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    VTA ST-120 phase?

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    jfine

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    Re: VTA ST-120 phase?

    Post by jfine on Thu Jun 22, 2017 9:01 pm

    deepee99 wrote:Speakers don't know + from - or red from black, per se. It's that they're firing in phase that counts. Whether that's both red wires to both black connectors and both black wires to both red posts, it does not matter. The point is that they're supposed to be firing in the same direction at the same time.

    It is not a phasing issue, it is absolute polarity, they both matter, at least to me. There's really no proof either way, but to say absolute polarity does not matter, IMO, is just an opinion.

    If you can't hear the difference between a .01 Jupiter beeswax cap used as a bypass on a first order crossover for a tweeter circuit, and I can, does it mean it does not matter?

    .
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    Kentley

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    Re: VTA ST-120 phase?

    Post by Kentley on Thu Jun 22, 2017 9:44 pm

    Rich -- "Hello Peter,
    I read that two of the three drivers tubes are phase inverters."

    No one addressed this. They are phase inverters for the push/pull output tube circuitry. Each output tube (or pair in the M-125) works on half the signal at a time, thereby drastically increasing the output power. Pardon my layman's explanation. Wink
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    Kentley

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    Re: VTA ST-120 phase?

    Post by Kentley on Thu Jun 22, 2017 10:02 pm

    jfine -- the term "absolute polarity" is perhaps a more accurate one. What this means, to those scratching their heads, is that the original signal is preserved throughout the long chain of recording and reproduction as always "pushing" - positive wave, and "pulling" - negative wave. I have somewhere a test CD which presents a true and reversed "absolute polarity" sample side by side. The accompanying texts indicate that some people's brains can actually discriminate them. My, otherwise superb, brain affraid cannot.
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    Tubes4ever

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    Re: VTA ST-120 phase?

    Post by Tubes4ever on Fri Jun 23, 2017 2:13 am

    Bob Latino wrote:I am with jfine on this one. In one system that I have downstairs I have a BAT VK30SE preamp. On the remote with this preamp there is a phase button. You can alternate the phase of the preamp by just pressing the button. On the preamp itself an led comes on when the amp is in positive phase. Running two M-125's on this system (which do have positive phase), the positive phase on the preamp does give a little more bass and a more natural overall sound. You can hear the subtle difference between the positive and negative phase as you alternate presses of the phase button.

    Bob

    Bob,

    Could the difference in sound be caused by the fact that the signal passes through a different electronic path? Just wondering. It seems you would need an active component to flip the phase.
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    Peter W.

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    Re: VTA ST-120 phase?

    Post by Peter W. on Fri Jun 23, 2017 7:21 am

    jfine wrote:
    Peter W. wrote:Expectations would cover that. Not to be snarky, "google" basic physics.....

    Not sure what you mean by expectations.

    How about this,

    Instead of stating as fact, "As long as each speaker is hooked up in the same way, it makes no difference."

    just add to the end

    "...on my system, with my ears, in my room"

    Since we all experience differently, it's impossible that what you state is true.

    If you expect something to sound different, you will be subject to confirmation bias. Under such conditions, that bias will supply the necessary differences.

    That is what I mean by 'expectations'.

    OK – let us break this down into small steps for clarity:
    • Consider the sine wave – ‘sound’ in its most basic form without any overtones.
    • Let us set it, arbitrarily at 440 HZ (Standard pitch).
    • Look at the form on a scope – a nice rounded wave to equal peaks and valleys going across “Zero” in a simple pattern.
    • Let us agree for discussion purposes, and when the speakers are connected + to + and – to – , that when the peak is ‘above’ 0, the electrical impulse created by it pushes the speaker cone out.
    • Conversely, when the peak drops below 0, the impulse pulls the speaker cone in.

    So far, so good.

    Now, connect the speakers + to –  and – to +. (Both of them, mind you!)
    Now, the sine wave above the line (0), will pull the speaker cone in, below the line, push it out.
    BUT – and here is where physics comes in – the speakers are still operating at 440 HZ, and the sound coming out of them will be indistinguishable from the previous option.
    Point being that the speakers don’t care how they are hooked up, as long as they are hooked up ‘the same’ between them. They respond to the electrical impulses based on simple physics without any fuss or worry about its ‘flavor’.

    Do NOT try this at home without understanding that a pure sine wave driven into a speaker at any volume for any significant period of time could damage the voice coil, possibly fatally. *ALL* the output energy is at that single frequency into a single driver.


    Last edited by Peter W. on Fri Jun 23, 2017 7:48 am; edited 1 time in total
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    Kentley

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    Re: VTA ST-120 phase?

    Post by Kentley on Fri Jun 23, 2017 8:36 am

    You, Dogstar, seem incapable of being snarky, puppy.
    https://www.youtube.com/watch?v=eqY3FaZmh-Y

    It's only the willing who are blinded by science.

    https://www.youtube.com/watch?v=Y2VNxmn0lNA
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    Bob Latino
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    Re: VTA ST-120 phase?

    Post by Bob Latino on Fri Jun 23, 2017 8:52 am

    Tubes4ever wrote:
    Bob,

    Could the difference in sound be caused by the fact that the signal passes through a different electronic path?  Just wondering.  It seems you would need an active component to flip the phase.

    That could be true but I don't believe that is the major factor. What happens when you try to tell the difference regarding which phase sounds best or if there is any perceptible difference is the time it takes to swap the speaker cables + and -. You auditory memory is short and by the time you make the cable switch, you have lost most of the memory of what the first sound was like. With the phase switch on the remote on my BAT preamp, I can instantly compare the two phases and when you do that there is a subtle difference in the sound. I think that the difference is this > With a positive phase the leading edge of a transient sound is OUT into the room towards you. A cymbal sounds a little more real when the phase of your system pumps the leading edge of the transient towards you.

    Bob
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    Kentley

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    Re: VTA ST-120 phase?

    Post by Kentley on Fri Jun 23, 2017 8:59 am

    "With a positive phase the leading edge of a transient sound is OUT into the room towards you. A cymbal sounds a little more real when the phase of your system pumps the leading edge of the transient towards you." -- Bob L.

    That is likely the definitive statement in this debate. Bravo! cheers
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    jfine

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    Re: VTA ST-120 phase?

    Post by jfine on Fri Jun 23, 2017 12:15 pm

    Peter W. wrote:

    If you expect something to sound different, you will be subject to confirmation bias. Under such conditions, that bias will supply the necessary differences.

    That only applies to those who suffer from such conditions, and since the sound I hear is so much different when I swap the leads, it cannot possibly apply, to me.

    My wife, whom I usually leave out of all the A/B tests, confirms there is a difference, and so does my daughter, both of whom do not know what positive and negative means.




    OK – let us break this down into small steps for clarity:
    • Consider the sine wave – ‘sound’ in its most basic form without any overtones.
    • Let us set it, arbitrarily at 440 HZ (Standard pitch).
    • Look at the form on a scope – a nice rounded wave to equal peaks and valleys going across “Zero” in a simple pattern.
    • Let us agree for discussion purposes, and when the speakers are connected + to + and – to – , that when the peak is ‘above’ 0, the electrical impulse created by it pushes the speaker cone out.
    • Conversely, when the peak drops below 0, the impulse pulls the speaker cone in.

    So far, so good.

    Now, connect the speakers + to –  and – to +. (Both of them, mind you!)
    Now, the sine wave above the line (0), will pull the speaker cone in, below the line, push it out.
    BUT – and here is where physics comes in – the speakers are still operating at 440 HZ, and the sound coming out of them will be indistinguishable from the previous option.
    Point being that the speakers don’t care how they are hooked up, as long as they are hooked up ‘the same’ between them. They respond to the electrical impulses based on simple physics without any fuss or worry about its ‘flavor’.

    Do NOT try this at home without understanding that a pure sine wave driven into a speaker at any volume for any significant period of time could damage the voice coil, possibly fatally. *ALL* the output energy is at that single frequency into a single driver.

    I understand you're trying to prove it's not true with measurements, using the tools you have at your disposal.

    There are things that cannot be measured by us, either because we do not have the correct tools, or we simply do not have all the information needed to understand the problem. The tools you are using are not equal to a human ear and the individual perceptions that go along with it.

    Since there are many others "out there" on the net that "hear" this difference, it would therefore be illogical to conclude that "and the sound coming out of them will be indistinguishable from the previous option".
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    jfine

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    Re: VTA ST-120 phase?

    Post by jfine on Fri Jun 23, 2017 12:21 pm

    An interesting read, although I don't think I agree with all of it,

    absolutepolarity.com
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    deepee99

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    Re: VTA ST-120 phase?

    Post by deepee99 on Fri Jun 23, 2017 12:23 pm

    Gibberish.
    If one speaker sucks while the other blows, the net air displacement is nil. Sound is transmitted by air. It's really quite that simple.
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    jfine

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    Re: VTA ST-120 phase?

    Post by jfine on Fri Jun 23, 2017 12:31 pm

    Bob Latino wrote:

    That could be true but I don't believe that is the major factor. What happens when you try to tell the difference regarding which phase sounds best or if there is any perceptible difference is the time it takes to swap the speaker cables + and -. You auditory memory is short and by the time you make the cable switch, you have lost most of the memory of what the first sound was like. With the phase switch on the remote on my BAT preamp, I can instantly compare the two phases and when you do that there is a subtle difference in the sound. I think that the difference is this > With a positive phase the leading edge of a transient sound is OUT into the room towards you. A cymbal sounds a little more real when the phase of your system pumps the leading edge of the transient towards you.

    Bob

    It is the transient sound that is different, also for me, the bass is stronger, the hi-hats do not sound smashed, and ditto with multiple vocals, the imaging is also much better, I dunno guys, it's night and day here, trying to confirm it with science seems like an assault on my credibility. It is there, and whoever would like to stop by is more than welcome anytime, in the Portland OR area, K?
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    Bob Latino
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    Re: VTA ST-120 phase?

    Post by Bob Latino on Fri Jun 23, 2017 12:59 pm

    There will always be disagreement about speaker phase and whether it is audible. Interestingly enough, I have a phase switch on the sub-woofer on my home theater system that seems to integrate with the other speakers better when I have the switch in the 180 degree (reverse phase) position ?

    Bob
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    Bob Latino
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    Re: VTA ST-120 phase?

    Post by Bob Latino on Sat Jun 24, 2017 8:28 am

    I am going to put a cap on this thread because of flip answers, thread "drift" and posters jumping on each other instead of stating their opinion. The warning is > you can give your opinion as long as you don't attack or attempt to belittle another poster while doing so ..

    Bob

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