c84 phantom power noise

[dannyofmarge1]

ok, so i just finished up my 4rth pre. my 1st two were c84's and i just finished up two t15's. everything has tested out fine.
but as i was testing the voltages on out the sencond t15 last night, i thought i heard a pop that came from one of the other pres. i got a bit nervous and gave a quick look around, searching for smoke or busted parts. and i didnt notice anything obvious. when i powered up all the pres and tested them, they seemed to be working fine.

so today as i was recording i noticed that after about 10 min one of my c84's started making lots of noise. it seemed like the noise floor jumped up and i started hearing a whole bunch of clicks and pops. i turned the phantom power off and all the noise went away. when i turned the phantom back on, the noise wasn't there but after couple of minutes the noise came back... i need help, any have a suggestions? thanks, Danny

[dannyofmarge1]

any got any suggestions?

[tpryan]

What revision of the C84 do you have?

[dannyofmarge1]

i havent double checked the rev #since i racked it, but im almost positive its 1.9 i didnt buy it more than a month ago.

also, now the sound begins as soon as phantom is applied.

[tpryan]

Can you measure the voltages at R8 and R9 (both ends) and U1, pins 1 through 8 and let us know what you find?