Pre Amp Killing Mics?

Snowman999

Snowman999

Active member
I don't know if I've ever asked this before. So, I'm asking -

I have a pre-amp that I love and 2 mics, plus a simple standard mic.

One mic died mysteriously. I used it for a few months, put it aside for over a year and it never worked again. The second mic worked fine and then it also died. I used them both with the same pre-amp.

When the second died, I used the standard mic, and it worked, then didn't work, then worked again. Since this mic didn't need a pre-amp to work properly, I put it in without the pre-amp. It works fine. But, the recording isn't good enough to keep.

Since the other two need a pre-amp, I plugged them into my D1600 which has phantom power, and neither work. But, the standard mic does still work.

Can a pre-amp blow a mic? If not, is there something I can try to get these working? I love both mics, while neither were terribly expensive, I don't want to buy new ones to have the same thing happen.

Thanks.
 
Hi,
Can you tell us the models of the various microphones? I'm not sure what you mean by 'this mic didn't need a preamp' and 'I put it in without the preamp'.
Are your mixing up preamps and phantom power, maybe?

Have you always been using the same cable? Maybe it's damaged, working intermittently?
 
I would surely look into the mic cable first. I recently thought I had a mic go bad. It was just a shitty cable. Mics do not usually just go bad, though it can happen. More likely the cable or the jacks. Test with the least expensive first.
 
The piece I feel is the guilty party is a Tube MP by Art. It's a mic pre-amplifier. I'm recording to Pro Tools 6 with a MBox 2.

The two mics that are dead need a pre-amp to record. The standard mic is a famous one used for live performances. If I could remember (I just looked for it, and can't even find it) you'd know the one I'm talking about. It needs no other power source in order to record.

I used the same cable with all three mics. It only works with the standard. So, it's not the cable. The D1600 phantom power worked fine with the standard mic, while the dead mics still didn't work, it has to be the mics are dead. They've always been put away in their cases after each session, and I've never dropped or abused them. They just stopped working. The only thing they have in common is being plugged into the Art Pre-Amp.

Have you ever heard of a pre-amp blowing out a mic?
 
Yeah, I think you are crossing some terminology here, a little bit.
All of them need a preamp, whereas two of them need phantom power.

Snowman999 said:
I used the same cable with all three mics. It only works with the standard. So, it's not the cable.
Click to expand...
The two microphones which no longer work require phantom power and the dynamic mic does not, which actually adds weight to the idea that the cable could be damaged, I think.

Phantom power is delivered equally via two conductors. If one fails, the mic wont work,
whereas a dynamic microphone may still work, depending on how it's wired.

I've never heard of a preamp damaging a microphone, but I have heard of a shorting XLR cable damaging a preamp.

My recommendation at this stage would be to cease using any of the equipment until you can find another balanced XLR cable to test with,
or can confirm the condition of your present one with a cable tester or multimeter.
 
It's a rarity and in your case it's unlikely. You only need two wires in the Mic cable to be functional for a dynamic to work, but all three wires are needed for a condenser microphone. So my suggestion to you is to replace the Mic cable. They are the cheapest fix and the most common cause of problems like this.
 
Thank you Steenamaroo & Drtechno. I did not know that.

I pass Sam Ash everyday on the way home. I'll be making a pit-stop tomorrow.

THANKS AGAIN! I hope this works. It sounds like it will.
 
No probs. :)
As with anything there could be more to it, but this is definitely the first thing I'd suspect and rule out.
 
I'll just pass in one more scenario where the cable is at fault but the mic might be damaged...

If you plug/unplug a microphone while phantom power is turned on, if the two pins carrying the phantom don't make contact at the same time, it CAN send a jolt of 48 volts on one leg only. It's rare, but this can be enough to damage a mic.
 
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