Teac Model 5 mic preamp phase?

lonewhitefly

Active member
i understand the mic preamps on the Teac 5 board are wired "pin 3 hot" on the XLR. i have always used standard "pin 2 hot" XLR cables without any noticable problems. should i be using XLRs with "pin 3 hot" because the rest of the board is unbalanced (RCA outs). or is it fine with regular cables since the in/out on the XLR is balanced?
 
Its not the cable that matters, and you really don't need to worry about it on a mic input. Balanced line outs and ins is where it may get hairy depending on what you are interfacing, but the mic signal becaomes unbalanced once it gets into the board. You're fine with just a regular old mic cable.
 
The XLR Cable has nothing to do with it , its the Preamp that has pin 3 hot .....

There is no problem running it the way you have it , Phaze is only a problem when you mix in-Phaze and out-of-Phaze tracks ,so if all the tracks you are useing are coming from the board then all the Tracks are in phaze with each other so there is no problem ....

There would be a problem if you were recording from the Teac and another Board or source that has pin 2 hot , in that case you would need to switch pin 2 and pin 3 on one end of the xlr cable to keep phaze with the other Board/Source ....


PS: there is also a possibility that Pin 3 is hot because the internal circuitry inverts the Phaze before the output therefor keeping normal phaze .....
 
awesome, thanks for the replys. i read a few things about "total polarity" and got somewhat concerned finding out the board was "pin 3 hot" but i don't fully understand this stuff! i always assumed "if it sounds good, it is good", which is probably more true than not true anyway! but a tech told me something about if the total polarity wasn't right there would be some kind of issue where the speaker cone comes toward the listener instead of retracting so i thought this might have something to do with it. it did have to do with line signals though, not mic, so perhaps that is where i am getting confused.
 
Are you using any outboard preamps n stuff?

Just keep all that in mind...that way if you do, just pick one or the other, and do a reverse. A simple conversion cable can do the trick...just take the wires soldered to pins 2 & 3 and reverse them...*only at one end* of the cable.
That cable can now be used to "flip" whatever you need to flip.
Maybe have two of them on hand...so you can cover stereo signals...etc.

If you are recording from the board into a DAW...then it's no biggie...most DAW apps have a simple phase reverse switch (actually, we are talking about polarity here, not phase).

My TASCAM 3500 was all Pin 3 hot...I ended up just reversing it internally on all its balanced lines....I just didn't ever want to think about it. :)
 
well, most of my stuff is unbalanced, so its not usually an issue except for mic preamps. the board has RCA line ins and RCA outs, so if i use an outboard preamp/compressor, i just use the unbalanced 1/4" out right into the tape machine. then i mix through the board going line in via RCA. i use the preamps in the board 99% of the time anyway but i may be using some other preamps in the future but i go directly to tape if i do. if i send something out to a compressor or de-esser, submixer, etc, after recording, i always use unbalanced 1/4" to RCA back into the line ins on the board.

when i mix, its each track of the tape machine through the RCA lines in the board, then out from the board into a tube compresser via RCA to 1/4", then out to another 1/4" to RCA into the tape machine for mixdown. then out to a CD burner via RCA for the final transfer.

its all pretty much 70s teac-type stuff, so i figured i was alright keeping it simple.

PS - i never record any individual tracks in stereo!
 
i did just think of one potential issue, i record the bass direct sometimes, through a whirlwind EDB1 direct box. 1/4" in to XLR out into the teac mic preamp, still using the same regular xlr cable. would this cause a polarity issue or is it the same as a mic?
 
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Na...same difference.
Since everything that you use balanced lines for goes through the Model 5...it's all going to get the same polarity flip...so it's not an issue.
Only if you say...had an outboard preamp (or other device) that was Pin 2 hot...then whatever you ran through it would be reversed from the stuff going through the Model 5.
That's when a conversion cable would take care of things by also flipping that device to match the Model 5.
You just pick one polarity and make sure everything follows it...+ or -...as long as it's all the same.
 
but i can still use the pin 2 hot external preamp xlr and then send the UNbalanced out from that to the tape machine, back through the model 5 to mixdown, it would not be an issue since the output is unbalanced, right? similarly, sometimes i use the mic preamp in the model 5 and send it to an external compressor, but the send out is unbalanced RCA to 1/4" on the comp, and out from the comp 1/4" to RCA back to the model 5. so i don't see how this could be an issue since its all unbalanced at that point.

i guess what i'm trying to say is as long as everything external ultimately goes through the tape machine and the model 5 unbalanced in and out, i don't understand how i would need the polarity reversed cable. the only exception would be the microphones and bass DI which go directly into the model 5, which we've already worked out is ok.

i think i understand now! thanks for the help

ps - the tape machine is all rca ins and outs (unbalanced)
 
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i just figured out i was confusing relative phase w/ absolute phase in my initial question. we have been talking about relative phase, but i was initially concerned with absolute phase. so, i guess technically, if your pins are not the same, then your absolute phase will not be correct. but apparently it may never be correct anyway (or may not be able to even be measured) according to this article:

http://www.sweetwater.com/expert-center/techtips/d--04/16/1998

more info:

http://www.sweetwater.com/expert-center/techtips/d--12/23/1999

http://www.stevehoffman.tv/forums/archive/index.php/t-116990.html

http://www.stevehoffman.tv/forums/archive/index.php/t-197358.html

its really audiophile stuff, and i've always been more lo fi anyway!
 
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i think i may have figured this out ...

everything that is unbalanced does not matter, it already has "correct" polarity (for instance, a mic placed in frony kick drum moves forward from the speaker instead backward into the speaker when playing back) inherently since it is "hot" only.

when using a balanced line, if i use a "pin 2 hot" connector into a "pin 3 hot" input, i have a reversal. so all of my line signals going in are going to have a reversed polarity from all of my mic preamp signals!

if i use an external preamp, "pin 2 hot" with a "pin 2 hot" xlr, then go into the tape machine, the polarity will be correct. but then it will be mixed with my other tracks, some of which are correct (the ones that began as direct lines) and some of which are incorrect (the ones that began as mic/xlr).

so the only way for all of it to be correct polarity is to use "pin 3 hot" wired xlr, or use adapter cables like the previous poster suggested.

but after researching this issue, i am not sure that i care if the polarity is correct or not. it seems that in the 1960s (and before) and even into the '70s, there was no standard so "pin 2 hot" and "pin 3 hot" were used interchangably. for instance, if you recorded some tracks on an ampex machine, then played that tape back on a studer and overdubbed more tracks, you would have some tracks with correct polarity and some tracks with incorrect polarity.

of course, it also depends on how you recorded it in the first place. if you placed a mic on the drummer's side of the kick, the attack would recede from the speaker. if you reverse the polarity, the speaker would move forward.

i have no idea what happend if the mic was at the side of the kick!!!
 
i am not sure that i care if the polarity is correct or not.

Probably the only time you would...is if you recorded like say...a guitar with two mics...one going through the Model 5 and another going through an outboard preamp...and then both going to some third device where everything stayed balanced.

What would happen is...off of one mic the guitar signal would begin from the positive "up" side of the wave cycle, and on the other from the negative "down" side of the cycle.

If you then combined them...you would get frequency cancellations and comb filtering....and a rather hollow-ish sound.
Most people would be able to hear this and know that something was wrong...but there are times when two reversed polarity signals would not be quite noticeable, and since they are not perfect reverse images of each other (two different mics/pres)...they would not completely cancel out, but would just sound kinda weak and "empty"...it could get by in a busy mix which would only make you go nuts trying to EQ-fix what was a simple polarity issue.

But hey...you seem to have gotten a solid grip on the whole thing...so I don't think you need to worry about anything! :)
 
yes, steve hoffman says that most multi-track recordings are about 50/50 in terms of "correct" absolute polarity ... with different sources within the same songs, etc.

i rarely (almost never) use more than one mic on a source (except maybe 2-3 on drums) and i rarely (almost never) use external mic preamps!

thanks for your help while i worked all of this through my head! ...
 
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