boji

Φ--- faceplate symbol for polarity?
« on: January 12, 2019, 07:02:37 PM »
I've heard a few people correct those who say phase when they mean polarity.  Might someone care to shed some light on the distinction when coming off a transformer?

I like the 'Phi' symbol. Nice and stout, and would look good for polarity flip button.   ;D


Brian Roth

Re: Φ--- faceplate symbol for polarity?
« Reply #1 on: January 12, 2019, 08:13:36 PM »
Back when I used to rack console modules:

http://www.brianroth.com/custom/custom.html

...I wrestled in my mind with that label, and decided to use POL REV as the legend.  But, occupies a lot more panel space.

Bri

Brian Roth Technical Services
Salina Kansas, home of the best vinyl on the planet!

http://www.BrianRoth.com
recordingservicesandsupply.com/
www.qualityrecordpressings.com/
store.acousticsounds.com

JohnRoberts

Re: Φ--- faceplate symbol for polarity?
« Reply #2 on: January 12, 2019, 08:53:48 PM »
I've heard a few people correct those who say phase when they mean polarity.  Might someone care to shed some light on the distinction when coming off a transformer?

I like the 'Phi' symbol. Nice and stout, and would look good for polarity flip button.   ;D
We've had this discussion here before too...  ::)

Phi is cute and fits on tight faceplates, but might not be understood by everybody (important IMO).  :-[

Phase is well understood but not accurate, so irritates people like me.   >:(

Polarity is hard to fit in, but correct.  8)

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

MountCyanide

Re: Φ--- faceplate symbol for polarity?
« Reply #3 on: January 12, 2019, 09:39:55 PM »
How about :
<--
-->

john12ax7

Re: Φ--- faceplate symbol for polarity?
« Reply #4 on: January 12, 2019, 10:16:26 PM »
Phase by itself is ambiguous.  How many degrees of phase shift and at what frequency? Polarity is well defined,  a reversal of + / -, reversal of hot / cold,  180 degree shift at all frequencies.

For labeling phase,  polarity,  pol,  phi are all common.  Use what you like.

pucho812

Re: Φ--- faceplate symbol for polarity?
« Reply #5 on: January 12, 2019, 10:17:47 PM »
I prefer

Pol in
Pol out.

Either you are at 0 degrees or 180 out.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

iampoor1

Re: Φ--- faceplate symbol for polarity?
« Reply #6 on: January 12, 2019, 11:42:51 PM »
Phase by itself is ambiguous.  How many degrees of phase shift and at what frequency? Polarity is well defined,  a reversal of + / -, reversal of hot / cold,  180 degree shift at all frequencies.

For labeling phase,  polarity,  pol,  phi are all common.  Use what you like.

I don't think phase is particularly ambiguous in this context, since it is assumed to be 180degrees of phase shift across the entire audio band, unless there is a Mic pre phase/polarity switch that intentionally doesn't do that.  ;D

JohnRoberts

Re: Φ--- faceplate symbol for polarity?
« Reply #7 on: January 13, 2019, 12:31:04 AM »
I don't think phase is particularly ambiguous in this context, since it is assumed to be 180degrees of phase shift across the entire audio band, unless there is a Mic pre phase/polarity switch that intentionally doesn't do that.  ;D
Back last century I labelled the switch "phase" because polarity didn't fit in the panel space I had available, while in the owner's manual copy I described the switch function properly as "reversing absolute polarity" . 

IMO the larger sin is not being easily understood, even by casual users. Phi is cute, but if you have to explain what it means, you failed at labelling the controls. Phase despite being inaccurate is likely to be interpreted correctly by operators looking to change that signal relationship. 

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

boji

Re: Φ--- faceplate symbol for polarity?
« Reply #8 on: January 13, 2019, 02:39:30 AM »
How polarizing a topic.  /honk

I just wanted a bit of chiding to get my right brain to let go of this one.

POL it is.

Nice rackups Mr. Roth!

Confusion for the newb might invite experimentation. Or fear paralysis.  ???

boji

Re: Φ--- faceplate symbol for polarity?
« Reply #9 on: January 13, 2019, 02:41:52 AM »
Thanks for the suggestion, Mt. C.  Turns out I'm already using that symbol for slot swap!


Brian Roth

Re: Φ--- faceplate symbol for polarity?
« Reply #10 on: January 13, 2019, 03:20:40 AM »
How polarizing a topic.  /honk

I just wanted a bit of chiding to get my right brain to let go of this one.

POL it is.

Nice rackups Mr. Roth!

Confusion for the newb might invite experimentation. Or fear paralysis.  ???

Thanks!

Those projects were from a long time ago before a bunch of other folks began hanging modules from a piece of angle iron with  XLR's dangling from the back side, for far less money.  I just shrugged and moved on because  I refuse to deal with junk projects and fight with "so and so will rack this for $4.95 and can you match that price?"

I grew up in another time when pro audio equipment was built to a higher standard.  Quoting Tom Petty "I won't back down and I'll Stand  My Ground"  <g>

Glad to be semi-retired from much of the BS! 

Back to my choice of legends....switch flipped UP engaged that function, just as the overhead light in the kitchen went ON in the Up position.

Bri


Brian Roth Technical Services
Salina Kansas, home of the best vinyl on the planet!

http://www.BrianRoth.com
recordingservicesandsupply.com/
www.qualityrecordpressings.com/
store.acousticsounds.com

weiss

Re: Φ--- faceplate symbol for polarity?
« Reply #11 on: January 13, 2019, 10:09:34 AM »
The question is, why would someone want to change the phase to something different  than 180 degrees?

scott2000

Re: Φ--- faceplate symbol for polarity?
« Reply #12 on: January 13, 2019, 10:34:56 AM »


Edit////different than 180/////doh
« Last Edit: January 13, 2019, 11:52:38 PM by scott2000 »

JohnRoberts

Re: Φ--- faceplate symbol for polarity?
« Reply #13 on: January 13, 2019, 11:52:37 AM »
The question is, why would someone want to change the phase to something different  than 180 degrees?

For one example in loudspeaker crossovers the "phase" response of 3 pole filter alignments do not create a dip or null at crossover point, like older 2 pole alignments did. Those old 2 pole crossovers required a polarity switch on one output so you could flip one output opposite polarity to prevent the 180' (degree) out of phase suck out at the crossover point (confused yet?). The modern 4 pole crossover alignment that is now popular rotates that phase a full 360' (degrees) so back in phase again (at least for persistent sine waves).
-------
Other popular studio/guitar effects like Phasors intentionally create a comb filter using phase shift.
----------
I believe one studio product manufacturer included an adjustable phase (yes phase) knob on his preamp so the user could presumably reduce comb filtering from two mics on a drum kit picking up the same signal with different path delay, or whatever... I prefer setting the mics up properly (or using less mics).  ::)

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

boji

Re: Φ--- faceplate symbol for polarity?
« Reply #14 on: January 13, 2019, 12:30:16 PM »
We could just go 'all in':


JohnRoberts

Re: Φ--- faceplate symbol for polarity?
« Reply #15 on: January 13, 2019, 01:09:56 PM »
With the luxury of that much panel real estate, and for your own use, label it whatever you want.  :P

I typically had 4 switches in that immediate area (pad, polarity, phantom, mic/line) and less space available.  Plus I had to be easily understood by paying customers, and their customers.

The greek alphabet existed back then, and even "pol" is not immediately grasped as short for polarity by all. Most experienced operators could figure out even an unlabelled button from proximity and context where it is located.  8)

Some exotic brands might even prefer the obscure phi nomenclature.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

pucho812

Re: Φ--- faceplate symbol for polarity?
« Reply #16 on: January 13, 2019, 01:27:13 PM »
Back last century I labelled the switch "phase" because polarity didn't fit in the panel space I had available, while in the owner's manual copy I described the switch function properly as "reversing absolute polarity" . 


JR
Oh how about a rap button?
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

boji

Re: Φ--- faceplate symbol for polarity?
« Reply #17 on: January 13, 2019, 03:44:03 PM »
"reversing absolute polarity"

Quote
Oh how about a rap button?
;D

Hiphop purists might get insulted. Too 'industry', that word, rap.  8)

scott2000

Re: Φ--- faceplate symbol for polarity?
« Reply #18 on: January 13, 2019, 03:52:30 PM »
Word

JohnRoberts

Re: Φ--- faceplate symbol for polarity?
« Reply #19 on: January 13, 2019, 06:05:27 PM »
Oh how about a rap button?
Even more obscure.....  ;D

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.


 

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