Where to start for an exact accurate version of C800G

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Interesting... I am also in the process of trying to build a replica. I found the Sony capsule for sale but they do not have the transformer for sale or the tubes. The tubes seem possible to source but the transformer might be more difficult, since like the capsule I would assume Sony has a "special" transformer but again thats just an assumption. I have all of the schematics and some have voltages listed. I also have manuals for the mic and power supply which have detailed schematics and a parts list. Id love to see how you accomplish a clone of the C800G. I will definitely follow this thread if anything develops.
 
Judging just by the size of the original transformer i would bet it was designed to be ultra transparent. Which makes things easier, as vintage "vibey" are tough to replicate, this one should be easier. But i am just guessing.
 
kingkorg said:
Judging just by the size of the original transformer i would bet it was designed to be ultra transparent. Which makes things easier, as vintage "vibey" are tough to replicate, this one should be easier. But i am just guessing.

6:1 ratio
 
built a moded quite a few..

Just use k67 Neumann in this. a lot of the sound of this mic is the long body Russian 6au6a at 5.7v and the coupling cap.
Why do you say this? I know they are the same type of capsule.. but what would make the Neumann a stronger choice , or what would make the Sony capsule a stronger choice?
 
Interesting... I am also in the process of trying to build a replica. I found the Sony capsule for sale but they do not have the transformer for sale or the tubes. The tubes seem possible to source but the transformer might be more difficult, since like the capsule I would assume Sony has a "special" transformer but again thats just an assumption. I have all of the schematics and some have voltages listed. I also have manuals for the mic and power supply which have detailed schematics and a parts list. Id love to see how you accomplish a clone of the C800G. I will definitely follow this thread if anything develops.
did you ever end up doing a build?
 
Literally identical? Not possible as you'd need to nail the body (grille, body tube, cooler), capsule, tube, etc. But similar? You could buy a replacement capsule from Sony if they still sell them, get a mostly similar tube, make a similar circuit, etc.
 
Is the goal to only get a C800G at a cheaper price point? Or is it to build a C800G and learn along the way. If you're hoping to learn about mics, I'd recommend sourcing the C800G capsule and then building another circuit. Build a G7, M49, U47, etc. Get a quality capsule for the mic you build (Beesneez, Tim Campbell, 3U, Heisermann, etc) and swap it with the C800G capsule. Once you have done this, work on building the C800G body and sourcing other components. Knowing how circuit, component, and body differences change the sound will help you make an educated decision on cutting corners or sourcing components like the transformer.
 
The original image doesn't have value the transformer and resistor ratio P103 as shown in your image.
I think someone arbitrarily wrote these values ..
 

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Scheme from the service manual, even there the ratio of the transformer is not indicated ..
 

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This can only be seen in an article in some Japanese publication .. (on the image).
 

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The ratio is almost irrelevant. The point with that transformer in that mic is to be as transparent as possible. I't doesn't color the sound. It's not u67, u47...
Choose transformer for widest bandwidth, lowest phase shift, and lowest thd down to the lowest frequencies. A lot of modern ones will do.

The point of that text and whole mic is demonstration of Japanese superioriority in technical sense over other microphones at the time.
 
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The ratio is almost irrelevant. The point with that transformer in that mic is to be as transparent as possible. I't doesn't color the sound.
In the available sources of technical documentation for the c-800g, I have not read anything like this anywhere.

Where can I see/read the source of this information?
 
I can't bother (sorry) to go through all the documentation i've gathered on it, although i'm right now in the process of cloning a c800.

https://groupdiy.com/threads/sony-c800-inspired-body.81262/
It has been reported during the years the c800 is designed for best possible technical performance, hence the cooling device as well. It is obvious just by looking at the size of it the imperative was transparency, bandwidth... that thing is squeaky clean. Rather high anode voltage - headroom, transformer has to be able to cope with the levels.

This is a nice summary on c800.

http://www.foxaudioresearch.ca/c800clone.htm
Maybe @Moby has more details on the specs.
 
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I disagree with a few things in the fox C800G article

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This microphone does cost more than a lot of other microphones so why not do different things with the design of a tube microphone

Nothing wrong with a 6au6 Schoeps used in a microphone. A pentode as a triode is nothing special in a tube microphone.

The lower resistance divider is a good thing. Something to know about about series vs shunt regulation, loading a series regulator can make it work a little more like a shunt regulator.

Tube rectifiers can have smoother turn on and off

The cooling helps with gas in the tube
 
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