ME66/K6 hums at DVinfo.net

Valeriu Campan · September 3rd, 2004, 09:32 PM

My Me66/K6 mike came back from a shoot recently. During some tidy-up session and re-testing, I found an intermitent hum that is sometimes present, depending on the position of the mike. I tried various leads (no difference) and also discovered that touching the mike will decrease or cancel the hum.
Any ideas and solutions?
Thanks in advance

Bryan Beasleigh · September 3rd, 2004, 09:56 PM

What camera and how is the ME66/K6 connected? How long is the run?

Valeriu Campan · September 3rd, 2004, 10:13 PM

I connected directly to the camera(s) XL1 and Sony DSR570 with the 1.5V battery and with PhantomPower from camera swithced on. I tried 3 leads, two 8 meters and a short .5m one. Also I tried with the field Shure mixer with phantom power activated and got the same results. When touching the mike, the noise is amost gone.
Hmmmmmm

Jay Massengill · September 4th, 2004, 07:33 AM

Are both cameras running off battery power or an AC adapter of some kind? Do you have anything else connected to the camera, like a video monitor, that is running on AC power? Does your XL1 use an XLR adapter or are you converting to unbalanced with a simple adapter?
I would clean the battery contacts inside the mic with a soft clean cloth. Switch the power switch several times while the battery is out and the mic is disconnected. Replace the battery with a new one and clean the contacts on the battery too before you install it. Make sure the mic capsule and body threads are snug. Flick the bass rolloff switch several times. Let the mic stay inside with the airconditioning to dry out if condensation or moisture might be the culprit. After all this test it with the DSR570 running on batteries and nothing else connected. Check it first with the mic battery powering the mic, then turn everything off and switch the phantom on the camera on and power up. Are you using StarQuad type mic cables and are you in a location that may have a strong source of electrical interference? Let us know the results.

Matt Gettemeier · September 4th, 2004, 08:11 AM

I'm wondering if there's a problem with the XLRs... since you said you tried 3 different ones I was hesitant to mention this... but you know how an XLR works right? Two opposite phase leads and a ground. Sounds like the adapter is changing the ground... or maybe the ground of the XLR isn't connected at one end... By your discription I'd guess a grounding problem one way or another. Shure makes some adapters to change the configuration/phase of the 3 pin system of an XLR... they can be real problem solvers.

Sorry this probably doesn't help much. I'd certainly try everything Jay just recommended.

Jay Massengill · September 4th, 2004, 10:33 AM

Good point Matte, I'd check the wiring of your XLR cables just in case they were from the same maker and had an odd or incorrect wiring scheme that's contributing to the problem. I doubt that's it, but you never know till you check. It's easy to do with a simple multitester that's available for less than $10. Use something to hold the female end of the cable so that one of the probes can hang snugly in each hole by its own weight. This leaves both hands free to test with the other probe on the male end of the cable.
Most connectors have the pin numbers molded into the plastic, but they can be very small.
Pin 1 should only have a connection to Pin 1 and the other 2 pins should match each other as well and not have any connection to anything else.
Also check that the outer casing of each connector has NO connection with any of the pins or the other casing.
You can check for intermittent problems more easily if you have a Behringer or Ebtech tester that can latch onto an intermittent connection. These cost between $40 and $60 but are very handy and have a tone generator too.

Valeriu Campan · September 9th, 2004, 02:09 AM

Thanks guys for your replies. The cables I am using are different brands and lenghts. I opened the casing and re-closed it, tightened it and voila! The hum's gone. I tested it with a Shure field mixer (phantom power on), but this was used as well in my previous permutations. I'll keep an ear on it in the future.
Thanks again,
Valeriu

September 3rd, 2004, 09:32 PM	#1
Valeriu Campan Major Player Join Date: Mar 2004 Location: Melbourne, Australia Posts: 223	ME66/K6 hums My Me66/K6 mike came back from a shoot recently. During some tidy-up session and re-testing, I found an intermitent hum that is sometimes present, depending on the position of the mike. I tried various leads (no difference) and also discovered that touching the mike will decrease or cancel the hum. Any ideas and solutions? Thanks in advance __________________ Valeriu Campan

September 3rd, 2004, 09:56 PM	#2
Bryan Beasleigh Trustee Join Date: May 2002 Location: Barrie, Ontario, Canada Posts: 1,922	What camera and how is the ME66/K6 connected? How long is the run? __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ".......holy smokin rubber lips...what a ride!"

September 3rd, 2004, 10:13 PM	#3
Valeriu Campan Major Player Join Date: Mar 2004 Location: Melbourne, Australia Posts: 223	Hmmmm I connected directly to the camera(s) XL1 and Sony DSR570 with the 1.5V battery and with PhantomPower from camera swithced on. I tried 3 leads, two 8 meters and a short .5m one. Also I tried with the field Shure mixer with phantom power activated and got the same results. When touching the mike, the noise is amost gone. Hmmmmmm

September 4th, 2004, 07:33 AM	#4
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Are both cameras running off battery power or an AC adapter of some kind? Do you have anything else connected to the camera, like a video monitor, that is running on AC power? Does your XL1 use an XLR adapter or are you converting to unbalanced with a simple adapter? I would clean the battery contacts inside the mic with a soft clean cloth. Switch the power switch several times while the battery is out and the mic is disconnected. Replace the battery with a new one and clean the contacts on the battery too before you install it. Make sure the mic capsule and body threads are snug. Flick the bass rolloff switch several times. Let the mic stay inside with the airconditioning to dry out if condensation or moisture might be the culprit. After all this test it with the DSR570 running on batteries and nothing else connected. Check it first with the mic battery powering the mic, then turn everything off and switch the phantom on the camera on and power up. Are you using StarQuad type mic cables and are you in a location that may have a strong source of electrical interference? Let us know the results.

September 4th, 2004, 08:11 AM	#5
Matt Gettemeier Major Player Join Date: May 2003 Location: St. Louis, Missouri Posts: 936	I'm wondering if there's a problem with the XLRs... since you said you tried 3 different ones I was hesitant to mention this... but you know how an XLR works right? Two opposite phase leads and a ground. Sounds like the adapter is changing the ground... or maybe the ground of the XLR isn't connected at one end... By your discription I'd guess a grounding problem one way or another. Shure makes some adapters to change the configuration/phase of the 3 pin system of an XLR... they can be real problem solvers. Sorry this probably doesn't help much. I'd certainly try everything Jay just recommended.

September 4th, 2004, 10:33 AM	#6
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Good point Matte, I'd check the wiring of your XLR cables just in case they were from the same maker and had an odd or incorrect wiring scheme that's contributing to the problem. I doubt that's it, but you never know till you check. It's easy to do with a simple multitester that's available for less than $10. Use something to hold the female end of the cable so that one of the probes can hang snugly in each hole by its own weight. This leaves both hands free to test with the other probe on the male end of the cable. Most connectors have the pin numbers molded into the plastic, but they can be very small. Pin 1 should only have a connection to Pin 1 and the other 2 pins should match each other as well and not have any connection to anything else. Also check that the outer casing of each connector has NO connection with any of the pins or the other casing. You can check for intermittent problems more easily if you have a Behringer or Ebtech tester that can latch onto an intermittent connection. These cost between $40 and $60 but are very handy and have a tone generator too.

September 9th, 2004, 02:09 AM	#7
Valeriu Campan Major Player Join Date: Mar 2004 Location: Melbourne, Australia Posts: 223	Thanks guys for your replies. The cables I am using are different brands and lenghts. I opened the casing and re-closed it, tightened it and voila! The hum's gone. I tested it with a Shure field mixer (phantom power on), but this was used as well in my previous permutations. I'll keep an ear on it in the future. Thanks again, Valeriu