Just when I thought I had it "right"......

[stellavox]

Was "auditioning" a new playback head in a Technics 1500 headbock. A/B'ing IT versus the stock Bogen in my MCI. Using a dub of the Four Seasons (Handel vs Frankie Valli) that I knew had very good imaging, especially depth. Imaging on the "new" head was definitely "restricted" front to back. Chalked that up to the head until I thought - hey, I've experienced this with absolute phase on my Quads before. Maybe it's a phasing issue. Swapped the leads to the speakers and the depth was restored. I must have connected the new head in reverse phase with the "stock" Bogen.

Takeaway from this is a question and a comment. The question involves if there was/is any kind of "standard" regarding tape deck phasing? Can't say I ever heard of one. Comment is maybe that absolute phase switch on the preamp IS useful.

Cheers

Charles

 

[Ki Choi]

Was "auditioning" a new playback head in a Technics 1500 headbock. A/B'ing IT versus the stock Bogen in my MCI. Using a dub of the Four Seasons (Handel vs Frankie Valli) that I knew had very good imaging, especially depth. Imaging on the "new" head was definitely "restricted" front to back. Chalked that up to the head until I thought - hey, I've experienced this with absolute phase on my Quads before. Maybe it's a phasing issue. Swapped the leads to the speakers and the depth was restored. I must have connected the new head in reverse phase with the "stock" Bogen.

Takeaway from this is a question and a comment. The question involves if there was/is any kind of "standard" regarding tape deck phasing? Can't say I ever heard of one. Comment is maybe that absolute phase switch on the preamp IS useful.

Cheers

Charles

Interesting subject, Charles.

In my limited experience, I find out-of-phase signal output on a machine during the initial azimuth testing. Usually it will be a well used machine that heads were replaced in a hurry by a studio tech and the head would be wired reverse. I see the 180 deg out of phase Lissajous Patterns immediately even at the rough 8Khz test tone.

With the out of phase repro head, there will be no imaging to speak of... I would record pink noise and play it back on a properly finished machine, and it is eerie to my ears to hear the small "ball" of noise floating in between the speakers that would be spread out widely across in between the speakers before getting the repro head output in phase. Fun stuff indeed.

Ki

 

[RBFC]

Very interesting! Raises the question of how many systems have some sort of phase/connection error somewhere in the chain!

Lee

 

[Ki Choi]

Very interesting! Raises the question of how many systems have some sort of phase/connection error somewhere in the chain!

Lee

Lee, the issue I had described above is more common on 4 track consumer machines. Have two Akai machines that came with near 90 deg out of phase repro heads...

Ki

 

[stellavox]

Ki, please understand that

I am talking about 180 degree phase reversal on BOTH channels - not one channel out of phase with the other. To my ears, the result has to do with the degree of the "illusion of (amount of) depth" and where the main part of the "image" is placed in that depth - it can move front or back.

I'm not going to use the word "illusion" again - as such, I may be giving it a negative connotation. It is NOT an illusion, but perfectly REAL to me when I am attempting to enjoying MUSIC on MY system.

Charles

 

[tony ky ma]

I am talking about 180 degree phase reversal on BOTH channels - not one channel out of phase with the other. To my ears, the result has to do with the degree of the "illusion of (amount of) depth" and where the main part of the "image" is placed in that depth - it can move front or back.

I'm not going to use the word "illusion" again - as such, I may be giving it a negative connotation. It is NOT an illusion, but perfectly REAL to me when I am attempting to enjoying MUSIC on MY system.

Charles

Hi Charles
If both channels are the same, I think it is OK, because by my experience, the image of sound stage can move front and back control by the volume control
tony ma

 

[Listens2tubes]

So Charles did your rewire the head or is the issue elsewhere in the chain?

 

[stellavox]

I replaced the stock head and "wired it out"

 

[astrotoy]

I find that absolute polarity, which I think Charles is talking about, is something I can hear most of the time. I understand that many people cannot hear any difference. What I think makes a difference is often the speakers one uses. Often speakers have different drivers wired out of phase with each other (by design) so that it is difficult to hear absolute phase. Also many multimiked recordings will have different mikes out of phase with each other.

I have an absolute polarity switch on my preamp (Herron 3A) where I can flip polarity remotely from my listening chair. I also have absolute polarity switches on my TT (custom wired) and on my Pacific Microsonics Model Two for ripping and playing back digital files.

I have found that most vinyl is recorded with reversed absolute phase (in particularly British Decca and EMI classical records). Not sure about prerecorded tapes. I asked Paul Stubblebine about the Tape Project tapes and he said that he checks to make sure that the absolute phase is correct in their releases.

Larry

 

[flez007]

It is a very clear thing for me listening to voices, out of phase reproduction (Tape included) makes voices (female preferably) sound like if the artist is swallowing in air while singing.

 

[stellavox]

Thanks Guys,

I think you understand what I am saying. Ask our Boston buddy Clarke Johnson about absolute phase and he'll go off for an hour. In any case, I can hear quite a difference with the Quads - depending on the source material. What's "right" may be in the ear of the beholder.

I'd opine that in a dubbing situation, all we can hope to do is preserve whatever phase the original has. Was it "right"???

Charles

 

[rockitman]

Hi Charlie,

Can I assume that our King/Cello's and Technics 1500 (nortronics heads) wired out are in correct phase ?

 

[stellavox]

Yes Christian

 

[rockitman]

Thank you Charles. To my ear, things sound right. Just getting a little paranoid over this discussion.