Pavel, I must say that I'm kind of surprised. 2000 people have downloaded your schematics and layout now. Impressive! 
Lot's of the downloads are of course "noise" but I think there is a sincere interest in your design. Mr Daniel's and Mr. Bells' concept is one flavor and yours is an another. Nobody is right and nobody is wrong.
Lot's of the downloads are of course "noise" but I think there is a sincere interest in your design. Mr Daniel's and Mr. Bells' concept is one flavor and yours is an another. Nobody is right and nobody is wrong.
The number of parts is of no importance. What is the most important is the circuit and the PCB design. Pavel Dudek has done great work and he gained from that LM chipamp everything that can be gained.
It has, as a matter of fact. Many parts increases the probablity to failure but if we talk sane amounts of parts I agree with you. 🙂PMA said:
I know you understand what I mean and I thank you for clarification for the others 😉 . On the other hand, component redundancy (e.g. 2 resitors in parallel in series with further 2 resistors in parallel - instead of one resistor) may increase reliability 😉 .
Has anyone else beside Pavel built an amp based on Pavel's design?
Eventually has anyone compared this design to the brian/peter's design(only sound quality the other stuff out of comparison please)? If so, could you share with us how you find it?
I am really looking forward to hear more about this. Also a group buy if enough people are interested would be a great idea.
I don't think either one is better until someone does a good and fair comparison and even then, some might like one version and some others the other one. Beside it is stupid fighting :/
Eventually has anyone compared this design to the brian/peter's design(only sound quality the other stuff out of comparison please)? If so, could you share with us how you find it?
I am really looking forward to hear more about this. Also a group buy if enough people are interested would be a great idea.
I don't think either one is better until someone does a good and fair comparison and even then, some might like one version and some others the other one. Beside it is stupid fighting :/
roibm said:
I haven't even gotten the boards made yet for Peter's/Mine pcb layout, so I doubt anyone has compared the two designs.
--
Brian
Pavel promised to send me one of his boards, so I will have a chance to compare. I will also send him our design, so he can do the same (and I will include those "exotic" parts that P-A makes jokes about)😉
This is a brand new PCB design that Pavel has made. We were listenning to it for the first time here as Pavel described several days ago. I was quite surprised by the sound quality of Pavel's module. For the chipamp it is fanatastic and can beat many of the discrete amps. But a few of the very good discrete amps are still better.
Chipamps have their limitations that cannot be neglected. But they can be recommended as quite a simple way to good result, if done properly.
Chipamps have their limitations that cannot be neglected. But they can be recommended as quite a simple way to good result, if done properly.
Attachments
Pavel is hosted by me until he gets his own homepage, free of charge of course. I think Pavel deserve to be put forward.
My host is www.b-one.net for 1.45 dollar a month. Excellent host!!!
My host is www.b-one.net for 1.45 dollar a month.
Excellent host!!!
The schematic doesn't include the values of most of the parts so not much coments do do...
But from what I see, many things could be removed, some things could be included and some things could be made in a different way for a much better sound.😀
Ooopps...
Sorry, seams that I'm alone here...
Everyone agrees this is a very good PCB and a very good amp, right?😕
But from what I see, many things could be removed, some things could be included and some things could be made in a different way for a much better sound.😀
Ooopps...
Sorry, seams that I'm alone here...
Everyone agrees this is a very good PCB and a very good amp, right?😕
Carlos, could you speak in more concrete terms? I would substitute Pavel here.
From my point of view, it was very wise that he included input opamps into the design.
From my point of view, it was very wise that he included input opamps into the design.
PMA said:
Of course it was!
I use them too.😎
Much better with them than without them.
Without knowing many of the components' values (including PSU caps), allow me to make some suggestions based on my experience with GCs (yes, I tested all that you can think about, except valve buffers).
- Input op-amps yes yes yes! OPA627 (non-inverting).
- LM4780 - yes, very good, but I would use it as inverting, it's the best combination: NInv. input buffer + Inv. amp.
- Change that dreadful zobel by two paralleled 0.47 ohm/3watt resistors in series with the output, much better.
And... last but not least:
- Change the PSU caps on the LM4780 for 33~100uf and regulate the PSU with LM338.
tbla reports very good results too with LT1083.
BTW, trafo with independent secondaries and two bridges.
😀
But I would have one comment. You MUST keep signal polarity of the amp as a whole. It makes difference if you invert it. At least loudspeaker wires should be turned when using non-inverting OA + inverting LM.
PMA said:
Of course.
Forgot to say.
I invert the wires inside the amp.😀
+ speaker terminals connected to ground and - speaker terminals to output.