AB100 Class AB Power Amplifier

[Freecrowder]

So do not consider myself the expert on amp matters. Listen to others for sure. But if your talking about increasing levels of even harmonics compared to odd orders, push pull output stages tend to reduce even order more so than odd. It is inherent in the push pull stage. Now I believe it might be designed to be somewhat unbalanced which might increase even orders. Not sure though. Usually you wouldn’t do that. Will wait and see what the experts think.

We are so lucky to have this site. All the knowledge that gets shared!!

 

[Jacruzer787]

So do not consider myself the expert on amp matters.

Neither am I brother. Just curious!

if your talking about increasing levels of even harmonics compared to odd orders, push pull output stages tend to reduce even order more so than odd. It is inherent in the push pull stage. Now I believe it might be designed to be somewhat unbalanced which might increase even orders

I just checked the docs for the F5M and I think its push pull, but pa said it has even order negative phase. So I think its right that usually push pull tends to do that, unless you are pa and you do what you want. 😂

I am prepared to stand corrected.

 

[Freecrowder]

Oh for sure if NP is saying it then I trust that. I need to read up on what he is doing there. Read it in the past but forgot it now. I remember a pot that he would tweak. Maybe introduces some imbalance in output stage. I think that would make even orders go up some.

 

[Jacruzer787]

I remember a pot that he would tweak. Maybe introduces some imbalance in output stage. I think that would make even orders go up some.

🤷‍♂️I should probably learn how to read schematics. Mostly just from what I read and the burning amp talk.

 

[Nelson Pass]

Actually it's the result of the P ch mosfet having lower transconductance than the N channel.

In the ACA mini I included an optional RC network in series with the Source of the P channel device to reduce the 2nd harmonic.

(If you want that...)

 

[Jacruzer787]

Actually it's the result of the P ch mosfet having lower transconductance than the N channel.

In the ACA mini I included an optional RC network in series with the Source of the P channel device to reduce the 2nd harmonic.

(If you want that...)

Thanks pa! So is this only possible in class a?

 

[jamesfeline]

Hello

Just wondered if we can get hifi2000 (modushop) to provide a pre drilled heat sink for this

 

[jamesfeline]

hello jk556,
here are the updated gerbers as per the above quoted post.
no major changes except option for 2 big 35 mm caps instead of 4 smaller caps and doubling up of traces at some places.

Hello Prasi

hope you are well I am trying to get the heatsinks pre drilled by modushop would you have the DXF or DWG file for drilling
many thanks

 

[jamesfeline]

I only have this currently

 

[Gianluca]

A PDF file would work too as long as all the dimensions are indicated

 

[jamesfeline]

this is the gerber file that I am using .. assuming its the latest

 

[Gianluca]

I cannot open this kind of file

 

[asuslover]

Extra boards for sale? Thanks

 

[prasi]

Hello Prasi

hope you are well I am trying to get the heatsinks pre drilled by modushop would you have the DXF or DWG file for drilling
many thanks

Hi James,
its been so long, so i dont know if the one shared is correct or not, but looks alright.
but since you shared gerber , here is latest. it might be same as the one you shared.

so i attach pdf 1:1 and dxf file.
hope this helps
regards
prasi

 

[jamesfeline]

many thanks

 

[jamesfeline]

the drill template that I have currently is

 

[jamesfeline]

Hi James,
its been so long, so i dont know if the one shared is correct or not, but looks alright.
but since you shared gerber , here is latest. it might be same as the one you shared.

so i attach pdf 1:1 and dxf file.
hope this helps
regards
prasi

Hello Prasi

I am working with modushop ( Gianluca who has been very helpful) but the dxf file needs to show the actual drill points assuming 3 mm threaded holes for the PCB spacers as per the attached pdf file
would you have the dimensions to add for actual drill points
this would be greatly appreciated

 

[prasi]

My bad... I should have opened the file and checked for the hole dias and shapes.
please refer attached file.
I have shown the hole dia/radii..
However, the heatsink needs to be drilled 2.5mm for all holes for tapping of M3 size, modushop guys know better.
And since its a dxf file, the relative hole locations can be measured in any CAD software like nanoCAD or freeCAD.
regards
prasi

 

[Gianluca]

Thank you Prasi, this is perfect

 

[jamesfeline]

many thanks .. well done