Topic: Noisy DPA 4061 (or DAD6001 adapter)

[glennjr]

I'm wondering if anyone has ever had any experience with a noisy 4061? I gambled on an ebay 4061. It appears to be legit (don't know if they even make fake ones), but the wire was quite sticky and had some interesting smell. Everything else looks good thought. Despite this, I bought a new DAD6001 adapter locally.

From what I've read, this mic is supposed to be reasonably quiet, right? This isn't at all the case here. I can say it's by far the noisiest mic I've got. However, I have no experience with lavs.

I'd like to narrow it down to the mic or the adapter, but have no other way to use the mic without the adapter....

At this point, I just want to make sure if there actually IS a problem...or if this is just how lavs sound. (My other mics sound fine in the same recording chain.)

Thanks for your thoughts.

[it-goes-to-eleven]

They are very quiet.

What type of noise is it?

[glennjr]

Sounds to me like self noise.

[Gutbucket]

Mic is probably bad.
If you are in the USA, DPA in CO will check it for a fee, something like $25 last time I sent in one a couple years back.  Not much they can do if it's bad other than let you know, maybe reterminate the cable for you, but that's not likely to be the problem.

[Gutbucket]

Good advice from Jon as always.
 
You can try cleaning it by removing the grid and immersing the mic in distilled water and swirling it around. Really, distilled water won't hurt it. That's the reccomended DPA cleaning proceedure. It won't work again correctly until it dries fully.  Also hold the removed grid up to the light to check that its not clogged.  You can use dish-soap and a toothbrush on that if it's off the mic.

I've had a few 4060s go bad over the years and once bought a cheap bundle of used 4061s off ebay of which only a few were good. I've found that in general as they go bad they first tend to drop 5 to 10dB in sensitivity (in which case compensating with additional gain raises the self-noise floor by the same amount), then get noiser and/or have frequency response issues, or get noisy in more of a 'spitty' way.

[glennjr]

I compared it directly to a Gefell M930.  My experience with my other mics didn't produce that much noise , but I'll give them a listen again. And will try your recommendation Jon.

[EDIT: Just realized how low noise the M930 is, so not exactly the best comparison. I use a 416 often and it doesn't seem as noisy.]

I originally bought this to record engine noise from a scooter tailpipe. So I doubt  any noise I'm hearing from it now will be an issue for that. But I was hoping to use it for other duties.

And the grill is clean; will try cleaning it with distilled water later and see what happens.

BTW, any issues ever with the DAD6001? I really doubt this is the problem, but first have to rule it out.

Thanks everyone for the help.

[Gutbucket]

[edit, Jon beat me to the post.. posting anyway]

I've never used an M930 but I do know it has a very, very low noise floor compared to even other large diaphram mics, all miniature mics with tiny .25" or smaller diaphrams will be significantly noiser than that mic, including without question a properly working 4061.  The 4060 is both quieter and significantly more sensitive than the 4061, making it 'quiet enough' for most of my uses.  The 'good' used 4061s which I selected out of that ebay bundle are quiet enough for loud amplified material, but not quiet enough for acoustic stuff for me.

I have one DAD6001.  I haven't checked to confirm, but I suspect it may invert polarity.  I also use Jon's (Niant) PFA adapters with the miniature DPAs which provide the same functionality but without the microdot input.  Besides the possible polarity inversion, there is a slight signal difference of a few dB between them- using the same mic, the PFAs output a slightly hotter signal than the DAD.

[Gutbucket]

That is of course the other possibily.  Thanks for letting me know its likely the two-wire PFAs doing the inverting.  I haven't checked polarity of those either, just surmised it had to be one or the other phantom adapter when I found I needed to invert polarity of the single mic using the DAD6001 to match that of four others using your PFAs.  I asked DPA before using any of these adapters and was told the 406x output is positive polarity.  When you built the PFAs for me I did mention I would be using them with 4060s but didn't know to request that they be non-inverting at the time.  Not a huge deal to invert later of course.  Good to determine the source of it so that I can make accomodations as necessary.

[glennjr]

Thanks everyone for your advice. I will try everything mentioned and report back (for those interested).

And yes, I hadn't really thought about my threshold for what's considered "noisy". Recording voice over for the past several years has probably made me a bit too sensitive. I've done everything I can to eliminate noise (to my spouses dismay at times!) and in most cases have chosen microphones known for being quiet. Hopefully that's just the case here.

Also, this is technically the first omni that I've owned. (unless you consider some crappy computer bundled mic 10 years ago) Would an omni give the impression of sounding noisier than say a cardiod/hyer/super do to the pickup pattern? Basically collecting the noise floor from "all directions" instead of just one direction? In a sense, giving the illusion of being noisier?

That's probably not how it works, but just semi-educated thought.

Thanks!

[RichT]

Quite a few of these get sold on ebay after theatre runs, they're usually covered in makeup- it's a bit of a gamble of how long/if they work, hence the prices being much lower than new

[glennjr]

I would say that's spot on in this case. The return address looked odd to me. Did an Internet search and it belongs to a Disney cruise line. I hadn't thought it was actually used on ship - just figured an employee was selling them. Not that it matters if it works. But interesting to know.

[adrianf74]

I know it's all been said above but I'll add in my $0.02.   

I've owned the 4061 and found it "noisy" when recording really quiet passages in concert hall/small 1000 seat venues.  You can hear the hiss clearly during these points (epsecially after normalizing a recording).    I usually aim to set my recording levels around -6 to -10dB for peaks (some suggest -12dB) but I had a recording last yeart that was peaking around -30dB during the opening number.  As soon as I boosted the levels for that track the hiss was extremely noticeable. 

Likewise, if the mics came from Broadway / Vegas / Cruise Line / etc., they've probably been banged around a lot.   I owned a pair of said mics for about a year before I moved to the Countryman B3's (which have a self-noise level of -24dB which is marginally better than the 4061's).   The reason I did this is because I preferred the sound of the B3's (more neutral) and they were slightly quieter.  Most importantly, the mics were new and not tossed around.   For what we're doing, I'd rather *NOT* take a chance on beater mics especially if they crap out during that "one in a million" performance.

[Cheesecadet]

Good advice from Jon as always.
 
You can try cleaning it by removing the grid and immersing the mic in distilled water and swirling it around. Really, distilled water won't hurt it. That's the reccomended DPA cleaning proceedure. It won't work again correctly until it dries fully.  Also hold the removed grid up to the light to check that its not clogged.  You can use dish-soap and a toothbrush on that if it's off the mic.

I've had a few 4060s go bad over the years and once bought a cheap bundle of used 4061s off ebay of which only a few were good. I've found that in general as they go bad they first tend to drop 5 to 10dB in sensitivity (in which case compensating with additional gain raises the self-noise floor by the same amount), then get noiser and/or have frequency response issues, or get noisy in more of a 'spitty' way.

So I stopped by DPA today in CO to give my mics a check up and asked Michael if people actually cleaned their 4061s with distilled water like it mentions on the DPA Mic University FAQ.  He said that if it were him he would not.  Although the moisture would dry out over time they would have to be VERY delicately swirled in the water to not risk damaging the element.  He said if they were hs mics that he would never do that.  He did also mention to rub olive oil occasionally on the wires (making sire to avoid capsules and connectors) to keep them flexible for a longer period of time and avoid cracking.  Make up your own mind on how you clean your mics, but this came from the mouth of the guy who repairs them for a living.

[it-goes-to-eleven]

Interesting.  Olive oil goes rancid within one to two years after processing into oil, and faster if exposed to light and O2. Mineral oil is usually a better choice for many applications because of that.  Silicone grease is frequently used on rubber to prevent cracking.

[Cheesecadet]

That is interesting.  He did say wipe it on let sit for a minute and wipe off.

I found his insight on the whole distille water trick more interesting