1

MP599 Microphone preamplifier / Re: MP599 preamp phantom problem

« on: January 27, 2024, 05:27:07 PM »

I just checked the voltage and it is like this:
L           R
0.07 R3 0.06
0.00 R4 0.06

Is this the information you asked?

2

MP599 Microphone preamplifier / Re: MP599 preamp phantom problem

« on: January 17, 2024, 03:34:11 PM »

Hello again!
I checked out R3 and R4 I found that R4 is burnt. Should I replace it? Should it be 680 ohms as in the photo attached? Should I buy it somewhere nearby or can you send me one?

Thank you!!

3

MP599 Microphone preamplifier / Re: MP599 preamp phantom problem

« on: January 04, 2024, 10:41:15 PM »

Hello JPK, I just Checked the solder joints of SW1, R1, R2, R3, R4, C3, C4 and they are fine. I have measured the phantom voltage on the mic XLR and it is just 2 volts. 
What can I do next?

Thank you very much in advance!

4

MP599 Microphone preamplifier / MP599 preamp phantom problem

« on: January 02, 2024, 02:19:55 PM »

Hello! I purchased and assembled two MP599 Microphone preamplifiers 4 years ago. I always used the preamps to amplify a synth. Now I was trying to amplify some condenser microphones and I realized that one works fine but the other has a problem with phantom. Both preamps work fine with a dynamic microphone such as Shure sm 58, but only one of them works with the condenser microphone. I guess the problem is something related to phantom. How can I fix this? Thank you very much in advance!!