Unbalanced Polarity Flip

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Drone
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Re: Unbalanced Polarity Flip

Post by Drone » Wed Sep 05, 2018 1:53 pm

Ta guys.

Tony, unfortunately it's not a mic, it's the same line level signal that gets split multiple times in various signal chains and then mixed back together.

I guess I just need to find a new inexpensive source of transformers, I wish Weber still had that little one they had for DI's out at about $5 or so.

Maybe I have something kicking about.

I like the delay idea, I should have thought of that, I also think I have a crossover with delay somewhere, because it will have to be a really small delay won't it? Like 1/2 wavelength of whatever frequency I think is affected?
The previous statement is from a guy who records his own, and other projects for fun. No money is made.

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Re: Unbalanced Polarity Flip

Post by drumsound » Wed Sep 05, 2018 3:31 pm

I'm Painting Again wrote:
Wed Sep 05, 2018 10:05 am
Drone wrote:
Tue Sep 04, 2018 7:40 am
I'm Painting Again wrote:
Wed Aug 08, 2018 7:46 pm
ya seems like you don't have multiple phases to flip - just the one phase plus ground coming in on the unbalanced line

what are you hoping to achieve ?
I try not to say phases, isn't that a bunch of peoples pet peeve when you confuse polarity and phase? But yeah, I'm looking for 180 degree phase shift, so that when the wave goes up, the signal goes down, kind of thing.

The problem is, I have a signal split into multiple signal chains, and then mixed back together, but one particular chain seems to cause the low end to disappear when added in, so I wanted to try inverting the polarity to see if that improved things. I don't have a fancy phase adjustment tool, and I can't do it in the box.
phases is appropriate here - phases don't exist to flip on unbalanced lines - - you have two phases in relation to ground on a balanced line

first thing I'd do is go over how everything is wired and the types of inputs and outputs on the devices in your signal path - are you mixing unbal and bal devices ? wrong wiring could be causing your problem in that case

if you know everything is connected correctly - try a simple delay in the path first and see if you can get a change in your low end by delaying it against the rest

might give you a clue that it's actually a polarity or phase issue

as for a polarity flipper in that situation and
I dunno if this will work but maybe try this …

the ebtech line level shifter will balance an unbalanced line (also change its operating level - so watch overloading your next piece of gear) the output can be wired to a switch (like the Shure A15PRS) to swap pins 2 and 3 to another line that's carrying ground or one of the polarities off the switch to the next unbalanced input



so it'd be like unbalanced cable (TS) from unbalanced output to the -10 in on ebtech then +4 output on ebtech to a balanced cable TRS wired to XLR -to the [Shure switch] - then - XLR out of Shure switch to cable wired XLR pin 1 to Sleeve / XLR pin 2 to Tip

if this works its probably possible to DIY with parts more inexpensively









*
I think this is really good advice. I'm guessing there's an odd cable or maybe one of the piece pf the chain is wired goofy from the factory.

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Re: Unbalanced Polarity Flip

Post by I'm Painting Again » Thu Sep 06, 2018 6:08 am

thanks that's the most simple and easy method of operation I could think of..

I do a lot of connection between unbal and bal and unconventional wiring as I have a mix of types and ages of gear I like

noticed something completely insane yesterday setting up a Fearn VT-2 with a TEAC 1/4"-4 machine

if I just left out the ebtech transformer and wired directly from the XFRMR bal output of the VT-2 to the RCA unbal in on the TEAC the result would be that if the VT-2's VU meter was switched on I'd get a louder more harmonically rich output on the TEAC - with the VU meter turned off I'd get a thin lower level signal reaching the TEAC

add the ebtech transformer it operates normally

but that's testament to how wacky the world gets when you mate devices that are not meant to work together - the VU meter on/off switch for goodness sake

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Re: Unbalanced Polarity Flip

Post by Matt C. » Thu Sep 06, 2018 11:10 am

I'm Painting Again wrote:
Thu Sep 06, 2018 6:08 am
with the VU meter turned off I'd get a thin lower level signal reaching the TEAC
Usually this is a sign of a transformer coupled output that has one side of it's output floating. If you're connecting a transformer output to an unbalanced input you generally need to ground the (-) phase instead of just letting it hang out (like you can do with electronically balanced outputs). Maybe switching the VU meter into the circuit creates a connection to the (-) phase that isn't usually there.

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Re: Unbalanced Polarity Flip

Post by I'm Painting Again » Sun Sep 09, 2018 8:09 am

Matt C. wrote:
Thu Sep 06, 2018 11:10 am
I'm Painting Again wrote:
Thu Sep 06, 2018 6:08 am
with the VU meter turned off I'd get a thin lower level signal reaching the TEAC
Usually this is a sign of a transformer coupled output that has one side of it's output floating. If you're connecting a transformer output to an unbalanced input you generally need to ground the (-) phase instead of just letting it hang out (like you can do with electronically balanced outputs). Maybe switching the VU meter into the circuit creates a connection to the (-) phase that isn't usually there.
That sounds like it's probably right

Do you know if that can cause damage to the transformers, etc?

I'm asking as it actually provided a pretty cool flavour for certain stuff - It wasn't a bad effect

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Re: Unbalanced Polarity Flip

Post by Matt C. » Sun Sep 09, 2018 9:43 am

I'm Painting Again wrote:
Sun Sep 09, 2018 8:09 am
That sounds like it's probably right

Do you know if that can cause damage to the transformers, etc?

I'm asking as it actually provided a pretty cool flavour for certain stuff - It wasn't a bad effect
No it won't damage anything.

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Re: Unbalanced Polarity Flip

Post by Scodiddly » Mon Sep 10, 2018 5:40 pm

I'm Painting Again wrote:
Wed Sep 05, 2018 10:05 am
phases is appropriate here - phases don't exist to flip on unbalanced lines - - you have two phases in relation to ground on a balanced line
It's polarity in this case. Phase refers to time delay, measured in degrees at a specific frequency. Which makes it kind of hard to pin down when there are a whole bunch of frequencies.

Electricians refer to different phases of 3-phase power, which is actually true because you have 60Hz (or 50Hz, depending on where you live) delayed by 120 and 240 degrees relative to the first phase. Most homes are wired with single phase power, which is center-tapped to provide two opposite-polarity legs.

When you balance a signal you don't get two phases, you get a signal and then you get a polarity-inverted signal.

I'm a well-known fussbudget when it comes to terminology. Don't get me started on podium vs. lectern.

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Re: Unbalanced Polarity Flip

Post by floid » Tue Sep 11, 2018 5:12 am

Had to think about that for a minute but makes sense. The physical rotation of the generator creates the delay in 3 phase. Center tapping a winding is just some electrical trickery with a single phase.
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Re: Unbalanced Polarity Flip

Post by Scodiddly » Tue Sep 11, 2018 5:40 am

floid wrote:
Tue Sep 11, 2018 5:12 am
Had to think about that for a minute but makes sense. The physical rotation of the generator creates the delay in 3 phase. Center tapping a winding is just some electrical trickery with a single phase.
If you have an electric stove in your home then it runs on balanced power. :lol:

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Re: Unbalanced Polarity Flip

Post by I'm Painting Again » Wed Sep 12, 2018 5:28 pm

Scodiddly wrote:
Mon Sep 10, 2018 5:40 pm
I'm Painting Again wrote:
Wed Sep 05, 2018 10:05 am
phases is appropriate here - phases don't exist to flip on unbalanced lines - - you have two phases in relation to ground on a balanced line
It's polarity in this case. Phase refers to time delay, measured in degrees at a specific frequency. Which makes it kind of hard to pin down when there are a whole bunch of frequencies.

Electricians refer to different phases of 3-phase power, which is actually true because you have 60Hz (or 50Hz, depending on where you live) delayed by 120 and 240 degrees relative to the first phase. Most homes are wired with single phase power, which is center-tapped to provide two opposite-polarity legs.

When you balance a signal you don't get two phases, you get a signal and then you get a polarity-inverted signal.

I'm a well-known fussbudget when it comes to terminology. Don't get me started on podium vs. lectern.
are you purposely trying to not confuse people or something?

ya polarity is the better descriptor for sure - they say there's no delay between the + and - on a balanced line

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Re: Unbalanced Polarity Flip

Post by vvv » Wed Sep 12, 2018 10:02 pm

I think yer all just, eh, goin' thru a phase.

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