They have arrived, PA150!

[CJ900RR]

My goal to create my own version of the PA150 is on it's seccond stage. As allways it started with some (read many) hours in Eagle.



I wanted to achive a good design that would be easy to assemble in a case when doing a bridge amplifier. Therefore the inputs and outputs are on both left and right side of the board. Some components should be left out depending on from which side you connect power, input etc.

They use servo-circut to null the DC-offset instead of trimpot's, so a +/-15V is needed.



Today, 10 PCBs arrived from China (www.pcbcart.com, excellent supplier).



They have NOT ben assembled yet, and therefore NOT TESTED. Sorry for poor quality on photo. Only mobile-cam avaible right now. If they work, I will order more boards and sell them if there is an intress. But as said, I need to test them first.

Size is 6.5 x 2.5 inch, or 16.5 x 6.35 cm.

[CJ900RR]

One thing only. I uploaded wrong gerberfiles to pcbcart so there is no onboard zobel network on the boards... im a bit clumsy

[rikkitikkitavi]

by accident I was going through my boxes with electronics and found a tube with 6 pcs of LM3886...

this looks nice

[CJ900RR]

Then this might suit you well then I will start assembling on monday at work..

[AndrewT]

Hi Cj,
does each chipamp need it's own output Zobel or does the parallel amp set up only need one Zobel between the summed output and the speaker terminals?

[CJ900RR]

Originally posted by AndrewT
Hi Cj,
does each chipamp need it's own output Zobel or does the parallel amp set up only need one Zobel between the summed output and the speaker terminals?

Hi Andrew.

I think that each PCB only need one Zobel between the summed output. The layout with servo-circuits, "snubber"-caps and decoupling-caps that will be soldered directly to the supply pins combined with well matched components should give a stabil construction.

I you have other opinions please feel free to say so

[peranders]

I would personally put the zobel close at each output.

[coldfuzion76]

Just curious how things are going on this one. I too want to build the pa-150 and was wondering if there might be a group buy after you get the kinks worked out. I missed out on the last one.

[CJ900RR]

Originally posted by coldfuzion76
Just curious how things are going on this one. I too want to build the pa-150 and was wondering if there might be a group buy after you get the kinks worked out. I missed out on the last one.

Things are going well i think. Test will follow later this week, if im lucky allready tomorrow. There will most likely be no groupbuy but i will offer them for sell at my webpage.

Better photo below.

[CJ900RR]

This will be the "real" design i guess. Zobel netwok on pcb as wanted by some. Personaly I dont like the Zobel, I think it has an interference on the sound, but this way people are able to use it if they want.