Neumann Vintage U87 Clone : Build Thread.

[joulupukki]

The easiest way is to draw the changes on the D-87 diagram (delete unnecessary components, parts and connections to transform into ORS87)

Should I reference this as the components that would remain in the circuit?

 

[micolas]

Should I reference this as the components that would remain in the circuit?

Logically you should print the schematics of D-87 and ORS87 and put them side by side and analyze the differences, it was stated that ORS87 is a vintage U87 (so D-87) "stripped" of the option to change the polar patterns, of hi -pass and sensitivity reduction pad.
After drawing the changes, then you can easily modify the build. Otherwise it can become a too abstract, mental process for someone who doesn't have much experience.

 

[micolas]

@joulupukki
Do you have the schematic of the D-87?
I put here the scheme of ORS87, (probably with 24v and 33v Zener)

 

[micolas]

@joulupukki
However, I think it would be more correct to start a separate thread called, for example:
"How to convert D-87 to ORS87"
Thus, anyone who built D-87 can help you and increase your chances of success.
Also we must not pollute this thread.

 

[Colorblind]

Just catching up on the last couple years of posts. I built my pair using the SYT-5 bodies, Cinemag transformers and Maiku capsules. Would the Arienne K87 be a significant upgrade? Any better options for those who don't have the scratch for a genuine Neumann K87?

 

[micolas]

Just catching up on the last couple years of posts. I built my pair using the SYT-5 bodies, Cinemag transformers and Maiku capsules. Would the Arienne K87 be a significant upgrade? Any better options for those who don't have the scratch for a genuine Neumann K87?

Maiku K87 are darker capsules, they are rebranded capsules(possibly 3u)
*
The Arienne K87 is a faithful replica of the original, so it would be a significant upgrade. The sound would be closer to the historical original
I recommend it.

 

[theom]

Questions:
1. My green boards U1621 V1.2 have 2 pads marked P/R very close to each other.
Is this phase reverse? for a switch?
Do I bridge the 2 pads if I don't need that?

2. What are the 2 pads marked RT and SW on the same board?

3. On the one board I have the turret for the center FET pin, back side with a wire to G pad on the other board.
on the other board is there another turret that goes on, or do I just terminate the caps per the silkscreen? (without a cap directly soldered to a resistor).


Many Thanks

 

[micolas]

Hi @theom !
The answers to all your questions can be found in this thread. You will have to read it from the beginning.

 

[fsalter]

Questions:
1. My green boards U1621 V1.2 have 2 pads marked P/R very close to each other.
Is this phase reverse? for a switch?
Do I bridge the 2 pads if I don't need that?

2. What are the 2 pads marked RT and SW on the same board?

3. On the one board I have the turret for the center FET pin, back side with a wire to G pad on the other board.
on the other board is there another turret that goes on, or do I just terminate the caps per the silkscreen? (without a cap directly soldered to a resistor).


Many Thanks

Those pads are unused, as are RT and SW.
I just wanted to mention also your R6 (1gig resistor) is soldered backwards. It changes nothing other than it will be more difficult to bias the fet. Not a huge deal though. That also is in the thread.

 

[Khron]

I just wanted to mention also your R6 (1gig resistor) is soldered backwards. It changes nothing other than it will be more difficult to bias the fet. Not a huge deal though. That also is in the thread.

... Because Dany never bothered putting a corrected PCB revision into production(?)

 

[micolas]

... Because Dany never bothered putting a corrected PCB revision into production(?)

...c'est la vie.

 

[Khron]

...c'est la vie.

Yeah, i know it's like that in the vineyard...

 

[micolas]

Yeah, i know it's like that in the vineyard...