I'm told by Canon I need to use 600 ohm mic at DVinfo.net

Bryan Coleman · May 28th, 2002, 09:46 PM

Canon tells me I need to use a 600 ohm mic. I came to this message board looking for some mics I should consider getting. But I'm not so sure that the mics listed here are 600 ohms. One earlier thread talked about an ECM-55b. I don't believe that is 600 ohms. I'm using a ECM-66b...and have experienced a hum with it. Can someone list me a few professional models to look at?

Thanks in advance........
jal_3@hotmail.com

Don Palomaki · May 29th, 2002, 02:53 PM

The mic input impedance is 600ohms. For best results the mic shoud be deistgned to work into a 600 ohm load. These often have impedances ranging from 100 to 600 ohms, and most professional mics will fall into this category. The ECM55b should be fine, so should the ECM66b. THeyboth ahve output impedance on the order of 100 ohms

Both are balanced output. If you did not use a balanced-to-unbalanced matching transformer, you could pickup hum.

Bryan Coleman · May 30th, 2002, 03:58 PM

Audio has always been my Acheles Heel....So the mic has a "range" as far as its impedence? I hate to say it...but this is all new to me.
Thanks again for the clearification.

Don Palomaki · June 1st, 2002, 05:55 AM

Each mic has a specific characteristic impedance. Some offere a selection from two or more specific impedances (typically by changing taps on an internal transformer). However, any given mic can successfully drive a preamplifier over a wide range of input impedances.

The trick is that the input impeance of the preamplifier should be equal to or higher than the output impedance of the mic.

In some cases you will see a mic with a characteristic output impedance of , say 250 ohms and a recommendation that it be used with preamps that have a input impedance of say 600 ohms or higher.

One thing people sometimes do is use a "Y" adapter to feed one mic into two channels of the XL1 (or other device). The XL1 has a input impedance of 600 ohms. They "Y" adapter efffectively parallels the input impedance, so the mic sees 300 ohms. This might present a problem for some mics - and it may appear as distortion at lower sound levels.

May 28th, 2002, 09:46 PM	#1
Bryan Coleman Regular Crew Join Date: May 2002 Location: santa cruz CA Posts: 47	I'm told by Canon I need to use 600 ohm mic Canon tells me I need to use a 600 ohm mic. I came to this message board looking for some mics I should consider getting. But I'm not so sure that the mics listed here are 600 ohms. One earlier thread talked about an ECM-55b. I don't believe that is 600 ohms. I'm using a ECM-66b...and have experienced a hum with it. Can someone list me a few professional models to look at? Thanks in advance........ jal_3@hotmail.com __________________ Bryan Coleman Santa Cruz CA

May 30th, 2002, 03:58 PM	#3
Bryan Coleman Regular Crew Join Date: May 2002 Location: santa cruz CA Posts: 47	Thanks for the reply Don Audio has always been my Acheles Heel....So the mic has a "range" as far as its impedence? I hate to say it...but this is all new to me. Thanks again for the clearification. __________________ Bryan Coleman Santa Cruz CA

May 29th, 2002, 02:53 PM	#2
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,489	The mic input impedance is 600ohms. For best results the mic shoud be deistgned to work into a 600 ohm load. These often have impedances ranging from 100 to 600 ohms, and most professional mics will fall into this category. The ECM55b should be fine, so should the ECM66b. THeyboth ahve output impedance on the order of 100 ohms Both are balanced output. If you did not use a balanced-to-unbalanced matching transformer, you could pickup hum.

June 1st, 2002, 05:55 AM	#4
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,489	Each mic has a specific characteristic impedance. Some offere a selection from two or more specific impedances (typically by changing taps on an internal transformer). However, any given mic can successfully drive a preamplifier over a wide range of input impedances. The trick is that the input impeance of the preamplifier should be equal to or higher than the output impedance of the mic. In some cases you will see a mic with a characteristic output impedance of , say 250 ohms and a recommendation that it be used with preamps that have a input impedance of say 600 ohms or higher. One thing people sometimes do is use a "Y" adapter to feed one mic into two channels of the XL1 (or other device). The XL1 has a input impedance of 600 ohms. They "Y" adapter efffectively parallels the input impedance, so the mic sees 300 ohms. This might present a problem for some mics - and it may appear as distortion at lower sound levels.