Topic: High pitched ringing in M-Audio Pulsar ii?

[CrispE]

Howdy all,

I'm in the process of getting into taping shows and putting my first rig together. I recently purchased a stereo set of the Pulsar IIs on ebay after positive comments from this board and others. I'm currently running them into the internal pres of my DR-40, but I keep getting a high frequency ringing coming out of one of the mics, not unlike the ringing in your ears after a gunshot or the like. I've narrowed the problem down to one of the mics by process of elimination and ruled out my cables and the L and R inputs.

I guess my question is what are my options here? Are there any variables I'm leaving out? Would there be any way to mix this out in post? The mics sound surprisingly good minus the incessant ringing.

I got a pretty good deal on the pair, the seller said that he had tested them out a couple times but never used them for any projects, and said they worked well (like new) without any problems. Just hoping I didn't get shafted.

Much thanks for any advice.

(Sorry if this is in the wrong place!)

[Chuck]

Is it like an electronic ringing or mechanical?

Hold the bad mic in your hand while plugged in a pre-amp and listen with headphones. If the ringing stops while you hold it it may be mechanical.

My CAD GXL1200's had a mechanical ringing. The brass tube rang in sympathy with certain notes. I had to dampen them with blue tack (inside) to cure the ringing.

[CrispE]

It seems to be electrical.

I did as you suggested and found that the pitch shifts up and down if I put pressure on one side or the other of the XLRF going into the mic. It seems like it may just have a bad connector? The sound is almost like a constant "mosquito tone" (if you know what I mean), it doesn't ever stop, and the only way to affect it I've found has been with the XLR connection on the mic.

[Chuck]

I suspect grounding. Is there a set screw on the bottom near the XLR connector? Try tightening that up.

[CrispE]

I went to tighten the set screws and found them to be tightened all the way down. However, I think I actually just fixed the problem!

I think one of the pins was slightly bent. I noticed the cable wasn't sitting quite flush on the mic, so I bent it in the correct direction and it seems to have taken care of the ringing!

Thanks for your help Chuck!

[ScoobieKW]

sounds like a loose solder point at the connector.  options are

a. speak to seller about issue, negotiate
b. send to M-Audio for repair
c. independent repair local or otherwise
d. repair yourself.

If it's just a loose join at the connector, any competent electronics tech will be able to fix it for their bench fee.

pay attention to that pin, it could be a problem in the future.

[Chuck]

I went to tighten the set screws and found them to be tightened all the way down. However, I think I actually just fixed the problem!

I think one of the pins was slightly bent. I noticed the cable wasn't sitting quite flush on the mic, so I bent it in the correct direction and it seems to have taken care of the ringing!

Thanks for your help Chuck!

Is that one of the three pins in the XLR connector that are bent?
Those are hard to bend!

[CrispE]

I'm not sure if it was that one of the individual pins was bent or that all three were bent in the same direction slightly. I can't tell now, they all seem straight and the cable sits (basically) flush on the base of the mic.

I've noticed that when I raise my mic stand up pretty high (~8ft) the ringing seems to come back, I'm assuming from the weight of the cable pulling downward on the connection. Nothing a little tape attaching the cable to the stand wouldn't solve, but I would prefer a permanent fix.

Look like I'll probably need to take it to a local tech for repair then?

[Chuck]

A local tech is your best bet if you don't have the experience or tools to open the mic up yourself.
Maybe you can re-coup the cost from the person you bought the mics from. Good luck.

Let us know what happens.

[CrispE]

I contacted the seller and he agreed to refund me $25 to cover the cost of the repair. Also I called down to the local A/V repair and they said they can get it worked out for me.

Thanks for all the help guys!

[Chuck]

Good news.

[CrispE]

Well I took it to a local tech to see what he could do. He looked at all the soldering and the connector and said everything looked intact and that he wouldn't be able to do much for me, then said my best bet would be to send it in to the manufacturer.

I guess I'm going to call M Audio tomorrow and see how much it'll cost me. I got the pair for $140 ($155 but I had a 10% off code). I'm just hoping it won't cost an arm and a leg since I'm not the original owner and have no paperwork. Do you think I should see about getting a second opinion locally before sending them off?

[bugg100]

Have you tested the mic since getting it back from the tech?  I ask because many sdc have screws at the base of the connector/tube junction that are secured when they are UP not DOWN..... The screws tighten into the connector to allow the mic to be disassembled, tube slides off towards the capsule.

The reverse is that the tube slides on and then the screws are raised to secure the tube in place.

Maybe you had a ground issue that was "fixed" when you held pressure, creating ground. If so that may have been repaired just by the tech's reassembly of the mic.

Worth trying out either way before you send the mic off to m-audio