Here is a class C Hi-Fi amplifier.
It is very temperature stable, power transistors work in class C.
There is a constant current power transistor bypass to eliminate crossover distortion.
Some of the circuits is shown here. Needs an anti-saturation front end.
It is very temperature stable, power transistors work in class C.
There is a constant current power transistor bypass to eliminate crossover distortion.
Some of the circuits is shown here. Needs an anti-saturation front end.
Definitely NOT class C. See Class C power amplifier circuit diagram and theory. Output characteristics DC load line .
It is not class AB as there is no shoot through quiescent current
We will have to agree on a class name for it?
Tuning this amplifier, components shown need tuning.
1) tune the offset null components to get less than 1mV and trim of +/- 30mV.
2) decrease the degeneration resistors so the amplifier has a maximum DC regulation error of 0.25%
3) play with the phase margin compensator to get 120 degrees at 0dB gain.
We will have to agree on a class name for it?
Tuning this amplifier, components shown need tuning.
1) tune the offset null components to get less than 1mV and trim of +/- 30mV.
2) decrease the degeneration resistors so the amplifier has a maximum DC regulation error of 0.25%
3) play with the phase margin compensator to get 120 degrees at 0dB gain.
No it´s not.
It´s a tons of crossover distortion Class B amplifier.
And horrible distortion strips the Hi Fi label from it.
well, no biasing / Class B does that 😉
No they don´t:
a) it´s unbiased Class B, period.
b) for Class C you need output devices brutally saturating all the time ... fine in, say, an RF transmitter, an ultrasonic cleaner power amp, a Sonar, etc. ... but not in the Audio realm, whare output signal should be reasonably similar to input signal, the difference being called "distortion".
It does not eliminate anything, plus it does not even get to the speaker.
Those transistors are not modulated in any way by Audio signal.
You do not understand crossover distortion mechanism to begin with.
That´s the lesser of your problems.🙄
"Class B" is conduction *exactly* half the time.
This never happens in real life; it is just a theory. All real "B" amps either run in AB, or are biased hard-OFF ("C") and cause large distortion at LOW levels.
I accept the THD may read low at 6,000 Watts(!!). How does it sound at 1 Watt?
This never happens in real life; it is just a theory. All real "B" amps either run in AB, or are biased hard-OFF ("C") and cause large distortion at LOW levels.
I accept the THD may read low at 6,000 Watts(!!). How does it sound at 1 Watt?
Q10 collector is not connected. This would leave the current from Q9 running X3 in a very small range of class-A. If it was connected as intended, two constant currents sources do not substitute for the missing signal at crossover. They would just cancel each other. Why do novices always want to build huge amps?? Part of the learning curve, I guess. I suggest you start with a small (15Watt) "Sinclair" clone and then add current mirror, Darlington VAS etc.
Nope, you just need each output device to conduct less than half a cycle, assuming a sine-wave-like signal.
Why do most of the truly daft ideas in audio come from those engaged (or hoping to be engaged) in commercial audio?
This amp may (just) qualify as Class C. It certainly won't qualify as hi-fi. Any alleged low distortion in simulation probably comes from the error of leaving one CCS disconnected.
This amp may (just) qualify as Class C. It certainly won't qualify as hi-fi. Any alleged low distortion in simulation probably comes from the error of leaving one CCS disconnected.
Actually, I am a stable lad and my job is to muck out horse stables.
The improved amplifier actually turns on / off the current source / sink so only one is on at a time, 25mA from +/- 15 Volt rails.
A voltage comparator detects output voltage below zero or above zero.
High-power audio without the quiescent power loss.
I can also make a class G H version up to about 14K400 Watts.
The improved amplifier actually turns on / off the current source / sink so only one is on at a time, 25mA from +/- 15 Volt rails.
A voltage comparator detects output voltage below zero or above zero.
High-power audio without the quiescent power loss.
I can also make a class G H version up to about 14K400 Watts.
So the name Goat Electronics Ltd on the diagram is merely there to confuse us? And the diagram is of the older design which doesn't work except by accident?
How do you ensure that the zero crossing detector always works exactly as it should in real life?
People often put up amplifier designs which work well in Spiceworld, but fall flat on their faces in the real world of poor device matching and non-resistive speaker loads.
How do you ensure that the zero crossing detector always works exactly as it should in real life?
People often put up amplifier designs which work well in Spiceworld, but fall flat on their faces in the real world of poor device matching and non-resistive speaker loads.
Hello coldrunning2002. It may beneficial to the audience to superimpose on a [simplified] schematic of your choice the resultant signals [or pulses] at key locations of it. By example, start with a 10 Vp-p input 60Hz signal. Track the amplitude of the pulses and especially their duration at their zero crossing relative to 16.7 milliseconds per 1/2 cycle of the 60 Hz input signal.
How much amplitude and time is this amp "shaving-off" from an otherwise pure Class B style pulses? Thanks.
Best
Anton
How much amplitude and time is this amp "shaving-off" from an otherwise pure Class B style pulses? Thanks.
Best
Anton
Hello PRR. I experiment with Class B under another name I gave it [Class aP]. [aP] stands for analog pulse. [aPs] are generated from an AC input signal by using an OpAmp precision rectifier. This approach minimizes or eliminates crossover distortion early on in processing. The resultant pulses are thereafter presented to the power output semiconductors or tubes for amplification ONLY. Preferably the power devices idle at several mAs so to get them conducting; but they do not crossover!
I can see your meaning of biased hard-OFF "C". It is a ready-option to experiment with in Class aP amplifiers. This thread is in the Pass Labs Forum.
Best
Anton
Yes agree, the amplifier must source & sink maximum current at all voltage levels especially between -1.000 Volt and +1.000 Volt
Hard switching current sources will also cause regulation problems; the current sources need to be blended in & out.
So it is not going to work with loudspeakers, maybe it will work with piezo tweeters.
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