I know about breakdown and quasi-saturation. It doesn't seem breakdown is an issue for attentive designers, but quasi-saturation is a blind spot in simulation. Luckily LTSpice allows some basic quasi-saturation parameters, but I tried to use them and when combined with the inadequate high-current rolloff slope, it seems impossible to get a realistic quasi-saturation curve.
- keantoken
- keantoken
Alex can you post this tonight so I will etch the new board tomorrow?
Thanks!
Regards!
No problem 🙂 snow was also a big problem here.
It seems that 33pF cap in the VAS and 100pF cap in the input are missing again.
Regards!
It seems that 33pF cap in the VAS and 100pF cap in the input are missing again.
Regards!
Signal ground seems to be disconnected from power ground. Also the feedback point isn't at the output point.
Signal GND is disconnected only on the picture on the .pdf file is correct.
You are right for the feedback point but no big deal I think 🙂 don't be super pedant please...🙂
Capacitors are the main problem and I hope that will be corrected.
Kind Regards!
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Because the last version of the PCB have just a small error I decided that I can fix it by my own. So played a bit with Photoshop and MS Paint and was done - was really easy 🙂 Also I etched a new PCB today and tomorrow at least will build the VER 2.0 🙂
Attaching the fixed PCB.
Regards!
Attaching the fixed PCB.
Regards!
Attachments
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Version 2.0 Completed...
Today I finished Ver2.0 🙂
Everything went fine - powered up , adjusted bias and offset and listened.
There were no hum and hiss it is death silent.
This amp seems to be very good it has a bit better trebles than my older one and there is big improvement in the bass reproduction so this amp can be used successfully as SUB amp. Trebles and detail are also good and I think this is an excellent HI-FI amp.
I want to say BIG THANK YOU to everyone who helped and guided me trough all this , showed me the problems and their possible solutions and have been patient enough to explain me some stuff that I don't know. You guys are the best in the world
Here are some pictures.
Wish you all the best.
Today I finished Ver2.0 🙂
Everything went fine - powered up , adjusted bias and offset and listened.
There were no hum and hiss it is death silent.
This amp seems to be very good it has a bit better trebles than my older one and there is big improvement in the bass reproduction so this amp can be used successfully as SUB amp. Trebles and detail are also good and I think this is an excellent HI-FI amp.
I want to say BIG THANK YOU to everyone who helped and guided me trough all this , showed me the problems and their possible solutions and have been patient enough to explain me some stuff that I don't know. You guys are the best in the world
Here are some pictures.
Wish you all the best.
Attachments
Last edited:
Thanks Mooly! 🙂 Alex's PCB's are great for sure....🙂
It is not perfect but it is made in the true DIY spirit - everything that I can made it by myself. Even my etching solution was DIY...🙂
Regards!
It is not perfect but it is made in the true DIY spirit - everything that I can made it by myself. Even my etching solution was DIY...🙂
Regards!
..... Hmmm
.... no work , no mistake , no smoke 🙄 and so on .At least I did something in this thread , and thanks to all for kind words. I'm glad my layout PCB was useful ,
Alex.
.... no work , no mistake , no smoke 🙄 and so on .At least I did something in this thread , and thanks to all for kind words. I'm glad my layout PCB was useful ,
Alex.
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Absolutely true Alex!
Your PCB is a piece of art and it is the main reason actually to make my first board. When you posted it I was amassed of it was so beautiful you have a gift to produce compact and nicely arranged boards that I've never seen and your work is my inspiration. I wish one day to be able to make boards like you but this probably won't happen as I said it is a gift that belongs to a small amount of people and I'm happy to know one of them. Thanks again for your work
I never even dreamed that someone will do something like this for me just like that for fun.About mistakes don't worry I'm the main reason for them because posted wrong schematic and again you were kind enough to fix them. Of course no work no mistake the only reason to try to fix them is because someone may decide to build this project and looking the picture may put the wrong part at the wrong place and all will end up in smoke and this is when the disappointment comes. I never wanted to offend you because posting this fixes just to prevent damages and I hope you don't mind because of this.
Be happy and continue to make your pieces of art.
Wish you all the best!
Second Channel Ready...
Second channel is ready too 🙂
Again everything went fine. Excellent result. No problems during testing at all.
Now I need to buy most expensive parts - the transformer and the heatsink.
What heatsink will be good for me? Amp will mostly run on 8R loads and I think 100W of power will be more than enough for me. Bias will be 125-150mA.
For trafo will use toroid 300VA 35-0-35VAC it will be good enough I think.
Any suggestions?
Here are some pictures 🙂
Second channel is ready too 🙂
Again everything went fine. Excellent result. No problems during testing at all.
Now I need to buy most expensive parts - the transformer and the heatsink.
What heatsink will be good for me? Amp will mostly run on 8R loads and I think 100W of power will be more than enough for me. Bias will be 125-150mA.
For trafo will use toroid 300VA 35-0-35VAC it will be good enough I think.
Any suggestions?
Here are some pictures 🙂
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