Do transformers invert phase

[mr ed]

I have 2p29l pre that has a TVC output.
As I understand things each stage of amplification inverts phase .
Does the transformer invert ?

 

[disco]

It can but not necessarily. Show us a circuit to answer this question.

 

[disco]

follow the colours

 

[mr ed]

Here is the circuit.

 

[rayma]

You can hook up each of the audio transformer windings either way.
Whether the signal polarity is inverted depends on how it is connected.

If you want that circuit to preserve absolute polarity, since the tube inverts,
you would reverse one of the transformer windings so that it inverts also.
The capacitor following the transformer may not be necessary.

 

[nigelwright7557]

If it does just swap polarity of one side of the transformer.

 

[mr ed]

Well,
I simply inverted the speaker connections at the power amp it sound correct now.
I did some system changes and things did not seem right, but I have to admit my brain does not recognise out of phase as quickly as other folks I know.
Thanks for all the responses.

 

[nigelwright7557]

With a mono channel the human ear is unlikely to detect out of phase.
Out of phase usually becomes a problem with stereo where the channels are out of phase.
The bass part of the sound cancels out when the speakers are out of phase.
If the sound has poor bass in stereo then its likely one channel is wrong.

 

[EmRR]

Don't know what TVC is.

Usually treble is better one orientation versus the other due to where the capacitive effects are largest in the winding. The wrong way can sometimes cause severe treble roll-off. I would measure or listen to both 'correct phase' orientations.

 

[disco]

With a mono channel the human ear is unlikely to detect out of phase. Out of phase usually becomes a problem with stereo where the channels are out of phase. The bass part of the sound cancels out when the speakers are out of phase. If the sound has poor bass in stereo then its likely one channel is wrong.

You're saying what I was thinking: phase is relative to something, but that's the electrical way to look at the phenomenon. Human hearing works with phase to locate direction and distance, the brain filters out some audible program at request. Some of us have an absolute hearing, detecting phase foolproof.


EMRR: Transformer Volume Control, most of the time a single winding with 24 (or so) taps.

 

[abraxalito]

If the TVC is actually an auto-former - which is a single winding tapped inductor in reality then it can't invert.

 

[disco]

True, but are all TVR autoformers? Mine is anyway

 

[Tjj226]

True, but are all TVR autoformers? Mine is anyway

Nope. Several people do make true transformer volume controls. The real question is which one sounds better, a tvc or an avc.

 

[Kay Pirinha]

May someone inform me, please, what the acronym TVC stands for? Thank you!
Best regards!

 

[6A3sUMMER]

Kay Pirinha,

I believe TVA is a Transformer Volume Control.

When is a Three Letter Acronym not a Three Letter Acronym?

Example: FLA, which is a Four Letter Acronym, a Five Letter Acronym, a Forty Letter Acronym, or a Fifty Letter Acronym.

AMA an Acronym that can be taken as the American Medical Association, or the American Management Association.

NBA refers to both the National Basketball Association and to the National Benevolent Association.
The National Benevolent Association existed decades before the Basketball version.

You can see that I am not a real fan of Acronyms.

 

[lcsaszar]

IMHO acronyms are a PITA

TIA

 

[awkwardbydesign]

TVC is transformer volume control.
AVC is autoformer volume control.
I use a TVC on the output of my DHT pre instead of a potentiometer on the input, because it attenuates the hum and noise in the pre as well as the input signal.

 

[6vheater]

Next silly idea?

Best way to attenuate hum and noise is not to have any!

 

[Osvaldo de Banfield]

The schematics at post #3 lacks grid leak resistors of the cathode follower, it will not perform properly.

 

[Lightning Phil]

Nope, but whomever wires it can.