Topic: Recording sounds awful, help with Diagnosis

[rsimms3]

Okay.  The two rigs used:

1. Nak CM300s with Omni caps > CA9100 > iRiver h300. 
2. Nak CM300s with Omni caps > AT Phantom adaptors made from AT915QMRx Podium Mics > PS2 > h300

The common denominator is the mics and iRiver.  The first show was The Verve Pipe and I think the CA9100 was not providing enough juice and have learned since that recording that older CA9100s provide less power and even the new one I am getting from Chris will not provide a full 9v to both mics (beside the point).  Second gig is the Black Crowes.  I figured running the PS2 with adaptors, all would be good.  NOT.  I ran no attenuation, no roll off, and all analog gain with the h300 in both cases.  Did I wire the CM300s wrong?  Is the input on the h300 to blame?  I tried to recreate the issue using the second set up at home but I don't have the SPLs to do it I don't think, besides my neighbor is upstairs right now. 

WAV sample:
http://home.comcast.net/~simms3/WTF.wav

Any help is appreciated, I have only tried to run the Naks twice now and both times came up empty so I really want to figure this out before I move on to new things with the other parts I have.

[Church-Audio]

Okay.  The two rigs used:

1. Nak CM300s with Omni caps > CA9100 > iRiver h300. 
2. Nak CM300s with Omni caps > AT Phantom adaptors made from AT915QMRx Podium Mics > PS2 > h300

The common denominator is the mics and iRiver.  The first show was The Verve Pipe and I think the CA9100 was not providing enough juice and have learned since that recording that older CA9100s provide less power and even the new one I am getting from Chris will not provide a full 9v to both mics (beside the point).  Second gig is the Black Crowes.  I figured running the PS2 with adaptors, all would be good.  NOT.  I ran no attenuation, no roll off, and all analog gain with the h300 in both cases.  Did I wire the CM300s wrong?  Is the input on the h300 to blame?  I tried to recreate the issue using the second set up at home but I don't have the SPLs to do it I don't think, besides my neighbor is upstairs right now. 

WAV sample:
http://home.comcast.net/~simms3/WTF.wav

Any help is appreciated, I have only tried to run the Naks twice now and both times came up empty so I really want to figure this out before I move on to new things with the other parts I have.

The 9100 v 3.0 and above provides 8 volts of plug in power to your mics. More then enough power for the Naks.. What I have seen with the Naks is they do overload pretty easy. My tests show 3% distortion at 114db where as my mics are less then 0.06% at 114 db. The only thing I have never tested is current draw of the Nak mics.

[rsimms3]

Good information, do you suspect overload here?

[Charlie Miller]

I had my naks overload at the 11/3/00 WSP show. I ran the 10db pad the next night and they were fine.

[rsimms3]

That was the only time?  I have only ran them twice and this was an issue both times.  I must have bad luck.  I will run the pad next time and go from there.  Any other opinons/guesses are welcome.

[Church-Audio]

That was the only time?  I have only ran them twice and this was an issue both times.  I must have bad luck.  I will run the pad next time and go from there.  Any other opinons/guesses are welcome.

You are more then welcome to send your mics to me for evaluation I can tell you exactly where they are overloading. And I strongly suggest the 10db pad when ever possible.. Just remember to crank the 9100 The naks are not super hot output mics that's for sure so with the 10 db pad I would suggest running my 9100 at full.
Chris

[Sunday Driver]

I'm definitely no expert...but I do know that my iRiver's input (only 1 input claiming to be "line in"!) is very sensitive. Just this past Sunday, the SDHC hard in my R-09HR corrupted on me, and I got stuck using my old iRiver H120. It was a loud stadium show, recording with AT853 hypers and and a PS-2...the recording has some slight distortion issues. No way would that have distorted using the same mics / power unit and my Edirol R-09HR going line in. It takes a much hotter signal to get decent levels. So, I think the iRiver's sensitive input may have contributed somewhat to your distortion issues. As for what causes this technically...I'm not sure...it could be the difference in impedance?

[bugg100]

I do know that when I ran a full body Tascam pe-120 with a dying battery, it sounded similar to what your bass sounded like....  New battery @ 9.18v and good as new.
I'm looking around for the old battery to measure its voltage, but don't see it right now.

I know Chris says:  "9100 v 3.0 and above provides 8 volts of plug in power to your mics. More then enough power for the Naks.."
My v2 9100 puts out around 5.7v (from memory, don't kill me if I'm wrong) which I know was LESS than the battery that was a failure...

For what it's worth, seems like a loud stereo test with bass heavy material would be plenty loud to test with...

I'm afraid that with my older 9100 I may be out of luck on modded "naks", which sucks cause I have the materials to make a screw on back end for the cap and atten. to avoid any "mod" at all for low profile things.....

[rsimms3]

The sample above was using a PS3 with phantom adaptors, the PS2 had a brand new, out of package Energizer 9v battery in it.  The low battery light never came on while using it and doesn't come on now using it.  I know for a fact that the light works because I drained a 9v before running full 48v out of the PS2. 

My other question is, how will the 10db pad help with this situation?  The signal wasn't too hot, it was distorted.  Does the pad do more than just reduce the volume?  Similar to a 4.7k mod?

[Church-Audio]

I do know that when I ran a full body Tascam pe-120 with a dying battery, it sounded similar to what your bass sounded like....  New battery @ 9.18v and good as new.
I'm looking around for the old battery to measure its voltage, but don't see it right now.

I know Chris says:  "9100 v 3.0 and above provides 8 volts of plug in power to your mics. More then enough power for the Naks.."
My v2 9100 puts out around 5.7v (from memory, don't kill me if I'm wrong) which I know was LESS than the battery that was a failure...

For what it's worth, seems like a loud stereo test with bass heavy material would be plenty loud to test with...

I'm afraid that with my older 9100 I may be out of luck on modded "naks", which sucks cause I have the materials to make a screw on back end for the cap and atten. to avoid any "mod" at all for low profile things.....

FYI I do offer a upgrade program for $100 + return shipping I rebuild your old 9100 * basicly replace all of the parts with the exception of the case. So you will be getting a brand new preamp.

Chris

[Sunday Driver]

My other question is, how will the 10db pad help with this situation?  The signal wasn't too hot, it was distorted.  Does the pad do more than just reduce the volume?  Similar to a 4.7k mod?

Personally, I DO think that a 10db pad will help you when using your gear with the iRiver; at least when using your Naks with the PS-2. Not sure about the preamp.

[sunjan]

I'm definitely no expert...but I do know that my iRiver's input (only 1 input claiming to be "line in"!) is very sensitive. Just this past Sunday, the SDHC hard in my R-09HR corrupted on me, and I got stuck using my old iRiver H120. It was a loud stadium show, recording with AT853 hypers and and a PS-2...the recording has some slight distortion issues. No way would that have distorted using the same mics / power unit and my Edirol R-09HR going line in. It takes a much hotter signal to get decent levels. So, I think the iRiver's sensitive input may have contributed somewhat to your distortion issues.

Hmm, the sensitivity of the iriver shouldn't be a problem as long as you monitor your levels and see that they don't peak into the +0dB domain. rsimms3, did you use the Rockbox safety clip feature? That would at least rule out overloading the iriver.

Also, can you clarify if your naks are stocks or modded - in that case how? Normally, you should be powering them with an internal 9V battery, but they are fairly tolerant, according to Roger Gustavsson here on TS. According to his research, powering them with 7.2V (2x 3.6V 1/2AA batteries) should be sufficient for most situations. On the high voltage end, up to 12V won't do them any harm...

How is the cabling to the CA9100 done? 3-wire with either 2x miniXLR or 2x TRS 1/8"?

If you're in doubt about the CA9100 mic power, you should be able to measure it with a multimeter...

[rsimms3]

The Naks are modded with just a mini XLR in the attenuator body.  The unit was not overloaded, it clipped during the show only rarely, the above WAV sample is an unaltered slice of a part of a song.  I haven't had an opportunity to check out the Naks in front of the stereo at full volume, I should go check if the neighbor is home.

Here is a link to the thread where I outlined how I modded them, as I mentioned earlier, maybe I wired the attenuators wrong.

http://taperssection.com/index.php/topic,103715.0.html

[bugg100]

Maybe you should pull it apart and trace your wiring job versus an unmodded attenuator (guess you have one or two of those, huh? ) and if the wiring is correct, try to run the modded part while NOT reassembled.  That would help with cold solder joints on wires and wierd ground problem (or shorts).

Also, did you deflux the board with 91% alcohol after you resoldered things?  That is recomended procedure on building stuff that I have put together...  Keep us posted.

Joe

p.s. I think you should be testing only with the samson adapters and ps-2... Voltage where you know it is within spec!  The -10dB pad shouldn't be what is needed. If it was EVERY tape I have pulled for the last 6 months would sound like your sample....  But, it can't hurt to elimanate it as a cause!