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Gear / Technical Help => Ask The Tapers => Topic started by: jkoch on August 20, 2018, 02:20:06 AM

Title: Recording Issue - Please Help!
Post by: jkoch on August 20, 2018, 02:20:06 AM
Recording the tape is fine for about 10 minutes. Both channels hitting a peak of about -25db. Suddenly, the right channel drops to basically nothing at about -60db with cracks and pops and the left channel gets higher in to about -12db with loud tinny sounding hiss. The music is still present under both but completely unsalvageable.

Any clue what may be causing this? The thing that is tripping me out is whenever I start a new recording it's fine for the first 5-10 minutes and then this happens.

Setup is Schoeps MK4 > actives > nbox+ > Edirol HR-9.

I have about 5 days to solve this issue before a big trip where I was planning on taping 6 shows in 10 days.

Thanks!
Title: Re: Recording Issue - Please Help!
Post by: u2_fly_2 on August 20, 2018, 04:20:16 AM
Perhaps a lose connection from the nbox or the wires from the MK4(?)

If you turn around the connected wires, do you get any "drop-outs" or "static noise"?

Record a bit and test different settings/connections and see if you might find out what is causing this. If it´s not anything within some circuit that can´t be spotted.

Hope you find out what´s making this problem.
Title: Re: Recording Issue - Please Help!
Post by: Ronmac on August 20, 2018, 06:56:12 AM
Trouble shoot by using the "divide and conquer" method, i.e. split your chain into distinct "groups" and confirm pass/fail until you find the guilty component(s).

A good start would be to establish if the recorder is faulty. An easy test would be to connect the recorder via a cable to a known good signal source. Ideal would be taking a connection from your laptop to the recorder and generating a white noise signal in Audacity (or other DAW) that can be recorded on the HR-9.

https://www.ghacks.net/2015/03/31/use-audacity-to-generate-and-save-white-noise-audio-files/

If that works OK, move on to checking your input chain to a known good recorder.

Good luck, and let us know what you find, please.
Title: Re: Recording Issue - Please Help!
Post by: rippleish20 on August 20, 2018, 02:23:08 PM

Is the first part of the recording crowd before a song, etc? It's interesting how the issue with the right channel happens at the same time the song starts/sound level goes up....
Title: Re: Recording Issue - Please Help!
Post by: kindms on August 20, 2018, 06:54:44 PM
what is powering the mics ?
Title: Re: Recording Issue - Please Help!
Post by: jkoch on August 20, 2018, 08:41:28 PM
The issue with the left and right are simultaneous. It’s not when music hits. The audio is the same level. The crazy high on one of the additional loud noise in that channel and the other channel gets quieter at the same time. Nothing to do with what is being recorded.

It’s hard to test because I can’t test the mics or pre on their own. The mics have special actives with a joint lemo connector that attaches to the nbox (pre). The nbox has phantom power for the mics.
Title: Re: Recording Issue - Please Help!
Post by: justink on August 20, 2018, 09:00:28 PM
from the thread on FB, i'm guessing it's either the RCA cable (cheap and simple to check, just buy another set on amazon, or dig around in a drawer).

if it's not the RCA...  could it be the single connector or the solder to it?  that's relatively easy to fix too... just send it to someone that does cable work.

¯\_(ツ)_/¯
Title: Re: Recording Issue - Please Help!
Post by: jkoch on August 20, 2018, 10:17:53 PM
Well, not the RCAs.
Title: Re: Recording Issue - Please Help!
Post by: daspyknows on August 20, 2018, 11:46:51 PM
Are you using rechargeables?  If so try fresh 9v's.  Not likely but a cheap part to test.  Can you reproduce at home using loud stereo?
Title: Re: Recording Issue - Please Help!
Post by: jkoch on August 21, 2018, 03:15:35 AM
Are you using rechargeables?  If so try fresh 9v's.  Not likely but a cheap part to test.  Can you reproduce at home using loud stereo?
That's what I've been doing. It's not the RCAs, not the batteries, not the line in. It's either the nbox+, the actives attached to the mic capsules, or the actives extension cable. I tried it without the extension cable so my guess is it's the actives up top, but I suppose it could still be the nbox+ as well or even both active pieces.

Going to send them back to the creator and see how it goes. Hopefully I can get a loaner for my trip.
Title: Re: Recording Issue - Please Help!
Post by: rippleish20 on August 21, 2018, 10:17:32 AM
The issue with the left and right are simultaneous. It’s not when music hits. The audio is the same level. The crazy high on one of the additional loud noise in that channel and the other channel gets quieter at the same time. Nothing to do with what is being recorded.

It’s hard to test because I can’t test the mics or pre on their own. The mics have special actives with a joint lemo connector that attaches to the nbox (pre). The nbox has phantom power for the mics.


I completally misread your initial comment, sorry. I would speculate a Nbox issue (or maybe some sort of active to nbox grounding issue?)