Sound Skulptor forums

Build help and troubleshooting => MP566 Tube microphone preamplifier => Topic started by: ellendelen on January 19, 2022, 07:43:36 PM

Title: 48v Not Working
Post by: ellendelen on January 19, 2022, 07:43:36 PM

Hi, I have been testing my new preamp which sounds lovely! I have never heard a SM57 sound this fat! 

The only thing that doesn't seem to work is the 48v. Any tips on what to check?

Title: Re: 48v Not Working
Post by: JPK on January 20, 2022, 09:46:48 AM

The 48V circuit is very straightforward:
It goes from the back connector (lower finger) to switch SW1 to the input XLR through R1, R2, R3.
Check the solder joints on these components.

Title: Re: 48v Not Working
Post by: ellendelen on January 20, 2022, 12:33:45 PM

It turns out it is across all of my modules. Weird, I didn't have this before.

Engaging phantom power only puts out about 8 volts DC. So I guess that its something faulty in my RND R6. I will check it with them. 

Thanks!