Does anyone have a (readable) Schoeps CMC4 schematic?

[HalfNote5]

Hi everyone! Thanks in advance for your assistance. Does anybody here have a schematic for the Schoeps CMC4?
I found one but it's so reduced in size and pixellated as to be unable to read.

Thanks!

 

[OneRoomStudio]

https://groupdiy.com/threads/schoeps.66086/

 

[HalfNote5]

https://groupdiy.com/threads/schoeps.66086/

Thanks so much!! ^_^

Followup question: Anyone know the inductor values marked at Dr1/Dr2? Unless I'm blind, they're not listed on the schematic.

 

[Khron]

Followup question: Anyone know the inductor values marked at Dr1/Dr2? Unless I'm blind, they're not listed on the schematic.

Not super critical, 22-47uH should be plenty.

 

[HalfNote5]

Not super critical, 22-47uH should be plenty.

Thanks very much! ^_^

 

[rogs]

This version of the CMC5 circuit....



.... has different idents for the various inductors.

In the original schematic, the voltage multiplier oscillator (T2) includes an unspecified transformer marked TR1.
This is replaced with two unspecified inductors, DR1 and DR2 in this new version. These are typically within the range 47uH - 150uH, with DR1 being around twice the value of DR2..... These will need to be mounted close to each other, to allow for some magnetic coupling.

In this newer schematic the output series inductors are marked DR3 and DR4, and - as Khron has already described - the values are not critical.

 

[HalfNote5]

This version of the CMC5 circuit....

View attachment 147277

.... has different idents for the various inductors.

In the original schematic, the voltage multiplier oscillator (T2) includes an unspecified transformer marked TR1.
This is replaced with two unspecified inductors, DR1 and DR2 in this new version. These are typically within the range 47uH - 150uH, with DR1 being around twice the value of DR2..... These will need to be mounted close to each other, to allow for some magnetic coupling.

In this newer schematic the output series inductors are marked DR3 and DR4, and - as Khron has already described - the values are not critical.

Thanks! So just ensure the value of DR1 is double DR2, and the specifics, as long as they're withing tolerances, are non-critical?
I really appreciate the insight.

I might could use a 2:1 transformer then?

 

[micolas]

Thanks! So just ensure the value of DR1 is double DR2, and the specifics, as long as they're withing tolerances, are non-critical?
I really appreciate the insight.

I might could use a 2:1 transformer then?

You can, provided the inductances are in the range of tens/hundreds of uH
Neumann used an auto-transformer for U87ai DC/DC converter
Edit:
it is much easier, cheaper and miniature with low current inductors.

 

[rogs]

Thanks! So just ensure the value of DR1 is double DR2, and the specifics, as long as they're withing tolerances, are non-critical?
I really appreciate the insight.

I might could use a 2:1 transformer then?

As micolas says, it's easier to use miniature low current inductors.

The attached image shows my own version of a Hartley oscillator based voltage mulipplier, together with a photo of the stripboard layout I used, to give you an idea of the relative inductor positions......

 

[micolas]

Here is my dc/dc version, built point-to-point

 

[HalfNote5]

This version of the CMC5 circuit....

View attachment 147277

.... has different idents for the various inductors.

In the original schematic, the voltage multiplier oscillator (T2) includes an unspecified transformer marked TR1.
This is replaced with two unspecified inductors, DR1 and DR2 in this new version. These are typically within the range 47uH - 150uH, with DR1 being around twice the value of DR2..... These will need to be mounted close to each other, to allow for some magnetic coupling.

In this newer schematic the output series inductors are marked DR3 and DR4, and - as Khron has already described - the values are not critical.

Thanks!! This seems like it might be an easier build to work with, from a tinkering perspective. Not least because as it's inside a pencil mic, a transformer's harder to fit. I'm experimenting with trying to get it largely down to SMT components except for some through-holes I wanna tinker with the values on. (a couple different FETs and capacitor values.)