Sound Skulptor forums

Build help and troubleshooting => MP566-II Tube microphone preamplifier with HPF => Topic started by: spurton@gmail.com on May 07, 2026, 09:10:04 PM

Title: Possible ICs fried MP566-II
Post by: spurton@gmail.com on May 07, 2026, 09:10:04 PM
I recently built the MP566-II Tube pre and when I first powered it on I could not get any sound out of it. So I removed it and discovered I had a solder bridge on the back of the header pins to the tube PCB. I fixed the bridge and ran it again. It puts out sound but very quiet, not enough to register signal but I can hear it faintly. It also distorts heavily when I turn up the gain knob or output knob. I know shorting leads can fry the ICs. Does this sound like what I did? If so I will order new ones. Thank you. 
Title: Re: Possible ICs fried MP566-II
Post by: JPK on May 08, 2026, 08:46:01 AM
Can you tell me which pins were shorted?
What results do you get from the voltages checks in the test guide steps 2 to 5?