Weird noises coming through!

David Ennis · August 25th, 2005, 02:35 PM

Just a slight correction on the EDB-1. The two that I have are switchable between 0, -20dB and -40dB.

Audio Technica tech support responded that they have had zero complaints of pin 1 error in the AT3031 over the past five years, but, oddly did not say that that the mic wasn't wired in that manner. I tried one of my own AT3031s, working into my GL2 through a BeachTeck DXA-8, with my Samsung cell phone turned on and sitting in the middle of a small circle created by the the mic, the Beach, the cam and the unbalanced pigtail connecting the Beach to the cam. Full volume on everything. Not a peep in ten minutes. This is all mic level. I was surprised.

[Edit: come to think of it, when I was googling those cell phone detector pens mentioned in this thread, I think the the blurb on one of them named Samsung as one of the ones it wouldn't detect. If so, my test may not be valid. Looking to find that blurb again....]

Sam Gates · August 25th, 2005, 04:12 PM

The pin 1 problems I have seen seldom occur because of the mic unless there is a very strong field very close. IMHO it is usually caused by improper shield grounding in the mixer or mic preamp. Your BeahTeck is an exellent product with tranformer inputs and outputs. It kept the RF from getting into the electronics.

Sam

Jay Massengill · August 26th, 2005, 07:44 AM

I should have mentioned the oddity in the switch labelling and the slim documentation that comes with the EDB-1. They don't specifically mention the built-in 20db pad even with the switch set to "0".
I know I found a reference once on the Whirlwind website that confirmed what I found below on a vendor site but I can't find it now.

"Level Change: -20 dB (input to output, pad switch set to zero dB)
Pad: 3 position, provides 0 dB, -20 dB, -40 dB additional attenuation"

This makes sense if you infer from the instructions that come with it-
"Most instruments will operate properly when set to the "0" position."

That's got to include some attenuation built in.

Other uses for the EDB-1: If you have two of them and the right Y cable you can tie a presenter's laptop headphone output into your sound system over long cables and won't have a ground-loop hum. You know, like when the presenter mentions 5 minutes before the conference that they brought a .wmv file that they need to show to the 300 people in attendence and your mixer is 50 feet away from the podium and he also has to run his own PowerPoint show from the same computer...
You can also use one to create a long direct out from a mixer mic input even if it has the normal interrupting direct outs instead of the Mackie non-interrupting direct outs. I think Fred first did that using the Y feature of the EDB-1 for both the send and receive legs of the line-level direct out signal. This allows you to split off a preamped signal from a mic without the mixer operator otherwise changing the level coming to you. Once the mic trim on the mixer is set, you're good to go. And you're both protected from ground-loop hums.

Jeremy Davidson · August 26th, 2005, 08:22 AM

Fred, try checking your voicemail or making a call. My GSM phone (a Nokia) seems to check for towers about once an hour (if it has good coverage -- maybe more often if it doesn't). Initiating a call will "force" it to transmit RF.

I think the issue is tied more to the technology used (i.e. TDMA vs. GSM) rather than manufacturer. Any idea which one your phone uses? GSM produces short bursts of square waves at roughly 217Hz ('think I found that spec online once). TDMA creates a string of low-frequency pulses.

I know I once picked up a GSM phone on my GL2 (no, not my own phone), but I was not using a balancing converter of any kind, and I think the phone was only about 3' away.

Sam Gates · November 22nd, 2005, 09:05 PM

I don't know if reserecting this old thread is the correct way to go about this but I found this interesting. I have not tried it so I can not promise it works.

http://www.neutrik.com/start.asp

http://www.neutrik.com/images/ock/do..._431221821.pdf

Sam

August 25th, 2005, 02:35 PM	#46
David Ennis Fred Retread Join Date: Jul 2004 Location: Hartford, CT Posts: 1,227	Just a slight correction on the EDB-1. The two that I have are switchable between 0, -20dB and -40dB. Audio Technica tech support responded that they have had zero complaints of pin 1 error in the AT3031 over the past five years, but, oddly did not say that that the mic wasn't wired in that manner. I tried one of my own AT3031s, working into my GL2 through a BeachTeck DXA-8, with my Samsung cell phone turned on and sitting in the middle of a small circle created by the the mic, the Beach, the cam and the unbalanced pigtail connecting the Beach to the cam. Full volume on everything. Not a peep in ten minutes. This is all mic level. I was surprised. [Edit: come to think of it, when I was googling those cell phone detector pens mentioned in this thread, I think the the blurb on one of them named Samsung as one of the ones it wouldn't detect. If so, my test may not be valid. Looking to find that blurb again....] __________________ "Nothing in the world can take the place of persistence..." - Calvin Coolidge "My brain is wired to want to know how other things are wired." - Me

August 26th, 2005, 08:22 AM	#49
Jeremy Davidson Regular Crew Join Date: Aug 2004 Location: Eau Claire, WI Posts: 167	Fred, try checking your voicemail or making a call. My GSM phone (a Nokia) seems to check for towers about once an hour (if it has good coverage -- maybe more often if it doesn't). Initiating a call will "force" it to transmit RF. I think the issue is tied more to the technology used (i.e. TDMA vs. GSM) rather than manufacturer. Any idea which one your phone uses? GSM produces short bursts of square waves at roughly 217Hz ('think I found that spec online once). TDMA creates a string of low-frequency pulses. I know I once picked up a GSM phone on my GL2 (no, not my own phone), but I was not using a balancing converter of any kind, and I think the phone was only about 3' away. __________________ There's no way for you to know if what I'm saying is true unless you know what the truth is, and there's no way for you to know what the truth is unless there is a truth that you can know. -- Frank Peretti

August 25th, 2005, 04:12 PM	#47
Sam Gates Regular Crew Join Date: Jun 2005 Location: Kilgore, TX Posts: 45	The pin 1 problems I have seen seldom occur because of the mic unless there is a very strong field very close. IMHO it is usually caused by improper shield grounding in the mixer or mic preamp. Your BeahTeck is an exellent product with tranformer inputs and outputs. It kept the RF from getting into the electronics. Sam

August 26th, 2005, 07:44 AM	#48
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	I should have mentioned the oddity in the switch labelling and the slim documentation that comes with the EDB-1. They don't specifically mention the built-in 20db pad even with the switch set to "0". I know I found a reference once on the Whirlwind website that confirmed what I found below on a vendor site but I can't find it now. "Level Change: -20 dB (input to output, pad switch set to zero dB) Pad: 3 position, provides 0 dB, -20 dB, -40 dB additional attenuation" This makes sense if you infer from the instructions that come with it- "Most instruments will operate properly when set to the "0" position." That's got to include some attenuation built in. Other uses for the EDB-1: If you have two of them and the right Y cable you can tie a presenter's laptop headphone output into your sound system over long cables and won't have a ground-loop hum. You know, like when the presenter mentions 5 minutes before the conference that they brought a .wmv file that they need to show to the 300 people in attendence and your mixer is 50 feet away from the podium and he also has to run his own PowerPoint show from the same computer... You can also use one to create a long direct out from a mixer mic input even if it has the normal interrupting direct outs instead of the Mackie non-interrupting direct outs. I think Fred first did that using the Y feature of the EDB-1 for both the send and receive legs of the line-level direct out signal. This allows you to split off a preamped signal from a mic without the mixer operator otherwise changing the level coming to you. Once the mic trim on the mixer is set, you're good to go. And you're both protected from ground-loop hums.

November 22nd, 2005, 09:05 PM	#50
Sam Gates Regular Crew Join Date: Jun 2005 Location: Kilgore, TX Posts: 45	I don't know if reserecting this old thread is the correct way to go about this but I found this interesting. I have not tried it so I can not promise it works. http://www.neutrik.com/start.asp http://www.neutrik.com/images/ock/do..._431221821.pdf Sam