Submitted by anonymous on Fri, 01/20/2006 - 06:44

A local pawn shop had a couple of these mics and after doing a little research on them decided to pick one up for the relative bargain price they're selling them at. The mic is an odd one...a broadcast mic with built in amplifier and limiter that puts out a line level signal. It is set up to use a battery (that's no longer available) or phantom power. Now, seeing it puts out line level, one would not use a preamp for it. I initially assumed I could use the outboard phantom power unit I have and just plug it straight into a compressor and use the gain control to control the level going into the DAW. This really does not work well. Now I'm thinking that I treat this like an instrument and run it into a D.I. input? Anyone out there that can help me with this. The thing's not working well for me and I'm wondering if I should go back and swap it out for the other SM82 they have to determine if this one has problems.

Here's some info on the mic; http://www.coutant.org/sm82/

Thanks in advance for any input!

Comments

You need to provide us with some specifics. Like what are you terminating it into? An XLR line input is what this puppy was designed to see- and that may be the problem right there. If you are plugging it into an XLR MIC input on a board (so that you are providing the phantom power), that might be an issue because the MIC in will provide the wrong load and level. Result will be DISTORTION. If you use a simple external phantom power box (like a Stewart or A-T), then run the mic into a balanced line input, that MIGHT work better. You will most likely require rigging up an XLR-to-TRS1/4" adapter cable, as most balanced line ins are TRS 1/4" instead of XLR (but not all).
The DI approach...well, DI's do not provide phantom power, they (in some cases) require it to operate. And they are designed to load an UNBALANCED input source, like a geetar or bass or keys. Terminating this mic into an UNBALANCED input will not work properly, and you might even damage the output circuit.
You will have to "pad" the signal coming out of the mic with an "inline attenuator" of the sort like Shure or A-T sell. And then, that will have to be inline AFTER the external power supply in the chain leading to the mixer input(these attenuators do NOT pass phantom on to the mic!) This is a pain and about $150-200 to set up just to see if the mic operates correctly, and these might be crapped-out already if somebody has abused them! Too bad it uses a mercury battery... :evil:

This will not need phantom power at all. And I say that if you intend on using it with the battery installed. What I read is it will work this way but will be line level...with out the battery may be when it needs to see phantom power. Treat it like a Balanced line level device.

Its the Chris Schenkle mic! Ya know....Wide World of Sports from the Alps etc etc.

That's what I thought that I said. It is a balanced line source.But it needs phantom power to operate it, as mercury batteries (like the TR177 Duracell) are no longer made. Do balanced line ins provide phantom? No, so you need to provide that from an external box. Or get a board like a Yammie PM2000 (probably what this mic was used with at those olympics!) that has balanced mic ins with phantom AND enough stepped input attenuation to "pad" down the level as to not overload the pre.
BTW, how much was the mic?

Hey guys...thanks for the input. I just got hip to the fact that the thread has generated some responses.

I actually already have inline attenuators and a Rolls phantom power box. It seems you could stick the attenuator on the output of the phantom power to use it that way. (?)

I actually set the mic aside since it was kind of baffling me, but will probably pull it out this weekend. I am going to try and run it into instrument D.I. inputs on one of my preamps to see how that works using balanced XLRto TRS cables that I have. I had originally thought that I should just be able to plug it right into a compressor and use the gain control to adjust the input going into the A/D converter, but had no luck with that.

I got it fairly cheaply and it looks to be in pretty good shape. I purchased a well worn but functional EV 635a and the SM82 for $50. Pretty decent deal...just hope the mic works since I doubt they'd take it back at this point with my procrastination on putting the mic to test.

Yes, if you use the Rolls phantom power box, you will need to place the inline attenuators at the output of the box. Attenuators like that won't pass phantom power onto the mic.
$50.00 was probably a decent deal, especially if the 635 works OK. The 635 can be handy in many musical ways. And if you can get the 82 to work (BTW, if you are still having problems, it might be that the little switch in the XLR connector is on the fritz and not powering up the mic), so much the better. It might make a great "experimental" special effects
mic. Try using it as a room mic. Or, put a small speaker in , say a bathroom, run a track to the speaker, and mic up the sound with the 82...you never know, baby!

Well...I gave it a try using the Rolls phantom power box, then sending the signal into the DI input of a Sebatron preamp with an XLR to TRS mic cable. I think the mic is not functioning. There is some signal passing through, though the gain needs to be cranked pretty high on the pre, but it's dominated by a nasty crackling, static 'rush' that fades in and out. I've hung onto the mic long enought that I'm not sure the pawn shop would take it back. They did have two more SM82's there so I'm thinking of trying to swap it out for one of them. If not...I guess I just bought an expensive 635a mic.