EZ 1073 P48 clicking-noise issue - solved

[jafo]

Hello,

I am Jan, this is my first post, so hello to everybody.

I've built an AML EZ 1073. It was fun and thanks to the color book assembling was fast an easy.
It works and sounds really nice but I have an issue with phantom power.
When I connect a condenser mic and turn on phantom power there is a clicking noise.
It's quiet. With gain and trim both turned up to maximum the click-peaks are around -50dB in Pro Tools.
The clicks appear every 0.096 seconds. Under "normal" conditions,  i.e. u87 with 40dB gain for VO-work,
the recorded voice is not really affected. But when I want to add some color by turning up gain & trimming the output
and then compress and/or limit it for commercial stuff, the clicks come up.

This is a sound clip ( full gain at EZ an boosted 36dB with clip gain in PT to hear it well)
https://www.dropbox.com/s/je5g6egd9gdneyq/click.wav?dl=0

I've attached a snapshot and would be very thankful if somebody can give me an advice where these clicks come from or what I can check.

Thanks in advance!
Jan

 

[pvision]

Have you tried it with a different condenser mic?  What phantom voltage do you get on the XLR? Do you get the clicking when a dynamic is connected with the phantom on?

If you have access to an oscilloscope I'd suggest checking the phantom output for clicks on the 48 Volts. If it's there, or if there is a cyclical peak at the appropriate rate, I'd go further back in the phantom power supply chain to see where it originates

If it only occurs with the phantom on, logically it's caused by the phantom and is either causing the noise to be generated in the mic or causing it to be generated in the preamp. If the noise is heard with the phantom on and no mic connected, likely it's the latter

Nick Froome

 

[jafo]

Hi Nick,

thank you for your answer. I recorded with the Neumann this morning through  my interface-preamps and everything was fine,
so I thought it could not be the mic. I tested a Rode and the clicks disappeared! While switching the two mics back an forth I realized the the bottom  screw cap of the Neuman was a little loose - I tightened it and the clicking disappeared!

Can't believe that this can cause such a phenomena. I recorded and measured the clicks three times - every time 0.096 second distance between peaks and the same level! ???

Anyway, problem solved, thank you!

Jan