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Author Topic: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?  (Read 5980 times)

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Offline fandelive

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Hello,

I recently purchased 2x said to be DPA4061 from an ebay reseller. I chopped the two original LEMO plugs and made them terminated with one single mini-jack plug.
I taped a show yesterday and distortion occured on bass drum. I think that should not happen with DPA4061...

Setup :
2x DPA4061 > CA-9100 preamp (gain between 11 and 12 o'clock) NO bass roll-off or HPF > Tascam DR-2d (line-in @ 96/100)

When you check the waveform, it approximately reaches the -5dB peak.
When you listen to the recording, it's distorted on bass drum. Brickwalling occured.
Here's a sample : http://cmlien.free.fr/ts/DPA.mp3

I've got a backup source made with MM-HLSC-1's (4.7k modded) and the sound is clean (waveform also approximately reaches the -5dB peak).

It's a shame if DPA4060 were sold for DPA4061. Is there a way to visually tell the difference between DPA 4060 and 4061 ?
I know they came from London musicals. Mics still had some painting marks and actors names on the wires when I got them.


I taped another show about one month ago and brickwalling didn't occur at all. I didn't felt like the sound was THAT lower at the venue (still a hard rock concert) but I could have been mistaken because I always wear earplugs.
Setup was : 2x DPA4061 > CA-9100 preamp (gain @ 11 o'clock) NO bass roll-off or HPF > Tascam DR-2d (line-in @ 96/100)

This time waveform barely reached the -20dB peak, but when normalised to 0db, I could hear no distortion.
Here's a sample : http://cmlien.free.fr/ts/sample_DPA4061.mp3


Any ideas on where this distorted sound comes from ?

9V battery into the CA preamp was used for approximately 9 hours.
I had fresh batteries into the Tascam.

Thanks,
-fandelive
« Last Edit: May 08, 2016, 02:06:20 AM by fandelive »
Mics : Sony ECM-717, SP-BMC-12, MM-HLSC-1 (4.7k mod), 2x DPA4060, 2x DPA4061
Battery box : SP-SPSB-6524 w/bass roll-off filter, MM-CBM-1
Preamp : Church Audio CA-9100
Recorders : Sony MZR-700PC, Edirol R-09HR, Tascam DR-2d

Offline beatkilla

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Re: Brickwalling with DPA4061 ?
« Reply #1 on: May 07, 2016, 07:34:40 AM »
When i ran 4061s i found there output too be very hot i used an attenuator.Maybe using extra gain was your mistake.

Offline ilduclo

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Re: Brickwalling with DPA4061 ?
« Reply #2 on: May 07, 2016, 09:56:23 AM »
As a long time 4061 user, I'd really doubt that the mics could be the source of the distortion,  I've run mine in music so loud that earplugs and fingers jammed in my ears are not enough, painful volume. I never have run a preamp, battery box only. I'd suggest that set up for all loud shows, for sure. It should eliminate your issues. There is no reason I can think of to have a preamp in the set up for anything with much volume at all, as I said, I've never run one, even for quiet acoustic music. My set up is ALWAYS dpa4061's together on single 1/8" plug, SPSB3 battery box (I only change batteries 1x yearly) mic in to Sony d50. Works for me, no distortion EVER ;D

Offline fandelive

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Re: Brickwalling with DPA4061 ?
« Reply #3 on: May 07, 2016, 11:40:54 AM »
When i ran 4061s i found there output too be very hot i used an attenuator.Maybe using extra gain was your mistake.

Can extra gain from a preamp cause brickwalling or distortion when the waveform of the recording doesn't reach the 0dB threshold ?
Because my recording is not clipping.


As a long time 4061 user, I'd really doubt that the mics could be the source of the distortion. [...] My set up is ALWAYS dpa4061's together on single 1/8" plug, SPSB3 battery box (I only change batteries 1x yearly) mic in to Sony d50. Works for me, no distortion EVER ;D

I have a cheap battery health tester. It lights a scale of red leds depending on how healthy the battery is.

I just tested the 9V battery I used for about 9 hours only with the DPAs and the CA-9100 preamp (line-in) and the tester said the battery is "weak".
I also tested the 9V battery box I used for about 9 hours only with the MM-HLSCs and the SP battery-box (mic-in, juice from the bbox only, no PIP) and the tester said "normal".

Could the DPAs be such a power hogs that I'd need to replace the 9V battery after 6 hours only of use ???
And can a weak battery cause brickwalling ? (not enough juice to power the mics)
« Last Edit: May 07, 2016, 11:42:59 AM by fandelive »
Mics : Sony ECM-717, SP-BMC-12, MM-HLSC-1 (4.7k mod), 2x DPA4060, 2x DPA4061
Battery box : SP-SPSB-6524 w/bass roll-off filter, MM-CBM-1
Preamp : Church Audio CA-9100
Recorders : Sony MZR-700PC, Edirol R-09HR, Tascam DR-2d

Offline ilduclo

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Re: Brickwalling with DPA4061 ?
« Reply #4 on: May 07, 2016, 01:11:13 PM »
yes, a weak battery can cause overload, one of my first mistakes ever taping, and also, yes, your battery could be dead early if you leave your mics plugged in, it seems to continue to draw power, despite not recording anything. So, for my one year plus 9v battery life for dpa 4061's, I plug the mics into the battery box only just a couple minutes before recording and I unplug them at the end of the night (not usually between bands or sets, though). If your std battery box works with the dpa's, I'd use it almost exclusively over the preamp, just my opinion, of course, but recording bands like Melvins, Mike Watt and Dinosaur Jr, I haven't had a brickwalling issue, even when recording right near the drums or the stacks

sooooooooo, use the sp battery box with a decent 9v and your dpa's, should be good for all loud shows, for certain!
« Last Edit: May 07, 2016, 01:13:54 PM by ilduclo »

Offline fandelive

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Re: Brickwalling with DPA4061 ?
« Reply #5 on: May 08, 2016, 07:31:25 AM »
sooooooooo, use the sp battery box with a decent 9v and your dpa's, should be good for all loud shows, for certain!

Thanks about the advice on not letting the mics plugged in. I can't remember whether I did it or not in the past...

Since the 11 o'clock position on the CA-9100 is 0dB, I guess it's just like using a 9V battery box.
Mics were powered by the preamp. No gain added.

I hope my issues were because of the weak battery.

Mics : Sony ECM-717, SP-BMC-12, MM-HLSC-1 (4.7k mod), 2x DPA4060, 2x DPA4061
Battery box : SP-SPSB-6524 w/bass roll-off filter, MM-CBM-1
Preamp : Church Audio CA-9100
Recorders : Sony MZR-700PC, Edirol R-09HR, Tascam DR-2d

Offline MJ

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Re: Brickwalling with DPA4061 ?
« Reply #6 on: May 16, 2016, 04:22:41 AM »
sooooooooo, use the sp battery box with a decent 9v and your dpa's, should be good for all loud shows, for certain!

Thanks about the advice on not letting the mics plugged in. I can't remember whether I did it or not in the past...

Since the 11 o'clock position on the CA-9100 is 0dB, I guess it's just like using a 9V battery box.
Mics were powered by the preamp. No gain added.

I hope my issues were because of the weak battery.

I believe that DPA does not need much of battery.  Many people use it with the plug-in on the tiny recorder like Sony M-10.  I guess that the 11 o'clock position on the CA-9100 must be way too high for the loud rock shows....  I got the brickwalling with DPA4061s>Chruch Pre (10 o'clock position) at White Snake. Now I set 9 or 8 to be on the safe side. 
<Main Rigs>
Schoeps MK4s>(Nbox Active cables)>Nbox+ or Nbox Platinum>Izzy (Split) Cables>Sony PCM-M10 or Sony PCM-D100

<Sub Rigs>
(1)DPA4061s>(terminated with 3.5 stereo mini)>Church Audio Pre>(3.5 stereo mini+Canare cable + 3.5 stereo mini)>Sony PCM-M10
(2)DSM-6S/L>(terminated with 3.5 stereo mini)> Sony PCM-M10

Offline Gutbucket

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #7 on: May 16, 2016, 09:27:42 AM »
When you check the waveform, it approximately reaches the -5dB peak.
When you listen to the recording, it's distorted on bass drum. Brickwalling occured.
I've got a backup source made with MM-HLSC-1's (4.7k modded) and the sound is clean (waveform also approximately reaches the -5dB peak).

In that case it's most likely preamp distortion, and my first suspicion would be a battery with insufficient voltage as surmised above.  The clean backup recording rules out the source being distorted prior to you recording it, which may not be as audible at the live event as it is later when listening back to the recording.

Quote
It's a shame if DPA4060 were sold for DPA4061. Is there a way to visually tell the difference between DPA 4060 and 4061 ?
I know they came from London musicals. Mics still had some painting marks and actors names on the wires when I got them.

If the band around the cable which has the serial number printed on it is red, its a 4061.
If the band around the cable which has the serial number printed on it is white, its a 4060.

To be safe I change the 9V batteries after approximately 12hrs in my two original CA-UGLYs (same circuit as the 9100 I believe) which I use with 4060's.  Low battery voltage causes distortion exactly like you describe. It is first noticeable in the low bass.

Check battery voltage after the recording session, with the battery still in the preamp circuit and the preamp turned on.  Once the preamp has been off for a while, a spent battery will recover somewhat and may show a false higher Voltage reading when tested without any load across it, but when the load is reapplied the voltage will drop again rather quickly.
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backwhereubelong

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #8 on: May 16, 2016, 06:27:46 PM »
You can almost take everything Gutbucket says to the bank.  Thanks to his advice over the years I have greatly improved my recordings.  ;D

Offline Gutbucket

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #9 on: May 16, 2016, 06:40:42 PM »
Aw shucks, thanks. Just glad to be of help.
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Offline ilduclo

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #10 on: May 16, 2016, 07:00:02 PM »


To be safe I change the 9V batteries after approximately 12hrs in my two original CA-UGLYs (same circuit as the 9100 I believe) which I use with 4060's.  Low battery voltage causes distortion exactly like you describe. It is first noticeable in the low bass.

 

pretty wasteful, IMO, like I said, I get a year out of my 9v's and that's probably at least 40 hrs.  If you have a tester, don't replace until there's a noticeable drop. Or use rechargeables

backwhereubelong

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #11 on: May 16, 2016, 08:11:04 PM »
I waste batteries maybe, but I replace after them two shows.  It's just not worth messing up a nice recording to save $3-4 dollars.  I only record 22-25 shows a year so spending $36-48 a year on batteries is no biggy.

Offline ilduclo

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #12 on: May 17, 2016, 09:31:41 AM »
There's more to tossing batteries than money loss  :crazy:

Offline Gutbucket

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #13 on: May 17, 2016, 09:38:29 AM »
To be safe I change the 9V batteries after approximately 12hrs in my two original CA-UGLYs (same circuit as the 9100 I believe) which I use with 4060's.  Low battery voltage causes distortion exactly like you describe. It is first noticeable in the low bass.

pretty wasteful, IMO, like I said, I get a year out of my 9v's and that's probably at least 40 hrs.  If you have a tester, don't replace until there's a noticeable drop. Or use rechargeables

A battery box has far, far less current drain than a preamp using an active buffer.  I primarily use rechargables and recharge them after each use, and encourage others to do the same.  However, I need to replace them and have yet to do so, so I'm back to using disposable alkalines in the interim.  Chris Church mentioned 25 hrs or so for the CA-UGLY preamp.  It has no low battery indicator though, so I change them at about 12hrs and have not lost a show due to a low battery since doing that.  I had lost a few prior due to low battery voltage. 

Waste not batteries nor recordings.
Find the middle way.
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backwhereubelong

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Re: Brickwalling with DPA4061 > CA-9100 > Tascam DR-2d (line-in)?
« Reply #14 on: May 17, 2016, 10:00:22 AM »
There's more to tossing batteries than money loss  :crazy:

Before you get splinters by hugging trees and stuff, please re-read my comment.  Did I say I threw them away?  I don't think so.  I said I "replaced" them.  I'm not sure if you know this or not, so let me inform you, there are other things that use a 9 volt instead of just battery boxes.  I have a small recording studio in Georgia and we use them to power active pickups in various guitars.  There is also alarm clocks, flashlights and smoke detectors ...  I keep them in a refrigerator to minimize the drain until I find another use for them, and yes, once they are dead I toss 'em.  Good enough?  ::)
« Last Edit: May 17, 2016, 10:09:42 AM by Roots To Branches »

 

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