mic pre pops on turn on/off

Hey all;

I use a homebrew mic pre that sounds great. Problem is, when I turn it on or off, I get a pop. The same happens when I turn on or off phantom power. The pop isn’t really loud, so I’m not as worried about damage to my speakers as I am to my soundcard. When n is open, it clips on the record VU meter. I measured the output with a scope, and it appears to be around 1 volt or so (so I wouldn’t think that would be too high a peak). I have also considered building a slow turn on circuit, but that won’t help the phantom power situation or the pops at turn off.

Do any of you have the same problem with your micpres? Is this something I should worry about?

Thanks

Powering up my preamps, compressors, effects , mixing boards and audiointerface give me a pop. I think they tend to do that.

Turning on the phantom power gives somewhat lesser signal, on my mackie board virtually not at all, behringer gves some more but not too much.

I don’t think there’s need to worry…

Um, yeah, that is what they do. That is nothing abnormal. What is abnormal is that you leave your speakers/amplifier on to take the pop. Never ever ever ever ever ever turn phantom power on/off, connect/disconnect a mic, or turn a preamp/mixer on/off with out first turning off the amplifier connected to the speakers. You are just going to blow out your voice coils in your speakers.

Yup - poweramp should be last on, first off.

In this case though, you want to mute the input channel going into the comp. That’ll stop anything further on seeing the spike.

-Dan

Like I said, I’m not too worried about the speakers (the amp is usually off when I power things up), I’m more worried about that spike slamming the inputs of my soundcard. Do you think this is a problem?
Thanksd

The pops are unlikely to damage the soundcard unless they are significantly more than the 1 volt you measured. More like 10V or more before you need to worry. Good audio recording cards should have some protection on the inputs that absorbs big spike without damage. The software VU meters will show clipping, but the A/D converters on the card don’t get blasted. Can’t say how it is for consumer type cards…

Matt.

The pops are unlikely to damage the soundcard unless they are significantly more than the 1 volt you measured. More like 10V or more before you need to worry. Good audio recording cards should have some protection on the inputs that absorbs big spike without damage. The software VU meters will show clipping, but the A/D converters on the card don’t get blasted. Can’t say how it is for consumer type cards - more susceptible to big spikes, but unlikely to be damaged by a few volts.

Matt.