

Michael
 
Thiersch Elektroakustik Mr. Thiersch is the only one I know of who reskins those capsules. Maybe he also does complete capsules? Other than that I believe that it might be a difficult task since you'd have to have the capsule custom built, it is a unique size afaik.

On 2nd thought: you'd also need a miniature tube like the AC701, which might be kinda unobtainium. If you want to do a real replica it's not gonna be cheap.

Michael
For the AC701, I use the Phaedrus Audio option. I put one in an M49 and was very happy with the results. For the this project the only hurdle for me is the capsule.

Thanks!

Paul
 
Also, Dave Royer has stated in a couple of articles that 5840/6205, when triode-connected, have very similar characteristics to AC701.
 
I've also wanted to build a KM56 inspired mic, even going as far as to buy a donor body (maybe a Samson, forget what it is)
But the capsule is the hurdle. Particularly if you want to allow adjustable positions
I had thought of trying to use a Cardiod Gefell capsule as a donor (i.e. M62) but not sure how well this would work, it would be cardiod and it would probably be too expensive.
So I don't know of a good sounding SDC capsule that could be used. I haven't tried any of the recently offered SDCs. Maybe a possibility?
One of the suggestions that I was given on another thread related just to SDC was to disassemble two electret capsules and fashion some sort of capsule holder to place them in. I'm trying to avoid doing this as I would prefer the capsule construction be handled by someone who already builds them as I would already be spending large amounts of time on the other aspects of the project construction.

Thanks!

Paul
 
Not necessarily trying to create a "clone" per se. I think trying to spend all of the time and money to make a replica of the original nickel plated capsule is a bad idea considering how fragile they were. For me, a scaled down edge terminated capsule akin to a CK12 would make the most sense for this project. But without having a KM56 to measure, I don't know how small it would have to be or even how small can a gold sputtered capsule can made.

I guess the first step is to reach out to various manufacturers and see who would be interested and would have time to make a custom sized capsules.

Thanks!

Paul
 
I don't know of any size restriction on gold sputtering - even these tiny AT capsules are gold.
 

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I think trying to spend all of the time and money to make a replica of the original nickel plated capsule is a bad idea considering how fragile they were.
I managed to kill only one of my probably 5 nickle capsules over the course of maybe 3 decades. It died when it was dropped while powered up. The membrane crashes into the backplate and the shortcut either welds both together or rips a hole into the membrane. Other than that they appear pretty reliable. Not too bad. I admit that I kept my SM 2 out of the possible stick range when used as overhead - and told the drummers that the revenge might be horrible if the hit the mic. ;-)

Michael
 
The ATM 450 reminds me of a cardiod only 56 like microphone by how it is built.
https://www.audio-technica.com/en-us/atm450I have been thinking about building something like the 450 with a little bigger diameter capsule

The 56 has a short distance between the Ni diaphragms.
so
one idea could be two cardiod capsules one on "top" of the other in the opposite direction so the diaphragms are more time aligned
each into a follower then mixed and buffered for the output for the pattern wanted
Or you could build something like the KM86 circuit and the same capsules setup

One thing that I question about the 56 is the solid top of the grill and the base of the capsule mount
 
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