Sound Skulptor forums

Build help and troubleshooting => MP573 Microphone preamplifier => Topic started by: viktor.bom on September 05, 2023, 11:48:32 AM

Title: MP573 - No low end
Post by: viktor.bom on September 05, 2023, 11:48:32 AM

Hello! 

I've had a pair of MP573s for some months now and I love them! They were both working fine for a while but now one of them has lost all its low end. I tried going over the solder points but it didn't change anything. Any recommandations on what to do from here?

Title: Re: MP573 - No low end
Post by: JPK on September 06, 2023, 10:28:16 AM

Can you check the input DC resistance: ohmmeter between pin2 and pin3 of input XLR, power on, Z switch on 1200. Should read about 48 Ohms.
Next check the output DC resistance: ohmmeter between pin2 and pin3 of output XLR, power off. Should read around 42 Ohms.

Title: Re: MP573 - No low end
Post by: viktor.bom on September 07, 2023, 12:44:08 PM

I am getting 50 ohms on the input and 41 ohms on the output

Title: Re: MP573 - No low end
Post by: JPK on September 08, 2023, 10:36:42 AM

These are good.
Check the solder joints of the input transformer pins and of the daughter board to main board connections.
Next try to follow the signal like said here: https://www.soundskulptor.com/forum/index.php?topic=5.msg5#msg5