[winner]

I want to add more modes to U87 based on the directivity schematic of U89. Although they look similar, I’m not sure if this is possible.
This is the schematic I redrawn

[winner]

This is the original U87 schematic

[winner]

This is the original U89 schematic
Thanks everyone for your help

[Khron]

Technically, that's the U87A schematic. But sure, I don't see why not. You'll notice that, despite that they're not used, the bias voltage generator still also contains the parts for the lower voltages as well. All you need is a 5-6 position switch.

[winner]

Technically, that's the U87A schematic. But sure, I don't see why not. You'll notice that, despite that they're not used, the bias voltage generator still also contains the parts for the lower voltages as well. All you need is a 5-6 position switch.

Thank you for your patient answer. In my opinion, the two schematic diagrams have different capsules, and the schematic diagram of U89 has an extra resistor with R1 resistance value of 1G. I don’t understand the connection between them and the working principle , Sorry, I have so many questions

[Khron]

Perhaps you're overthinking this?

What do you like your cymbals to sound like?

Started by Svart Brewery

A Simple Way To Add More Gain To This FET Preamp?

Started by Vikki « 1 2 » The Lab

My head ain't sharp... help with pointing it? DIY Monitor section

Started by jwhmca Drawing Board

UniPhan. Or, easy to add 48V (phantom) to.... almost every possible pre!

Started by Igor The Lab