Wood Effect?
Changing the Absolute Phase of your music playback system is really easy.
Turn your power amplifier off.
Reverse the Red and Black of Both left channel And right channel loudspeaker wires at the amplifier output.
Turn your power amplifier on.
Now, listen to your favorite recordings.
Have Fun!
Your music playback system . . . Either sounds the Same, Or sounds Better, Or sounds Worse.
Only you can decide about the results (after all, these are your favorite recordings, on your system, in your room).
Your Mileage May Vary from other's Mileage.
Just my opinions
Changing the Absolute Phase of your music playback system is really easy.
Turn your power amplifier off.
Reverse the Red and Black of Both left channel And right channel loudspeaker wires at the amplifier output.
Turn your power amplifier on.
Now, listen to your favorite recordings.
Have Fun!
Your music playback system . . . Either sounds the Same, Or sounds Better, Or sounds Worse.
Only you can decide about the results (after all, these are your favorite recordings, on your system, in your room).
Your Mileage May Vary from other's Mileage.
Just my opinions
It’s not that easy. Not every transformer you can put out of phase without a change of performance. Please measure your own transformers to check out for a start.
Also on this site you can see some measurements that it’s not always what you think that will happen:
http://triodedick.com/.
Look for “mededelingen”
Also on this site you can see some measurements that it’s not always what you think that will happen:
http://triodedick.com/.
Look for “mededelingen”
@tubes4all:
In your link it is about the risk of switching the primary connections because the manufacturer was not very clear with proper indication.
Switching phase at the loudspeaker terminals will not do so much harm.
In your link it is about the risk of switching the primary connections because the manufacturer was not very clear with proper indication.
Switching phase at the loudspeaker terminals will not do so much harm.
Tubes4all,
Take an amplifier with a Black Banana Common output, and a Red Banana 8 Ohm output.
1. Connect the loudspeaker cable at the amplifier output, as per normal convention: Black Banana out to Black Banana; Red Banana out to Red Banana.
2. Connect the loudspeaker cable at the amplifier output, opposite to normal convention: Black Banana out to Red Banana; Red Banana out to Black Banana.
(Do that for Both channels, or you Will notice a change, the bass will go away, and the sound will be coming from beyond the speakers, with no center sound).
If you do not have Banana connectors, use whatever ones your system has.
1. Connect normally
2. Connect with the cable leads reversed
No soldering needed.
No Output transformer primary or secondary re-wiring of the amplifier.
I am not talking about reconnecting the primary inside of the amplifier, and I am not talking about reconnecting the secondary inside of the amplifier.
Just as I said, Simple and Easy.
Take an amplifier with a Black Banana Common output, and a Red Banana 8 Ohm output.
1. Connect the loudspeaker cable at the amplifier output, as per normal convention: Black Banana out to Black Banana; Red Banana out to Red Banana.
2. Connect the loudspeaker cable at the amplifier output, opposite to normal convention: Black Banana out to Red Banana; Red Banana out to Black Banana.
(Do that for Both channels, or you Will notice a change, the bass will go away, and the sound will be coming from beyond the speakers, with no center sound).
If you do not have Banana connectors, use whatever ones your system has.
1. Connect normally
2. Connect with the cable leads reversed
No soldering needed.
No Output transformer primary or secondary re-wiring of the amplifier.
I am not talking about reconnecting the primary inside of the amplifier, and I am not talking about reconnecting the secondary inside of the amplifier.
Just as I said, Simple and Easy.
That's not a triode. We are talking about zero feedback triodes. Someone would argue that a triode can been seen as a pentode with internal (auto)feedback but there is no control on it so it is what is. There are general rules to establish if something is HiFi or not, regardless of the device.
I use pentodes with cathode feedback and they become very linear "triodes" but the more feedback I use and more the 0V bias curve moves towards zero anode voltage, hence less possibility and/or less usefulness of class A2 operation. Pentodes with cathode feedback already have high efficiency in Class A1. More than real triodes for sure.
For the rest everyone feathers his own nest. There is no absolute solution and I prefer BOTH triodes and pentodes!
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Diy is not HiFi. We all know that the power rating of amplifiers is not the major factor to consider. I was just sharing that with a very complex setup it is possible to obtain in 300B SET more power, and the circuit to accomplish that wasn't a compromise which would sacrifice the sound under 6 watts. There are EL34 PP designs for 25, 50, 75 watts, and they can all equally good. In my current system, with 6 different amplifiers available, I get the most enjoyment with at least 20 clean watts of power under 0.1% THD. With my system I would favor building the highest power possible 300B, but instead I would probably built a parallel el34 SET.
Then do what you like but what you say is just your (very questionable) opinion The amplifier is the LEAST of the problems for true HiFi. To me, you look more like a vendor.
Ofcourse it dosn’t do much harm, no feedback, but the response will chance*. It wil also change less then switching primary windings.
* depending on how the transformer is made, most transformers are not 100% symetric.
I expect that most readers of this thread have done both of these things at least once:
1. Connected Both loudspeakers with amplifier + to loudspeaker -, and amplifier - (common) to loudspeaker +.
2. Connected One loudspeaker "correctly", and the Other loudspeaker as # 1. above (the bass goes away, and the sound appears to come from beyond the outside of the Left and Right speakers, with no sound in the center)
If you have never made mistakes like that . . . congratulations, you are perfect.
And, if an amplifier was ever harmed by # 1. or # 2. above, please report that to us.
1. Connected Both loudspeakers with amplifier + to loudspeaker -, and amplifier - (common) to loudspeaker +.
2. Connected One loudspeaker "correctly", and the Other loudspeaker as # 1. above (the bass goes away, and the sound appears to come from beyond the outside of the Left and Right speakers, with no sound in the center)
If you have never made mistakes like that . . . congratulations, you are perfect.
And, if an amplifier was ever harmed by # 1. or # 2. above, please report that to us.
Some people will laugh about this other people are smarter and think what will happen if my transformer has a limited frequency response, for instance a fiat transformer?
If you are an old man you can laugh about those minor things but, if you have better ears that might be the difference in good enough sound or to harsh sound.
Btw, if you take your hobby/system not serieus you never get good sound
If you are an old man you can laugh about those minor things but, if you have better ears that might be the difference in good enough sound or to harsh sound.
Btw, if you take your hobby/system not serieus you never get good sound
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tubes4all,
If your amplifier sounds harsher with the loudspeaker cable reversed, versus with the loudspeaker connected non-reversed, then . . .
1. You need to fix the amplifier, speakers, or both.
2. You might be experiencing the "Wood Effect".
3. You might need to have your ears checked, perhaps they are oversensitive to the difference of the normal trombone waveform which always starts with a rising transient (air compression),
versus a trombone recording with a total recording/playback chain that has reversal of absolute phase:
The sound starts with a falling transient (air rarefaction).
"Wood Effect" Et Al.
The above are all ageless things.
You can not be old and a minor at the same time.
Laugh all you want!
I enjoy the sound of most of my amplifier designs/builds.
Those amplifiers of mine that do not sound good no longer exist, they have been completely re-designed/re-built into something that sounds good.
Enjoy the Music!
If your amplifier sounds harsher with the loudspeaker cable reversed, versus with the loudspeaker connected non-reversed, then . . .
1. You need to fix the amplifier, speakers, or both.
2. You might be experiencing the "Wood Effect".
3. You might need to have your ears checked, perhaps they are oversensitive to the difference of the normal trombone waveform which always starts with a rising transient (air compression),
versus a trombone recording with a total recording/playback chain that has reversal of absolute phase:
The sound starts with a falling transient (air rarefaction).
"Wood Effect" Et Al.
The above are all ageless things.
You can not be old and a minor at the same time.
Laugh all you want!
I enjoy the sound of most of my amplifier designs/builds.
Those amplifiers of mine that do not sound good no longer exist, they have been completely re-designed/re-built into something that sounds good.
Enjoy the Music!
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tubes4all,
I never said the 'Wood Effect' is real.
I never said the 'Wood Effect' is not real.
Do not accuse me of making that decision for anybody.
Please do not accuse me of deciding that for you.
I leave the decision up to you.
In regards to switching the secondary to loudspeaker connections . . .
You are the one who mentioned Harsh first.
I merely commented using your own words.
I am glad that your transformers are very good.
Who uses Fiat transformers?
I never heard of them until you mentioned them. They must not work well (in the USA), so I do not purchase any Fiat transformers.
I never said the 'Wood Effect' is real.
I never said the 'Wood Effect' is not real.
Do not accuse me of making that decision for anybody.
Please do not accuse me of deciding that for you.
I leave the decision up to you.
In regards to switching the secondary to loudspeaker connections . . .
You are the one who mentioned Harsh first.
I merely commented using your own words.
I am glad that your transformers are very good.
Who uses Fiat transformers?
I never heard of them until you mentioned them. They must not work well (in the USA), so I do not purchase any Fiat transformers.
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I say there is a difference between the connections you use at the secondair windings.
And i said it might be … etc etc.
But you should measure your transformer instead of telling stories of “Wood effect” without any physics behind it.
Waltubes is telling a lot of lies here and you are not far away of this.
And i said it might be … etc etc.
But you should measure your transformer instead of telling stories of “Wood effect” without any physics behind it.
Waltubes is telling a lot of lies here and you are not far away of this.
zintolo,
I said:
"Damping Factor:
How many of you:
1. Have ever measured the inductance of the output transformer secondary?
Note: The output transformer secondary inductance affects the low frequency damping factor, and it affects the LCR resonances of the woofer (open baffle, ported baffle, closed baffle, horn, etc.)".
You said:
"Can I ask you an help with this OPT as example?"
https://sklep.toroidy.pl/en_US/p/TTG-KT88SE-Tube-output-UL-transformer-3kOhm-KT88-300B-SE/566
Primary Inductance Lp = 39,5 H
Total Primary DC Resistance = 109,7 Ω
Total Secondary DC Resistance = 0,7 Ω
Effective Primary Capacitance = 7,6 nF
Turns Ratio (Np:Ns) = 27,39:1 (4Ω) , 19,36:1 (8Ω)
Inductance Ratio is the same as the Square of the Turns Ratio.
Turns 27.39:1 27.39 Squared = 750
39.5H primary / 750 = 0.0527H (52.7mH) 4 Ohm Tap
Turns 19.36:1 19.36 Squared = 375
39.5H primary / 375 = 0.105H (105mH) 8 Ohm Tap
7.6nF capacitance is only 1,047 Ohms capacitive reactance at 20kHz.
That capacitive reactance is only 1/3 of the primary impedance of 3k Ohm.
Expect a possible high frequency roll off (1k capacitive reactance in parallel with 3k primary).
3k + 110 Ohm DCR 20 Log (3000/3110) = -0.3dB (insertion loss)
8 Ohm + 0.7 Ohm DCR 20 Log (8/8.7) = - 0.7dB (insertion loss)
That is -0.3 dB + -0.7 dB = -1.0 dB total insertion loss from the 3k primary and 8 secondary DCRs.
Example -1 db (loss) . . . 12.5 Watts from the output tube(s) into the primary = 9.9 Watts out of the secondary.
I hope that tells you some of the hidden specifications (that the manufacturer did not directly tell you, you have to calculate based on the specifications that they do tell you).
It was very good of the manufacturer to tell you what he did tell you!
I said:
"Damping Factor:
How many of you:
1. Have ever measured the inductance of the output transformer secondary?
Note: The output transformer secondary inductance affects the low frequency damping factor, and it affects the LCR resonances of the woofer (open baffle, ported baffle, closed baffle, horn, etc.)".
You said:
"Can I ask you an help with this OPT as example?"
https://sklep.toroidy.pl/en_US/p/TTG-KT88SE-Tube-output-UL-transformer-3kOhm-KT88-300B-SE/566
Primary Inductance Lp = 39,5 H
Total Primary DC Resistance = 109,7 Ω
Total Secondary DC Resistance = 0,7 Ω
Effective Primary Capacitance = 7,6 nF
Turns Ratio (Np:Ns) = 27,39:1 (4Ω) , 19,36:1 (8Ω)
Inductance Ratio is the same as the Square of the Turns Ratio.
Turns 27.39:1 27.39 Squared = 750
39.5H primary / 750 = 0.0527H (52.7mH) 4 Ohm Tap
Turns 19.36:1 19.36 Squared = 375
39.5H primary / 375 = 0.105H (105mH) 8 Ohm Tap
7.6nF capacitance is only 1,047 Ohms capacitive reactance at 20kHz.
That capacitive reactance is only 1/3 of the primary impedance of 3k Ohm.
Expect a possible high frequency roll off (1k capacitive reactance in parallel with 3k primary).
3k + 110 Ohm DCR 20 Log (3000/3110) = -0.3dB (insertion loss)
8 Ohm + 0.7 Ohm DCR 20 Log (8/8.7) = - 0.7dB (insertion loss)
That is -0.3 dB + -0.7 dB = -1.0 dB total insertion loss from the 3k primary and 8 secondary DCRs.
Example -1 db (loss) . . . 12.5 Watts from the output tube(s) into the primary = 9.9 Watts out of the secondary.
I hope that tells you some of the hidden specifications (that the manufacturer did not directly tell you, you have to calculate based on the specifications that they do tell you).
It was very good of the manufacturer to tell you what he did tell you!
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tubes4all,
For several years, I had a Rhode & Schwarz $50,000 Vector Network Analyzer and $10,000 precision calibration kit that I used at work.
It had a frequency range of 10Hz to 4 GHz.
I used it to measure Audio Output transformers and Audio Interstage transformers.
I no longer have access to that Vector Network Analyzer (VNA).
Now I make my measurements of output transformers, using my own humble test equipment.
Thanks for the vote(s) of confidence.
Do not bother with thinking about or researching the "Wood Effect".
I am sorry I caused you so much grief.
Regarding switching the loudspeaker cable leads at the amplifier output connectors . . .
1. Does not affect the global negative feedback from the secondary (if there is any global negative feedback).
2. Does not affect the cathode negative feedback from the secondary (if there is any global negative feedback).
3. Does not switch the primary connections.
4. It only affects the absolute phase (correct or incorrect); plus it seems to affect some people's minds.
Who is worried about an output transformers high frequency performance?
I might be.
My latest amplifier (no global negative feedback) is -3dB at 100kHz.
Considering the output transformer's essentially 2-pole high frequency roll off, that means the -1 dB response is at about 70kHz.
Better than most tweeters, and is better than most human ears.
Just my opinions
For several years, I had a Rhode & Schwarz $50,000 Vector Network Analyzer and $10,000 precision calibration kit that I used at work.
It had a frequency range of 10Hz to 4 GHz.
I used it to measure Audio Output transformers and Audio Interstage transformers.
I no longer have access to that Vector Network Analyzer (VNA).
Now I make my measurements of output transformers, using my own humble test equipment.
Thanks for the vote(s) of confidence.
Do not bother with thinking about or researching the "Wood Effect".
I am sorry I caused you so much grief.
Regarding switching the loudspeaker cable leads at the amplifier output connectors . . .
1. Does not affect the global negative feedback from the secondary (if there is any global negative feedback).
2. Does not affect the cathode negative feedback from the secondary (if there is any global negative feedback).
3. Does not switch the primary connections.
4. It only affects the absolute phase (correct or incorrect); plus it seems to affect some people's minds.
Who is worried about an output transformers high frequency performance?
I might be.
My latest amplifier (no global negative feedback) is -3dB at 100kHz.
Considering the output transformer's essentially 2-pole high frequency roll off, that means the -1 dB response is at about 70kHz.
Better than most tweeters, and is better than most human ears.
Just my opinions
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