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Gear / Technical Help => Ask The Tapers => Topic started by: Phil Zone on January 20, 2014, 08:12:22 PM

Title: One channel out of phase
Post by: Phil Zone on January 20, 2014, 08:12:22 PM
Hi

So I have a perplexing situation. I taped tab benoit on Friday and used 4 mics one of which is out of phase. What would cause this? It's the first time I ran my ck61 caps and used a set of cables for the first time. But the cables are from Ted and I seriously doubt that he may have flipped a wire somewhere. Any ideas?
Title: Re: One channel out of phase
Post by: bombdiggity on January 20, 2014, 08:27:29 PM
I'm leaning toward the cable.  I have a set (of his) that did that.  I haven't addressed it since they weren't particularly expensive but I'm sure it's the cable. 
Title: Re: One channel out of phase
Post by: Phil Zone on January 20, 2014, 08:31:46 PM
I'm leaning toward the cable.  I have a set (of his) that did that.  I haven't addressed it since they weren't particularly expensive but I'm sure it's the cable.

Any way I can test that, I don't want to bother Ted if I can do it myself. I have a multi meter that should be able to do it, just not sure which setting to use.
Title: Re: One channel out of phase
Post by: willndmb on January 20, 2014, 09:10:11 PM
I'm leaning toward the cable.  I have a set (of his) that did that.  I haven't addressed it since they weren't particularly expensive but I'm sure it's the cable.

Any way I can test that, I don't want to bother Ted if I can do it myself. I have a multi meter that should be able to do it, just not sure which setting to use.
just record your stereo and swap the cables around
If the out of phase follows the cable you know that's the issue
Title: Re: One channel out of phase
Post by: it-goes-to-eleven on January 20, 2014, 09:28:46 PM
Any way I can test that, I don't want to bother Ted if I can do it myself. I have a multi meter that should be able to do it, just not sure which setting to use.

Use the continuity, or ohms setting.  You are measuring the conductance, and verifying that the pins at each end are connected.  That should allow you to zero in on it.  It helps if you can secure both ends of the cable, freeing up both hands to handle the probes.  Or use clips, if they will fit.

If not, trial and error testing with careful documented swapping is the way.


Title: Re: One channel out of phase
Post by: Phil Zone on January 20, 2014, 10:08:44 PM
Any way I can test that, I don't want to bother Ted if I can do it myself. I have a multi meter that should be able to do it, just not sure which setting to use.

Use the continuity, or ohms setting.  You are measuring the conductance, and verifying that the pins at each end are connected.  That should allow you to zero in on it.  It helps if you can secure both ends of the cable, freeing up both hands to handle the probes.  Or use clips, if they will fit.

If not, trial and error testing with careful documented swapping is the way.

I tested every cable except RCA to xlrs. Every one came up fine. Though one had a very high resistance around the 20-30 ohm where the others were around .2-.5 any other ideas?
Title: Re: One channel out of phase
Post by: Phil Zone on January 20, 2014, 10:21:09 PM
Just found a cable that had the wires switched, that's a real easy fix, thanks for the help.
Title: Re: One channel out of phase
Post by: page on January 20, 2014, 10:59:35 PM
Yeah, most times it's a cable issue. Occasionally it's a gear issue (the V3s had a polarity issue on certain serial numbers and they did a recall), and even rarer; on the mic itself (I once saw a mic that had a bad pin-out on the XLR connector, like someone at the factory had soldered the wrong hot/cold pins). Always start with the cables though.
Title: Re: One channel out of phase
Post by: DSatz on January 21, 2014, 08:36:02 AM
Just for the record, the issue with the Lunatec V3s was that both channels were polarity-inverting at the same time. That's not terribly unusual, unfortunately, and didn't cause anyone to make recordings with the channels inverted relative to each other. However, many engineers prefer to preserve correct absolute polarity because some people, with some program material, can hear the difference and the inverted polarity lowers the realism for them. I had Grace rewire my V3 and thought it was to their credit that they handled the situation the way they did.

--Phil, just want to remind you to fix or set aside the cable that had the extra resistance. You didn't say which pin that was on, but it's bad news anywhere.

--best regards
Title: Re: One channel out of phase
Post by: Phil Zone on January 21, 2014, 08:58:47 AM
Any way I can test that, I don't want to bother Ted if I can do it myself. I have a multi meter that should be able to do it, just not sure which setting to use.

Use the continuity, or ohms setting.  You are measuring the conductance, and verifying that the pins at each end are connected.  That should allow you to zero in on it.  It helps if you can secure both ends of the cable, freeing up both hands to handle the probes.  Or use clips, if they will fit.

If not, trial and error testing with careful documented swapping is the way.

30 ohms sounds like you are measuring two wires that are on the opposite side of a transistor.  Was that the cable with the wires swapped?

I tested every cable except RCA to xlrs. Every one came up fine. Though one had a very high resistance around the 20-30 ohm where the others were around .2-.5 any other ideas?

No it was just a microphone cable I was testing, from pin to pin, not the wire. Should that be of concern Jon?
Title: Re: One channel out of phase
Post by: page on January 21, 2014, 10:52:47 AM
Just for the record, the issue with the Lunatec V3s was that both channels were polarity-inverting at the same time.

As I was typing that I kept going "maybe it was just the ADC stage, cause I remember some people didn't care, so it couldn't have been that noticable" but that makes sense; you'd only catch the defect if you were super sharp, lucky, or mixing it the output with something else. Thanks for the correction.

Title: Re: One channel out of phase
Post by: Phil Zone on January 21, 2014, 01:35:21 PM

No it was just a microphone cable I was testing, from pin to pin, not the wire. Should that be of concern Jon?

Maybe.  Sometimes oxidation on the tip of a connector will cause a high reading, but it's not actually high resistance when patched with another connector.  Try cleaning the tip and retest.

How do you recommend going about doing the if its oxidized?
Title: Re: One channel out of phase
Post by: Phil Zone on January 21, 2014, 09:06:42 PM
Thanks Jon. It's a new cable only maybe 6 months or so. It's gotten wet a few times though. We will see
Title: Re: One channel out of phase
Post by: Phil Zone on January 21, 2014, 09:22:10 PM
Would deox work for that? I don't have all of the sprays and would love to only have to get one. Thanks
Title: Re: One channel out of phase
Post by: earmonger on January 31, 2014, 02:17:04 AM
"Mate several times with a female" is a good prescription regardless.