the schematic is designed by my friend Locky_Z.he ask me to post here....
this is his post of the Hifidiy.net
http://www.hifidiy.net/dispbbs.asp?boardID=2&ID=21315&skin=0
it is current output amp.the output current IL=Vin * Rc / (Rsc * R6)
any comment?
this is his post of the Hifidiy.net
http://www.hifidiy.net/dispbbs.asp?boardID=2&ID=21315&skin=0
it is current output amp.the output current IL=Vin * Rc / (Rsc * R6)
any comment?
An externally hosted image should be here but it was not working when we last tested it.
A friend of mine proposes similiar idea some time ago. The idea is to make an output stage that never turn off. Output stage is a current mirror+amplification with RC/RSC. And the current passing RC never turns off, it is the bias of the opamp at minimal point. So the current to the output RSC will also never turn off.
What is the value of R6 in the formula? Is it 470ohm?
Re: Re: new idea for power amp
The OP amp work as a unity gain follower and the output signal is obtained at the power supply pins , because the output of the OP Amp is loaded with a low value resistor.
The current trough the power pins will be equal to the current in the output resistor, more the currents of the others internal stages of the OP amp.
As the amp is not closed in a overall feedback loop, this kind of OP amp driver , will introduce many nonlinearitys.
peranders said:
The OP amp work as a unity gain follower and the output signal is obtained at the power supply pins , because the output of the OP Amp is loaded with a low value resistor.
The current trough the power pins will be equal to the current in the output resistor, more the currents of the others internal stages of the OP amp.
As the amp is not closed in a overall feedback loop, this kind of OP amp driver , will introduce many nonlinearitys.
I must have been 
peranders said:I must have beenyesterday
Maybe you are today.
Can someone tell me which of the posted circuit is so surprising?
Output stages driven from opamp rails is 20 years old, especially MOSFET output stages.
Only difference i see is omiting the feedback, which does not look like a smart thing to me.
I once build an amp using OP-amp this way.
The output was taken from collectors of output transistors.
Global Feedback back to OP-input,
was taken from a small resistor between load and ground.
The relationship between this resistor and load impedance set the gain.
You can call it current feedback, as same current in load as in small resistor.
I got problems with stability.
...................
Hi-Fi = High Fidelity, is to minimize all distortions.
Because distortion tells result is not like input.
And fidel = be true to
High-End is not always the same.
Because an amp is high-end it does not have to be Hi-Fi.
A low cost amp can be more Hi-Fi.
And because you amp is 0.001% distortion of all sorts distortion
you can not be sure listening to Hi-Fi.
Yes, you can be listening to Hi-Fi,
if BOTH amps and loudspeakers are very low distortion of all sorts.
We have to not confuse amplifier fidelity with total sound system fidelity.
Many people is not mainly in search for Ultra High Fidelity.
Some are - but not everybody.
Tube amplifiers, and other, shows us,
amplifiers does not have to be ultra Hi-Fi to sound good.
But to call them Hi-Fi amplifiers would not be correct.
One thing is however true:
You can not let total sound system distortion levels be TOO HIGH,
because at some point, it will NOT sound good.
===================================
As I said in my first post,
this circuit will have distortion in the magnitude of some tube amplifiers.
My guess is 0.5-2% at normal level.
Question is what this distortion will do to sound.
Can it sound good?
I wonder if this 'new idea' amp is stable?
And if not, how can it be stabilized.
The output was taken from collectors of output transistors.
Global Feedback back to OP-input,
was taken from a small resistor between load and ground.
The relationship between this resistor and load impedance set the gain.
You can call it current feedback, as same current in load as in small resistor.
I got problems with stability.
...................
Hi-Fi = High Fidelity, is to minimize all distortions.
Because distortion tells result is not like input.
And fidel = be true to
High-End is not always the same.
Because an amp is high-end it does not have to be Hi-Fi.
A low cost amp can be more Hi-Fi.
And because you amp is 0.001% distortion of all sorts distortion
you can not be sure listening to Hi-Fi.
Yes, you can be listening to Hi-Fi,
if BOTH amps and loudspeakers are very low distortion of all sorts.
We have to not confuse amplifier fidelity with total sound system fidelity.
Many people is not mainly in search for Ultra High Fidelity.
Some are - but not everybody.
Tube amplifiers, and other, shows us,
amplifiers does not have to be ultra Hi-Fi to sound good.
But to call them Hi-Fi amplifiers would not be correct.
One thing is however true:
You can not let total sound system distortion levels be TOO HIGH,
because at some point, it will NOT sound good.
===================================
As I said in my first post,
this circuit will have distortion in the magnitude of some tube amplifiers.
My guess is 0.5-2% at normal level.
Question is what this distortion will do to sound.
Can it sound good?
I wonder if this 'new idea' amp is stable?
And if not, how can it be stabilized.
davidsrsb said:
the type of this amp is not my taste
my friend Locky_z did not build the amp in practice....
I re-designed a pre amp circuit which original designed by my another friend CWW11.its hardcore is super-pair stage.he did not view the Diyaudio and did not know the super-piar topol,but he re-invented the wheel
I name the circuit: Non-NFB DC pre amp of Dual Converter. I had simulated,build and adjust for 4 months....because my design is for the Hifidiy.net which is DIYer-groups and the Hifidiy.net will sell the pre amp kits,I don't know that I post the detail of it on here will broke the rule of Diyaduio forum or not.
can I post here?
this is the test amp which my buddy build:
An externally hosted image should be here but it was not working when we last tested it.
I continue to modify it two weeks ago:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.