Author Topic: Line Audio Om1s fried (Read 9119 times)

MakersMarc · « **on:** July 11, 2015, 01:59:47 PM »

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 · « **Reply #1 on:** July 11, 2015, 02:36:24 PM »

Quote from: MakersMarc on July 11, 2015, 01:59:47 PM

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 · « **Reply #2 on:** July 11, 2015, 02:47:16 PM »

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

MakersMarc · « **Reply #3 on:** July 11, 2015, 02:58:35 PM »

Quote from: voltronic on July 11, 2015, 02:36:24 PM

Quote from: MakersMarc on July 11, 2015, 01:59:47 PM
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 · « **Reply #4 on:** July 11, 2015, 03:00:56 PM »

Quote from: voltronic on July 11, 2015, 02:47:16 PM

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 · « **Reply #5 on:** July 11, 2015, 03:02:42 PM »

Quote from: MakersMarc on July 11, 2015, 03:00:56 PM

Quote from: voltronic on July 11, 2015, 02:47:16 PM
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 · « **Reply #6 on:** July 11, 2015, 03:13:10 PM »

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 · « **Reply #7 on:** July 11, 2015, 09:50:58 PM »

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 · « **Reply #8 on:** July 12, 2015, 12:09:47 PM »

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 · « **Reply #9 on:** July 12, 2015, 01:23:07 PM »

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 · « **Reply #10 on:** July 12, 2015, 01:56:11 PM »

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 · « **Reply #11 on:** July 12, 2015, 02:22:41 PM »

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 · « **Reply #12 on:** July 12, 2015, 05:08:56 PM »

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 · « **Reply #13 on:** July 12, 2015, 08:18:10 PM »

FWIW, the 661 manual states:

Quote

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:

Quote

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

2manyrocks · « **Reply #14 on:** July 12, 2015, 09:30:20 PM »

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?

voltronic · « **Reply #15 on:** July 12, 2015, 10:05:02 PM »

Quote from: 2manyrocks on July 12, 2015, 09:30:20 PM

Just put those OM1s in the YS real cheap.

I'll take them if the price is right.

flipp · « **Reply #16 on:** July 12, 2015, 10:12:38 PM »

Quote from: ~Jon Stoppable on July 11, 2015, 02:35:00 PM

Both mics at the same time? That would be an incredibly rare failure. I'd suspect an incompatibility with the phantom supply first. Try the mics again with a different phantom supply.

Disable phantom on the 661 and insert something like a Denecke PS-2 in the chain to supply phantom. That way the only thing that has changed will be the source of phantom power. If subsequent recordings are fine then you know the problem is the 661's phantom supply; if recordings still have the same problem then the source of the problem lies elsewhere.

voltronic · « **Reply #17 on:** July 12, 2015, 10:15:57 PM »

Quote from: ~Jon Stoppable on July 12, 2015, 09:13:24 PM

Marantz means 10mA per channel, but that doesn't necessarily mean it's a quiet 10mA. The early Tascams could also do 10mA per channel, but were noisy even at no load.

OK, that makes more sense that it's per channel; I suppose 5mA per channel would really limit your mic choices. I still wonder if that spec could be fudged or rounded up a bit.

Not to pull this thing OT, but it would be really nice if manufacturers could be more thorough / honest on their spec sheets. It's hard to know if the numbers you're looking at are real or if they are massaged to hit the number people expect. I realize that's a marketing and sales issue though, so it would never change unless there were some kind of international testing standards everyone was held to.

2manyrocks · « **Reply #18 on:** July 12, 2015, 11:02:03 PM »

Quote from: MakersMarc on July 12, 2015, 05:08:56 PM

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.

The specs for schoeps cmc6 ug say 4mA at 48v and 8mA at 24v. The OM1 spec just says 4mV without making distinction for voltage. if the 661 can run Schoeps, looks like it should run OM1, But since the OM1 runs on the OP external preamp, the issue seems to be something other than the power supplied by the 661 to my superficial understanding? The OM1 appears to work, just not with the 661 as I understand what has already been posted.

Maybe the OP and Voltronic ought to get together on a deal.

MakersMarc · « **Reply #19 on:** July 12, 2015, 11:18:23 PM »

Yep, weird. Mk41 and 4022 no issues.

MakersMarc · « **Reply #20 on:** July 13, 2015, 11:51:02 AM »

Quote from: 2manyrocks on July 12, 2015, 11:02:03 PM

Quote from: MakersMarc on July 12, 2015, 05:08:56 PM
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.

The specs for schoeps cmc6 ug say 4mA at 48v and 8mA at 24v. The OM1 spec just says 4mV without making distinction for voltage. if the 661 can run Schoeps, looks like it should run OM1, But since the OM1 runs on the OP external preamp, the issue seems to be something other than the power supplied by the 661 to my superficial understanding? The OM1 appears to work, just not with the 661 as I understand what has already been posted.

Maybe the OP and Voltronic ought to get together on a deal.

The om1 ran beautifully into the Gak silvers>148>modsbm1>m1 no issues whatsoever, this is really weird. I'll be surprised if copper cables make the difference, I'll report when I get them, Doug is loaning me a pair, really nice of him.

MakersMarc · « **Reply #21 on:** July 17, 2015, 05:43:46 PM »

Quote from: 2manyrocks on July 12, 2015, 09:30:20 PM

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?

Good idea, had not tried.

MakersMarc · « **Reply #22 on:** July 19, 2015, 08:53:12 PM »

Star quads didn't make any difference. Dammit. And I tried running the mics into the 148 and then using the star quads into the 661. As with the Gak cables, no noise, clipping or any other problems. Appears to be an incompatibility between the om1 and the 661 p48. Only thing left to try is the 661 Walwart instead of 2400 eneloops.

MakersMarc · « **Reply #23 on:** July 20, 2015, 04:42:17 PM »

No change using the 661 DC power supply.

2manyrocks · « **Reply #24 on:** July 20, 2015, 10:56:35 PM »

Sorry about that.

MakersMarc · « **Reply #25 on:** July 21, 2015, 10:54:07 AM »

Good idea though, thanks.

MakersMarc · « **Reply #26 on:** July 31, 2015, 11:14:06 PM »

Big thanks everyone, particularly Jon, the resistor and mic loaners were greatly appreciated!

No improvement in the static and bricking though, Jon thinks it's likely the OM1 not being able to deal with the 661 p48 noise. Just one of those things, no ones fault. They do work with my 148 so rather than sell that as I'd thought of doing, prolly just keep the brick and the mics for a while. Weirdest damn thing, never ran across this before running mics directly into a phantom powering deck. :face-palm

MakersMarc · « **Reply #27 on:** August 01, 2015, 11:53:30 AM »

Could be a power issue, but I only run internals to hopefully avoid that stuff. Jon thinks it's just a quirk of the OM1 amd I wonder if the 661 is a little iffy with certain mics, apparently Rode and Beyer have similar issues. Shoulda bought a d8.