Topic: DPA 4060 ebay ex-theatre mics very noisy - are they fried?

[it-goes-to-eleven]

Luckily for folks like us, they often get sold off cheap just to make some money back and are still usable.

That's it exactly, I think.   Sell them before they fail, so you get some money out of them.  They probably buy lots at a time.  Maybe they get a discount, especially if they are a non-profit theatre?

I got lucky - my ebay theatre dpa's have been great.   But new or used, those little mics scare me a bit because they can't be repaired if the capsule/cable interface is damaged.   I don't know how much life they have left, or how much of a tug would damage them.  So I always treat them as gently as possible.

I am also hesitant to loan them out, because it'd be a pain if something happened.  How would you handle it?  Finding a replacement pair on ebay would be a major chore.  And the pair you got might not be good.  Etc.

[Gutbucket]

FWIW, I used numerous DPA 4060s over the past 6 years, purchased both new and used, and I've never had a cable failure at the mic or anywhere other than an accidentally yanked off microdot. I've had FETs go bad (not repairable) and solder joints in re-terminated connectors go bad (pretty easily repairable).   On one very early production pair which I bought used (low serial numbers, different cable type), the cable covering hardened, cracked and begain to fall off in large chucks.  The stranded ground/shield copper underneath was heavily patina'd green but the mic worked fine. I recovered it with heatshrink and used it for another 6 months before it died of FET failure. 

My FET failures manifested as a permanently reduced sensitivity of 6+dB, increased noise, and sometimes sensitivity changes while recording (higher SPLs 'woke them up', lower SPL's were more problematic).

[dogmusic]

FWIW, I used numerous DPA 4060s over the past 6 years, purchased both new and used, and I've never had a cable failure at the mic or anywhere other than an accidentally yanked off microdot. I've had FETs go bad (not repairable) and solder joints in re-terminated connectors go bad (pretty easily repairable).   On one very early production pair which I bought used (low serial numbers, different cable type), the cable covering hardened, cracked and begain to fall off in large chucks.  The stranded ground/shield copper underneath was heavily patina'd green but the mic worked fine. I recovered it with heatshrink and used it for another 6 months before it died of FET failure. 

My FET failures manifested as a permanently reduced sensitivity of 6+dB, increased noise, and sometimes sensitivity changes while recording (higher SPLs 'woke them up', lower SPL's were more problematic).

Did you happen to download my second recording sample? I would like to know your opinion if this sounds like an FET failure. (Be sure to keep your playback volume low.)

http://www.box.net/shared/is8omc9390j1ng2sxq5e


Also, have you ever taken off the grids to clean them? I wondered about giving this a shot, but can't seem to budge the grid on this mic.

I think I read one of your posts where you had a set of DPA's that worked with PIP and another that needed more voltage. Did you ever figure out why one did and one didn't?

Thanks,

Phillip

[Gutbucket]

Haven't listened to the sample and unfortuantately I'll not have a chance to for a while (just got home late last night from a fest and I'm working an industry show that starts tomorrow and runs for a week).

The grids just interference fit and pull off.  I used to take them off regularly when I was concerned about the capsule orientation for boundary mounting.  Now I remove them less frequently since internal orientation didn't seem to matter that much.  There is a plastic ring that the metal mesh attaches to as a permanent part of the grid. The plastic ring is what makes an interference fit on the mic body.  Carefully pull that.  Problem is that there isn't much body left on the cable side to hold while you do, and most that is tapered.  If that ring is really stuck, clean off the crud with some isopropyl alcohol (don't let the disolved crud get in the mic through the screen) and swizzle the whole thing in distilled water.  If you get the grid off you can re-swizzle the bare capsule in distilled water as well, but most crud will probably be stuck in the mesh so throuroughly clean the grid when it is off the mic and you needn't worry about messing up the capsule.

I always recommend using a battery box, external preamp, or phantom adapter that provides 5V-10V mic powering.  Even if the mic operates on built-in PIP of less than 5V, it will probably not do so optimally or to specification.  The pair that seemed to work was the very old used pair with low serial numbers and the cable sheath cracking problem.  The only other pair I had at the time was a new pair which did not work with PIP.  I didn't record any music or try any of my other 4060s this way.

If you absolutly need to have a DPA miniature omni that works on typical ~3V PIP, look into the 4063.  It has similar sensitivity to the 4061 is built to operate on lower voltage powering.  The specs suffer a bit for that ability, and I'd think not many outfits use those so don't expect to find those used or get a great deal on them.

[dogmusic]

Haven't listened to the sample and unfortuantately I'll not have a chance to for a while (just got home late last night from a fest and I'm working an industry show that starts tomorrow and runs for a week).

The grids just interference fit and pull off.  I used to take them off regularly when I was concerned about the capsule orientation for boundary mounting.  Now I remove them less frequently since internal orientation didn't seem to matter that much.  There is a plastic ring that the metal mesh attaches to as a permanent part of the grid. The plastic ring is what makes an interference fit on the mic body.  Carefully pull that.  Problem is that there isn't much body left on the cable side to hold while you do, and most that is tapered.  If that ring is really stuck, clean off the crud with some isopropyl alcohol (don't let the disolved crud get in the mic through the screen) and swizzle the whole thing in distilled water.  If you get the grid off you can re-swizzle the bare capsule in distilled water as well, but most crud will probably be stuck in the mesh so throuroughly clean the grid when it is off the mic and you needn't worry about messing up the capsule.

I always recommend using a battery box, external preamp, or phantom adapter that provides 5V-10V mic powering.  Even if the mic operates on built-in PIP of less than 5V, it will probably not do so optimally or to specification.  The pair that seemed to work was the very old used pair with low serial numbers and the cable sheath cracking problem.  The only other pair I had at the time was a new pair which did not work with PIP.  I didn't record any music or try any of my other 4060s this way.

If you absolutly need to have a DPA miniature omni that works on typical ~3V PIP, look into the 4063.  It has similar sensitivity to the 4061 is built to operate on lower voltage powering.  The specs suffer a bit for that ability, and I'd think not many outfits use those so don't expect to find those used or get a great deal on them.

Thanks for all that info. Regarding cleaning the mic, DPA's user manual seems to be against cleaning the element with anything but a dry cotton swab. Is it really okay to dip the entire mic in distilled water?

I don't really need the mics to run on PIP. There are some postings on the web where people have managed to do this, and I had expected mine would as well. It's no big deal to use a battery box now that I know.

[Church-Audio]

One of my best friends is one of the top Live sound engineers for the Toronto Theater community he has been doing sound in theaters for over 40 years and has worked on Broadway ect.. This is what he said when I asked him about theaters selling off good mics.

So you know I am not talking out my ass.

"Bob Shindle

Well, it really depends on the show, and the producer. In the older days when there were actual stars in the shows we would change them out at regular intervals instead of waiting for a burnout. Nowadays you're right though. I don't know of any producers who will incur the expense for no reason. And most shows don't have big names any more. So, yes I would say I agree with you. Once they have sweated out you can still get a bit out of them, but the salt from the sweat has already started to rot the metal"

As far as community theaters are concerned yeah they dump the mics sometimes but very rarely because if they sell a mic they have to put that money back into the theater budget that means next year they get less grant money. Again nobody is going to get rid of a perfectly good mic. Why would they? Why sell a mic for 1/4 its value? If the mic we perfectly working it would be worth at least 50% of its value as mics don't depreciate that much. 

[yousef]

Thanks for all that info. Regarding cleaning the mic, DPA's user manual seems to be against cleaning the element with anything but a dry cotton swab. Is it really okay to dip the entire mic in distilled water?

I think I learned about the distilled water method from a Brian Skalinder post here quoting someone from DPA - I'm sure that searching DPA plus distilled water on these boards will eventually turn it up.

Interesting about what a FET failure might present as - I wonder if that's what's happened to one of mine...

[dogmusic]

Well, strange things do happen. I went out to hang up the kayaks under the screen porch for winter. The bottom of the porch is about 10 feet off the rock that our house is built on, and while balancing on the edge of a picnic table and raising up the end of the kayak with one hand, I pulled up with the other hand on a bungee cord to attach it to a hook under the porch, when suddenly the bungee slipped out of my grasp and the metal part boomeranged back and slammed into my forehead. I almost blacked out.

So while recovering my consciousness, I decided to give those mics another go. Gutbucket had posted regarding DPA FET failures that "higher SPLs 'woke them up' ". So I gave a couple of really loud hand claps in front of that noisy mic. I made a recording and the noise seemed to be lessened. Then I plugged the battery box line-in rather than mic-in as I had been doing, did a test recording with my out-of-tune piano and --- a miracle! The noise seems to be completely gone!

Here is a sample: The 4060's are just sitting on top of the closed lid of my piano, and the chain is DPA 4060's > RCA adapter > SP-SPSB-8 batt box > D50 line-in, rec level 3.0.

http://www.box.net/shared/n8qf3jtz0rmv1dq47xxj

I'm not sure if this is a fluke and that the mic will bounce back into noise (like a bungee cord to the head), but I'll run some longer recordings later and see if it stays quiet.

Thanks once more for everyone's help. And thanks, Gutbucket, for that little nugget of info.

Phillip

[adrianf74]

@Church-Audio: I've never, nor has anyone here, said you were talking out of your ass.  All theatres are different.  I'm doubting your contact and his experience but I've spoken to a musical director at a long-running broadway show and he's told me that they do cycle through their mics to try and avoid major issues.  A lot of the "luck" of the draw isn't really luck but knowing that the seller has tested them prior to putting them up for auction/sale.  Many of us (myself included) have ex-theatre mics and have ZERO issues (other than the expected dB difference between them which is still not really an issue).  In my case, I know who cleaned them up and terminated them and that the person I bought them from treats his stuff very well.   In the case of dogmusic, he might have gotten a "dog" mic (it does happen).

@Gutbucket: Thanks for the info on the FET failure and what that looks like.  I know I don't suffer from this (yet) - touch wood - but will keep my ears (and eyes) open just in case.

it-goes-to-eleven: I doubt there's any "bulk purchase" discount available on them when the best price I'm seeing is around US$450-470.  As far as the "mileage left" goes, I would just say to treat your current mics as well as you treat any other gear.  I try not to pull on the cables or be rough with the capsules -- I always throw them in an earplug case (the capules) when I'm done recording and then place them back in the DPA box when I get home and they're not in use.   The good news is that if you ever had a dud pair, the "replacement" cost from DPA is ~$300 per mic for brand new ones.   Figuring that you paid around ~$100 per mic, you still paid less for them if you ever had to replace them outright (or you could roll the dice and try FleaBay again but that can be hit or miss as has been shown).

dogmusic: With the 406x mics, I'd always want to use a battery box at a minimum or a preamp if you had access to one.   Makes controlling them a lot easier.  I'm glad that it looks like you got them to wake up.   That's an old trick that also helps (the hand clapping thing).  Let us know if the noise comes back.

[dogmusic]

In the case of dogmusic, he might have gotten a "dog" mic (it does happen).

That's an old trick that also helps (the hand clapping thing).

Well, I guess you can teach an old "dog" old tricks. 

[John Willett]

Personally I would never buy ex-theatre tie mics. as they are very likely to be sweated-out.

This tends to be the main problem with mics. used in the theatre.  Also the possibility of damage due to make-up and/or hair-spray.

[Church-Audio]

Well, strange things do happen. I went out to hang up the kayaks under the screen porch for winter. The bottom of the porch is about 10 feet off the rock that our house is built on, and while balancing on the edge of a picnic table and raising up the end of the kayak with one hand, I pulled up with the other hand on a bungee cord to attach it to a hook under the porch, when suddenly the bungee slipped out of my grasp and the metal part boomeranged back and slammed into my forehead. I almost blacked out.

So while recovering my consciousness, I decided to give those mics another go. Gutbucket had posted regarding DPA FET failures that "higher SPLs 'woke them up' ". So I gave a couple of really loud hand claps in front of that noisy mic. I made a recording and the noise seemed to be lessened. Then I plugged the battery box line-in rather than mic-in as I had been doing, did a test recording with my out-of-tune piano and --- a miracle! The noise seems to be completely gone!

Here is a sample: The 4060's are just sitting on top of the closed lid of my piano, and the chain is DPA 4060's > RCA adapter > SP-SPSB-8 batt box > D50 line-in, rec level 3.0.

http://www.box.net/shared/n8qf3jtz0rmv1dq47xxj

I'm not sure if this is a fluke and that the mic will bounce back into noise (like a bungee cord to the head), but I'll run some longer recordings later and see if it stays quiet.

Thanks once more for everyone's help. And thanks, Gutbucket, for that little nugget of info.

Phillip

I have done the same dam thing but not with a Kayak. It hurts me to just think about it. Hope your head feels better. My theory behind the failure of the fets is that sweat corrodes the metal leads of the fet and works its way inside the fet and partially shorts it out. Thus any mic that has been sweated out is on borrowed time. Like others have mentioned a tell tail sign of a mic that has been exposed to sweat will be the sham rock green shield wire when you strip it to put the connector on.

[Gutbucket]

John posted whil I was typing with a similar sentiment on sweat and hair spray.. here's the post-

Check your cables and solder connections.  That's the usual culprit and soldering those hair thin signal conductors is not super easy.  A compromized joint can also 'awaken' if enough juice flows to bridge the resistance of a 'sometimes but not always' intermitant connection or a cold solder joint.  I'd suspect that before a bad FET.  DPA can check and confim a bad FET, but will need to cut off any custom termination in their troubleshooting to do so.

Chris Church knows his stuff.  He knows mics from both the technical and the practical 'real world' side.  I think he's right on with his comments.  It's contaminants in sweat (especially the salt) and arisol sprays that concern me the most and which I believe are most likely to kill theater, film or TV sourced mics at some point.  The makup, paint, tape goo and outside uglyness don't make it past the metal mesh grid for the most part, which is easily removed, cleaned or replaced.  It's the mostly unseen moisture-born contaminants that are the problem. That's what's up with the recommendation for nothing but distilled water to clean the naked capsule- distillation removes all minerals and other residual contaminants.  I've had several people at DPA in the US confirm that the distilled water swizzle is OK, but I've never felt the need to do that myself yet. I had one of a pair stop working when soaked with rain at a fest, but continued working and was fine once it dried out later that day.  Probably would have been wise to swizzle those afterwards but they are still working correctly 4 years later, then again it was soaked by clean rain water directly from the sky.  If it was sweat saturated I would have dunked it for sure.

I have bought a batch of B3s and more recently 4061s off ebay.  The seller was reputable, & claims to test for operation beforehand.  They came clean. The six B3s all worked fine.  I haven't had time to check the batch of 4061s yet, but bought from the same vendor as the B3s and I feel confident they'll be OK.  Don't know where he gets them.  I was prepared for problems or limited longevity. Caveat emptor.

[it-goes-to-eleven]

Wait a minute.  Are you saying that the bungie hit your head, and knocked some sense into you?  And then you took it out on the microphone, and after screaming into it (*), it started working better?

That's amazing!

Or maybe the knock on the head is causing audio hallucinations?

EIther way, it works!  It only matters how it sounds to you

You are very lucky the damn bungie didn't rip your eye out!

* - I know you said claps but screams make a better story.

[Gutbucket]

You are very lucky the damn bungie didn't rip your eye out!

I've done it. The thought of that hook potentially catching an eye freaked me out way more than the big knot on my forehead.  Yikes.