Yes I've seen the Vdiffs, I agree they are there, we all know this mechanism. But what is your point? Do you have a point or are you just having fun?
jd
I'm sorry, I see a lot of graphs, I have no idea what they signify. It may well be that your amplifier is different than others, and that you solved some problem in a certain way, but I have no idea what it is, I can't handle the language.
Maybe you should try to address one specific item and discuss this instead of referring to your website with a lot of stuff that only confuses.
jd
And we have no phase shift in the speakers crossover filters? hehe.. This thread is so amazingly strange..
I don't mind non practical discussions, but this is too much..
One has got to see the big picture. NO amplifier could EVER give me the upgrade I made when building my new loudspeakers,compared to the old ones..
And in fact ,I use jx92s elements and could have been built with no phase shift, and yet I did build in a crossover filter ;-) ..
I don't mind non practical discussions, but this is too much..
One has got to see the big picture. NO amplifier could EVER give me the upgrade I made when building my new loudspeakers,compared to the old ones..
And in fact ,I use jx92s elements and could have been built with no phase shift, and yet I did build in a crossover filter ;-) ..
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LOL, well Federmann claims 40 years of experience...
http://www.diyaudio.com/forums/solid-state/154104-topology-federmann-hqqf-55-a.html#post1964100
Cheers
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I still think few people here really understand what he's saying. Sure, there is a language barrier but that excuse breaks down... What he's saying is not entirely clear but it's perfectly clear what he's NOT saying.
He never said that phase shift was a distortion
I think Curl may be right about FM distortion. Try Doppler affect, except with electrons. This would be caused by nonlinear reverse diode capacitance, typically at the VAS C-B junction. As voltage increases here, capacitance decreases, and the energy stored in it has to go somewhere... This causes nonlinear phase shifts that are modulated by output voltage, which causes doppler-type affect on any subtler, HF waveforms (thinking about it, this must play hell with the "harmonic distribution" of trumpets, strings...).
Am I close?
- keantoken
He never said that phase shift was a distortion
I think Curl may be right about FM distortion. Try Doppler affect, except with electrons. This would be caused by nonlinear reverse diode capacitance, typically at the VAS C-B junction. As voltage increases here, capacitance decreases, and the energy stored in it has to go somewhere... This causes nonlinear phase shifts that are modulated by output voltage, which causes doppler-type affect on any subtler, HF waveforms (thinking about it, this must play hell with the "harmonic distribution" of trumpets, strings...).
Am I close?
- keantoken
Excellent. So could you kindly show measured (not simulated) 100kHz sine response at full power, and 20kHz square response at half power? Load 4 ohm, and 4ohm with some capacitance in parallel. Measured on your amplifier that fulfills your Vdiff criteria. This would be a good starting point to assess a real quality of your amplifier.
As a starter, I have prepared 20kHz square measurement into 4ohm load, of the PA2 power amplifier
Attachments
OK, are you saying that distortion creates higher harmonics, that can go up to 100kHz, and that it is these harmonics that you can hear? Is that the issue?
jd
Don't know if you're close. I'm trying to get to what his issue is. Once we know that, then we can discuss it. I haven't seen Federmann address anything of what you speculate on in your post. This is Federmann's thread so I think we should try to understand him before going off on the tangent of our personal hobbyhorse.
jd
This thread is becoming so difficult to keep up with.
How have we got from a LM741 at the start to this ?
I too would like to see some "real world" measurements and scope shots as these say far more than any words or simulations ever can.
Some are talking now of audible effects at HF. While there is work to support the theory, I can't see the "real world" relevance of that in a typical audio reproduction system at home.
What source material have you, that has all frequencies out to even 50k recorded ?
What speakers have you that reproduce that ?
I suspect you get more "change" in sound at home by moving your listening position by a few centimeters or drawing the curtains etc.
This thread is becoming difficult to keep up with.
So can we see some scope shots please along the lines of these which show a prototype HEXFET amp at 20 volts into 5 ohm at 20khz, and then with the 5 ohm replaced with a 2.2uf metalised polyester cap... you could draw an arc connecting and removing that
Let's stop going round in circles please... scope shots are worth a thousand words IMO
Your amp may have some merit... please let us see real performance measurements of it.
How have we got from a LM741 at the start to this ?
I too would like to see some "real world" measurements and scope shots as these say far more than any words or simulations ever can.
Some are talking now of audible effects at HF. While there is work to support the theory, I can't see the "real world" relevance of that in a typical audio reproduction system at home.
What source material have you, that has all frequencies out to even 50k recorded ?
What speakers have you that reproduce that ?
I suspect you get more "change" in sound at home by moving your listening position by a few centimeters or drawing the curtains etc.
This thread is becoming difficult to keep up with.
So can we see some scope shots please along the lines of these which show a prototype HEXFET amp at 20 volts into 5 ohm at 20khz, and then with the 5 ohm replaced with a 2.2uf metalised polyester cap... you could draw an arc connecting and removing that
Let's stop going round in circles please... scope shots are worth a thousand words IMO
Your amp may have some merit... please let us see real performance measurements of it.
Attachments
I wasn't suggesting that, sorry if I gave the impression. But it's so easy to replace what one doesn't understand with personal ideas. JC always sees FM and PIM no matter what the thread is about. I am especially interested in feedback. To be fair to the OP, lets see what he is on about.
Do we agree that his issue is hf distortion components, and that he has a way to eliminate or decrease that?
Pavel, you speak the language. What IS this all about, really?
jd
Jan, even in our mother tongue, Czech language, the degree of confusion is the same as in English.
Please don't want for me to say what I really mean about it. I did it once and was binned for a week, see :
http://www.diyaudio.com/forums/everything-else/5121-sin-bin-18.html#post1994172
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