That one is much better apart from the Zener value which can be chosen. Somebody is paying attention.
I'm going to bed.
Koz
USB pre-amp with direct monitor for electret microphone
Forum rules
This forum is for Audacity on Windows.
Please state which version of Windows you are using,
and the exact three-section version number of Audacity from "Help menu > About Audacity".
Audacity 1.2.x and 1.3.x are obsolete and no longer supported. If you still have those versions, please upgrade at https://www.audacityteam.org/download/.
The old forums for those versions are now closed, but you can still read the archives of the 1.2.x and 1.3.x forums.
Please state which version of Windows you are using,
and the exact three-section version number of Audacity from "Help menu > About Audacity".
Audacity 1.2.x and 1.3.x are obsolete and no longer supported. If you still have those versions, please upgrade at https://www.audacityteam.org/download/.
The old forums for those versions are now closed, but you can still read the archives of the 1.2.x and 1.3.x forums.
-
kozikowski
- Forum Staff
- Posts: 68942
- Joined: Thu Aug 02, 2007 5:57 pm
- Operating System: macOS 10.13 High Sierra
Re: USB pre-amp with direct monitor for electret microphone
In stead of a battery box, I use a phantom-to-pip adapter. Here's the schematic:

You could use a 9V zener (D1) to lower the output to less than 10V if you think your mic wouldn't be able to withstand 12V.
The lowest noise is produced with a 5.6V zener.
Higher pip power gives a higher headroom. The output won't be significantly higher, and the noise floor is a tiny bit lower with a higher voltage to the electret.
You could use a 9V zener (D1) to lower the output to less than 10V if you think your mic wouldn't be able to withstand 12V.
The lowest noise is produced with a 5.6V zener.
Higher pip power gives a higher headroom. The output won't be significantly higher, and the noise floor is a tiny bit lower with a higher voltage to the electret.
-
kozikowski
- Forum Staff
- Posts: 68942
- Joined: Thu Aug 02, 2007 5:57 pm
- Operating System: macOS 10.13 High Sierra
Re: USB pre-amp with direct monitor for electret microphone
And again, we're designing a Phantom Power adapter. My original design was to a dry (no battery) 1/8" plug, not commercial grade XLR. There was no 48v and no other option.
Koz
Koz