Links do not open, Could I trouble you to find the schematics and post them here as Graphics (PNG) files.
MiiB (4301)
Links do not open, Could I trouble you to find the schematics and post them here as Graphics (PNG) files.
http://s006.radikal.ru/i213/1401/68/7bef8b0dd643.png
Best regards
Petr
Links do not open, Could I trouble you to find the schematics and post them here as Graphics (PNG) files.
http://s006.radikal.ru/i213/1401/68/7bef8b0dd643.png
Best regards
Petr
MiiB (4303)
Are the EC transistors connected to the Rails or to the VAS drive..??
I in my designs VAS using broken cascode
http://s019.radikal.ru/i610/1401/39/235f2cf252a7.png
best regards
Petr
Are the EC transistors connected to the Rails or to the VAS drive..??
I in my designs VAS using broken cascode
http://s019.radikal.ru/i610/1401/39/235f2cf252a7.png
best regards
Petr
I'll use it for a breadboard for mods. I did this with some older distortion analyzers (HP339A) as I didnt have to build much.. Chassis, power supply and good basic circuitry to start with. And, i need some music in the house! Unit will be in my hands tomorrow. I'm updating my own amps meanwhile.... waiting for parts. The 7025 may end up as a DIY mod or goes to Bangkok place as it has nothing there, yet.
Thx-RNMarsh
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what is the slew rate on your design? what does it sound like (characteristics) compared to VFA you have heard?
[trying to get a lot of data points of uncontrolled listening tests... to see if results are random 50/50]
-Richard
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RNMarsh
what is the slew rate on your design? what does it sound like (characteristics) compared to VFA you have heard?
[trying to get a lot of data points of uncontrolled listening tests... to see if results are random 50/50]
Slew rate depends on the supply voltage and bandwidth. Slew rate is very important for amplifiers with GNFB weak output stage, which is opposed to bad Back EMF.
The amplifier is powered with ± 40 V slew rate beeps theoretically does not exceed 0.4 V / us . When that Baxandal tried virtually determine the maximum SR of real audio signals , but more than 0.15 V / us he did not find
Amplifier without GNFB and negative output impedance does not need patching cables and acoustic elements crossovers due to the influence Back EMF. He compensates them .
The slew rate of the proposed amplifier is less than 40 V / us (bandwidth 200 kHz) , which is 100 times the stock .
As for sound quality, it has outplayed many tube , transistor and hybrid brands.
Best regards
Petr
what is the slew rate on your design? what does it sound like (characteristics) compared to VFA you have heard?
[trying to get a lot of data points of uncontrolled listening tests... to see if results are random 50/50]
Slew rate depends on the supply voltage and bandwidth. Slew rate is very important for amplifiers with GNFB weak output stage, which is opposed to bad Back EMF.
The amplifier is powered with ± 40 V slew rate beeps theoretically does not exceed 0.4 V / us . When that Baxandal tried virtually determine the maximum SR of real audio signals , but more than 0.15 V / us he did not find
Amplifier without GNFB and negative output impedance does not need patching cables and acoustic elements crossovers due to the influence Back EMF. He compensates them .
The slew rate of the proposed amplifier is less than 40 V / us (bandwidth 200 kHz) , which is 100 times the stock .
As for sound quality, it has outplayed many tube , transistor and hybrid brands.
Best regards
Petr
Nope. That would be the "rise time", a completely different animal.
Low GNFB worsens the Back EMF issues, since it increases the amplifiers' output impedance.
I still cannot see the schema's - I get a message in Russian but the rest of the page is blank - can you try to repost?
RNMarsh (4310)
Petr1951 --- I am not sure I understand --- you increased the SR to more than 100 times stock? And, this sounds better?
Other wise, I tend do agree with Waly about the explanation given.
Slew rate (SR) of real audio signals do not exceed 0.4 V / us
my amplifier have slew rate about 40 V /us, 100 times higher than the actual signal.
Many authors now argue that the SR of increase should be at least 200 V / us, and even better 500
But it is important only for amplifiers with GNFB!
Waly (4309)
Nope. That would be the "rise time", a completely different animal.
Low GNFB worsens the Back EMF issues, since it increases the amplifiers' output impedance.
my amp without any GNFB
output resistance of the follower with corrector Hawksford depends on the configuration of the bridge error correction and can be either positive, zero or negative.
I use a small negative value of the output resistance of about minus 0.2 ohms
Best regards
Petr
Petr1951 --- I am not sure I understand --- you increased the SR to more than 100 times stock? And, this sounds better?
Other wise, I tend do agree with Waly about the explanation given.
Slew rate (SR) of real audio signals do not exceed 0.4 V / us
my amplifier have slew rate about 40 V /us, 100 times higher than the actual signal.
Many authors now argue that the SR of increase should be at least 200 V / us, and even better 500
But it is important only for amplifiers with GNFB!
Waly (4309)
Nope. That would be the "rise time", a completely different animal.
Low GNFB worsens the Back EMF issues, since it increases the amplifiers' output impedance.
my amp without any GNFB
output resistance of the follower with corrector Hawksford depends on the configuration of the bridge error correction and can be either positive, zero or negative.
I use a small negative value of the output resistance of about minus 0.2 ohms
Best regards
Petr
It is possible to extract better information from repeated tests.
But a lot of worthless data points is just worthlessness multiplied.
I still remember some of the non-parametric methods from my bachelors in statistics, even if it's been a while since I moved professions.
The sine qua non is that each individual test is unbiased, which means blind, of course.
If you are actually interested in real data then I can help with the statistics.
Best wishes
David
MiiB (4314)
Don't you have feedback through the opamp network..??
Operational amplifiers are responsible for the constant component voltage of the output - the servo. They work at subsonic frequencies below 1 Hz and do not affect in sound range. In the driver, only one shoulder power of input stage is controlled integrator.
Best regards
Petr
Don't you have feedback through the opamp network..??
Operational amplifiers are responsible for the constant component voltage of the output - the servo. They work at subsonic frequencies below 1 Hz and do not affect in sound range. In the driver, only one shoulder power of input stage is controlled integrator.
Best regards
Petr
You choice, in my book this is useless and dangerous, from a stability perspective.
I know about a theoretical improvement when matching the speaker Qts/Qes, but that would be exactly valid for a particular speaker only.
Thank you... it isnt that i am completely uninformed of the testing methods. I am looking at this from another perspective to see IF there is 'potentially' something there worth further , more structured, detailed inquiry. At which time I know a PHD in statistics and also a PHD/professor of Mathematics (UCLA) whom i can ask for help or answers. If it looks like there is a pattern, he can see if it is real or not. but at a meta-data level of thousands over a long time is the present view.
A not so quick review of magazines (paper or internet) is one place to gather informal data re CFA qualities/characteristics. Another is from the internet sites which sell products and ask for reviews/ pro-con feedback. Some give listening impressions. From a few hundred of those product reviews (which i have identified as using CFA) will be a start in finding out if there is a pattern of thought about the CFA.
Thx anyway -- RNMarsh
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Waly (4318)
You choice, in my book this is useless and dangerous, from a stability perspective.
I know about a theoretical improvement when matching the speaker Qts/Qes, but that would be exactly valid for a particular speaker only.
Waly! in your book, it is useless and dangerous, and in my experience it is very useful and safe. Repeat this all very pleased with the sound of power and no one complains about the instability of work. In my country, the firm was lounging on manufacturing speakers and amplifiers. After fabrication the amplifier of my circuits the company revived again. Improvements do not depend on the speakers. Tested with different types: horn, closed, labirinth (mazes) and other acoustic design.
Best regards
Petr
You choice, in my book this is useless and dangerous, from a stability perspective.
I know about a theoretical improvement when matching the speaker Qts/Qes, but that would be exactly valid for a particular speaker only.
Waly! in your book, it is useless and dangerous, and in my experience it is very useful and safe. Repeat this all very pleased with the sound of power and no one complains about the instability of work. In my country, the firm was lounging on manufacturing speakers and amplifiers. After fabrication the amplifier of my circuits the company revived again. Improvements do not depend on the speakers. Tested with different types: horn, closed, labirinth (mazes) and other acoustic design.
Best regards
Petr