View attachment 1001376
I changed the circuit somewhat so we get with and input voltage of 430mv P-P and output swing of almost 5 Volts RMS into 8 Ohms.. Blue Line input White Line Output
Please note I took some other transistor in my Simulation Program, because 2SC5200 is not found in Multisim 14. So I took MJL4281 and MJL4302 which are very close to 2SC5200 and 2SA1943
I also give it a Negative RAIL VOLTAGE /12 Volts *VEE* then we can operate it without output Cap or with Output cap as well..
Yes the second one looks better to me too..
check out the pictures.. Wave isn't fascinating a beauty, but with some time on the hands and the will to change there could done many things..
Cheers Guys..
I changed the circuit somewhat so we get with and input voltage of 430mv P-P and output swing of almost 5 Volts RMS into 8 Ohms.. Blue Line input White Line Output
Please note I took some other transistor in my Simulation Program, because 2SC5200 is not found in Multisim 14. So I took MJL4281 and MJL4302 which are very close to 2SC5200 and 2SA1943
I also give it a Negative RAIL VOLTAGE /12 Volts *VEE* then we can operate it without output Cap or with Output cap as well..
Yes the second one looks better to me too..
check out the pictures.. Wave isn't fascinating a beauty, but with some time on the hands and the will to change there could done many things..
Cheers Guys..
Attachments
Last edited:
I built the second schematics. I used bc550 for input bjt. I flipped polarity of output cap, because there is ~2 volts negative where the 10 ohm resistors join. Input cap is ok, because base of first bjt is negative due to those two 4k7 series resistors.
Now, the fun part, at low level it actually sounds rather good. It can fill the room easily with pleasant sound, what a surprise. If i push it, it distorts, off course.
My guess first bjt is overloaded. I do not understand why input base needs to be tied to negative rail.
I may measure it later. Maybe even mod it.
Need to finish whammy and acp+ first.
Now, the fun part, at low level it actually sounds rather good. It can fill the room easily with pleasant sound, what a surprise. If i push it, it distorts, off course.
My guess first bjt is overloaded. I do not understand why input base needs to be tied to negative rail.
I may measure it later. Maybe even mod it.
Need to finish whammy and acp+ first.
Sadly not everything on the net is correct.
I designed a USB oscilloscope and wanted a spectrum analyser screen too.
So looked around for a fast fourier transform to convert time display into frequency spectrum.
I tried 5 different ones before I got one that worked well.
I was having some more fun with c5200/a1943 outputs.
Here is what i did. I abandoned the input transistor, as i believe its a messed up design, and used only the output stage.
Then i modified bias adjustment, separate for negative and positive rail. I used 10k as satety, and 30k trimmer for adjustment.
Then i used 0.22 ohm emitter resistors to easily monitor the current.
I used bipolar cap on input and output as i did not want to bother with polarity.
Here is test circuit.
Here is what i did. I abandoned the input transistor, as i believe its a messed up design, and used only the output stage.
Then i modified bias adjustment, separate for negative and positive rail. I used 10k as satety, and 30k trimmer for adjustment.
Then i used 0.22 ohm emitter resistors to easily monitor the current.
I used bipolar cap on input and output as i did not want to bother with polarity.
Here is test circuit.
Attachments
I used standard fw power supply, +/_22 volts. I used variac, and tested all with lower volts first. I could use bigger supply, these transistors can handle up to +/_80 volts, but why.
This is just for fun.
With 30k trimmers i adjusted bias, started with lowest, trimmer at max resistance, and to highest current with trimmer at 0 ohm. 10k ohm is still limiting as high as it could go. Plus i have small heatsink.
Four measurements were done, at moderate sound level, with speakers plugged in. About 0.5 watt as i do not like it too loud.
Measuring voltage dropped on 0.22 ohm resistors, i ended up with theses currents in the stage: 0.086A, 0.136A, 0.309A and 0.591A.
Here are the distortions measured.
This is just for fun.
With 30k trimmers i adjusted bias, started with lowest, trimmer at max resistance, and to highest current with trimmer at 0 ohm. 10k ohm is still limiting as high as it could go. Plus i have small heatsink.
Four measurements were done, at moderate sound level, with speakers plugged in. About 0.5 watt as i do not like it too loud.
Measuring voltage dropped on 0.22 ohm resistors, i ended up with theses currents in the stage: 0.086A, 0.136A, 0.309A and 0.591A.
Here are the distortions measured.
Attachments
Some update. As ZM had in another thread poignant remark that my focusrite can not provide enough current to drive outputs, i made some mods.
I coppied unabashedly output from fm acoustics power amp, where they use c5200 to drive c5200...long story short, it works.
Here is the pic. More later.
Now this is going to be serious classA buffer with no negative feedback. I need bigger heatsink.
I coppied unabashedly output from fm acoustics power amp, where they use c5200 to drive c5200...long story short, it works.
Here is the pic. More later.
Now this is going to be serious classA buffer with no negative feedback. I need bigger heatsink.
Attachments
These web sites illustrate a bigger issue. Are they harmless? Are they just incompetence or fraud, or both? If they didn't have so many errors and used cheap parts appropriate for disposable use, then they wouldn't bother me. If you are going to make a 3W amplifier, I would suggest $0.25 transistors, not $2.50 transistors. Maybe the point is that it's hard to destroy a 2SC5200 with a 24V @ 2A power supply? Claiming ridiculous performance numbers is fraud.
Hey, lets forget those bogus sites for now.
I am going to come up with something which is claasA buffer, 100% verified, as iam using genuine parts.
Lets forget everything.
I am building claasA amp like jungson or fm acoustics, step by step...ok, measuring, listening.
Yes, listening, as is it sounds amazing righ now.
Just your headphone output of your favourite cd player to output stage!
Bang! It souds fabulous.
Wait for more development.
If i do not beat f4 i will retreat to my beach house in belize.
I am going to come up with something which is claasA buffer, 100% verified, as iam using genuine parts.
Lets forget everything.
I am building claasA amp like jungson or fm acoustics, step by step...ok, measuring, listening.
Yes, listening, as is it sounds amazing righ now.
Just your headphone output of your favourite cd player to output stage!
Bang! It souds fabulous.
Wait for more development.
If i do not beat f4 i will retreat to my beach house in belize.
Well, if you connect diodes the proper way, add a-12V rail, or even better a +/-22V supply, tweak the driver, then results wi9ll be better .... but what relation does it have with the original circuit?
The one which had 1.5 Million views and > 20000 likes 2 Months ago?
THAT is the famous one, followed by Millions, and works as bad (horrible) as the first day.
This reminds me or the famous George Washington axe which is being carefully preserved in a Museum.
"Kids (said the Guide), this is the ORIGINAL George Washington axe. ...... SO important that we regularly do preventive maintenance ... the head has been replaced 5 times, and the handle 9 times ,,,, but it´s the original because we never fully replaced it by another"
Same here ...all that was kept was the power transistor pair ... which was grossly overspec´d from the beginning
.
By the way, It DOES work (sort of) in the original diode configuration.
Too sleepy now for a description, if somebody finds how he´ll earn a late model IPhone, how´s that?
The one which had 1.5 Million views and > 20000 likes 2 Months ago?
THAT is the famous one, followed by Millions, and works as bad (horrible) as the first day.
This reminds me or the famous George Washington axe which is being carefully preserved in a Museum.
"Kids (said the Guide), this is the ORIGINAL George Washington axe. ...... SO important that we regularly do preventive maintenance ... the head has been replaced 5 times, and the handle 9 times ,,,, but it´s the original because we never fully replaced it by another"
Same here ...all that was kept was the power transistor pair ... which was grossly overspec´d from the beginning
. By the way, It DOES work (sort of) in the original diode configuration.
Too sleepy now for a description, if somebody finds how he´ll earn a late model IPhone, how´s that?
Point is NOBODY is interested in 3W amps and to boot with cheap TO92 transistors because that does not impress anybody, emphasis on IMPRESS.
While
dramatically rises blood pressure, cardiac rhythm, produces a HARD D.......etermination to build it, etc.
SPIKE protein of the fake amp virus which makes it stick to Millions?
The magic words:
- one-thousand-four-hundred WATTS!!!!!!!!!!
- POWERFUL BASS!!!!!!!
