Topic: Line Audio Om1s fried

[MakersMarc]

So I thought the brick walling and static was my newer 661 but I ran the dpas into it and no problems. And tested the xlrs I used last night and they are fine with the dpas. But was able to recreate the bricking static into both 661s.

I listened to the recording, startled out with some music but static and skipping, degraded to just bricky static. Anyone have mics just die like that? I ran them once onstage with zero issues, line in to a 148 into my sbm1.

Any insights would be appreciated. Guess you get what you pay for.

[voltronic]

So I thought the brick walling and static was my newer 661 but I ran the dpas into it and no problems. And tested the xlrs I used last night and they are fine with the dpas. But was able to recreate the bricking static into both 661s.

I listened to the recording, startled out with some music but static and skipping, degraded to just bricky static. Anyone have mics just die like that? I ran them once onstage with zero issues, line in to a 148 into my sbm1.

Any insights would be appreciated. Guess you get what you pay for.

Possibly Captain Obvious questions:

Does it matter if you're recording loud or soft material?
Does the static happen in both channels?
Have you tested the mics individually?
Have you tried the OM1s into another preamp and/or a different recorder besides your two 661s?  There were some threads on GS about the 661 having an iffy phantom supply.  OM1's draw 4mA each; your DPAs are 2.6mA each.  That shouldn't make a difference, but it wouldn't hurt to rule it out.  The fact that you had no issues using them with another recording chain seems to be important.

It seems unlikely that you would have received two defective mics.  Could they have been damaged in between the time you used them with your 148/SBM-1 and then the 661s?  Saying "you get what you pay for" is premature, I think.  My CM3s have been rock solid in every situation this past year, and I have not heard one person ever complain about getting a defective mic from LA.  I'm not saying it couldn't happen, but let's make sure it's really the mics that are the problem.

If you do more testing and find the mics really are at fault, contact your dealer - I'm sure they will exchange them for you.

[voltronic]

https://www.gearslutz.com/board/remote-possibilities-acoustic-music-location-recording/508933-clipping-problems-marantz-pmd661-phantom-power-drop-spiky-sounds.html

[MakersMarc]

So I thought the brick walling and static was my newer 661 but I ran the dpas into it and no problems. And tested the xlrs I used last night and they are fine with the dpas. But was able to recreate the bricking static into both 661s.

I listened to the recording, startled out with some music but static and skipping, degraded to just bricky static. Anyone have mics just die like that? I ran them once onstage with zero issues, line in to a 148 into my sbm1.

Any insights would be appreciated. Guess you get what you pay for.

Possibly Captain Obvious questions:

Does it matter if you're recording loud or soft material? Both
Does the static happen in both channels? Yes
Have you tested the mics individually? Yes
Have you tried the OM1s into another preamp and/or a different recorder besides your two 661s?  Yes, I ran into my Oade 148 > line in to the 661 with no issues. Which makes me think it's the 661. There were some threads on GS about the 661 having an iffy phantom supply.  OM1's draw 4mA each; your DPAs are 2.6mA each.  That shouldn't make a difference, but it wouldn't hurt to rule it out.  The fact that you had no issues using them with another recording chain seems to be important.

It seems unlikely that you would have received two defective mics.  Could they have been damaged in between the time you used them with your 148/SBM-1 and then the 661s?  Saying "you get what you pay for" is premature, I think.  My CM3s have been rock solid in every situation this past year, and I have not heard one person ever complain about getting a defective mic from LA.  I'm not saying it couldn't happen, but let's make sure it's really the mics that are the problem.

If you do more testing and find the mics really are at fault, contact your dealer - I'm sure they will exchange them for you.

Answers above. Starting to think it's an issue with the 661 power supply, as the om1 sounds fine run into the Oade 148 preamp and line into the 661. Thanks!

[MakersMarc]

https://www.gearslutz.com/board/remote-possibilities-acoustic-music-location-recording/508933-clipping-problems-marantz-pmd661-phantom-power-drop-spiky-sounds.html

.

Wonder why I've had zero issues with 4022s?

[voltronic]

https://www.gearslutz.com/board/remote-possibilities-acoustic-music-location-recording/508933-clipping-problems-marantz-pmd661-phantom-power-drop-spiky-sounds.html

.

Wonder why I've had zero issues with 4022s?

They draw significantly less current, as I said in my earlier post.
EDIT: You wouldn't think the difference in current draw between 4mA and 2.6mA would make much difference, but it could if the supply isn't great to start with.  Jon will be able to better explain much better than I can.

[MakersMarc]

Thanks Voltronic. Disappointing, as I got the same result into my older also preamp modded 661. So I'd tend to think it's the p48 and not input clipping?

[MakersMarc]

Thanks Jon, most appreciated. Time for a bench test by Doug...maybe. If he thinks it's just an incompatibility issue is there even a fix? Really curious to see what this winds up being, hadn't heard about the 661 incompatibility issues until reading that gearslutz page and frankly had no idea p48 could have incompatibility issues with 48 powered mics.

[MakersMarc]

Doug mentioned that the only mic he's seen do this to a 661 was Beyer, and apparently Beyer chalked it up to "incompatibility". He said check cables and I'll also run both mics at the same time, thanks Jon.

Starting to get the idea that all in one p48 can be a little sketchy. 

[MakersMarc]

Interesting, just had never experienced these issues before.

So Jon, forgive my ignorance, but is there anything you build that would allow the Line audio mics to run into an inferior power source?

[MakersMarc]

Thanks Jon. Ay. Going to see what Doug and JP at Line Audio offer up if anything. I'm pretty convinced it's a power issue, both 661s behave the same when powering the Om1s.

[MakersMarc]

Doug suggested thst a switch from silver to copper star quads might help, he said it resolved they'd ever issues. Gonna try that.....

[MakersMarc]

And Jp says maybe a shielding grounding issue, so we'll see if the cable switch helps. And he says, sorry can't help. Don't really expect him to do anything just one of those things. Lucky dpas and Schoeps get along with the 661.

[voltronic]

FWIW, the 661 manual states:

Phantom power ......................................................... 48V, 10mA (Max.)

I take that to mean it can supply up to 10mA total to both channels.  A pair of OM1s are going to draw 8mA which may be exceeding what the 661 can actually supply.  The "Max" in their specs may be key, and the real number may be lower than what the OM1s are asking for.  Not sure if that qualifies as an incompatibility as is being discussed here.

Looking through some manuals for a few other popular recorders, most don't specify max current draw.  The manual for my 70D does have it, though I wonder if the spec is too good to be believed:

Phantom power: 48V +/-4V (10mA/CH)

[2manyrocks]

Just put those OM1s in the YS real cheap.

Dumb question but does the problem still happen if the 661 is run from a wall wart or whatever AC power source besides batteries?

More generally, is there a functional limit to which a battery powered recorder can  supply current beyond which one should not go?