[~n00beR]

Hello all, it has been a long time since I last posted

I have had much success copying other people layouts and following other schematics.

However now its my turn

Its a simple ground buffered cmoy, thought i would start on something simple and work my way from there, I can add buffers and biasing later.

Could anyone comment on the layout?
The input capacitor will be added if necesary.


If the schematic and later layout, are ok, I will hopefully use this for opamp rolling.
Hence the missing popular buffers, these will come later (hopefully).

 

[FallenAngel]

The schematic looks ok, just two things for the ground channel.

1) Why would you connect input ground to output ground? I don't think you're supposed to, it kind of bypasses the whole ground channel doesn't it?
2) R3G is only necessary for bipolar opamps, FET opamps don't need it.

Good luck with the build, please post pics when done.

 

[jbloudg20]

Yeah, don't ground the ground channel.

 

[~n00beR]

Thanks for the input guys. I have updated the schematic.

Now busy beavering away at the pcb

 

[jbloudg20]

Looking forward to the results!

 

[~n00beR]

OK here is what I have so far.

Any comments on the layout would be greatly appreciated.

 

[Pars]

Hi,

Looks pretty good. You could shrink it some by rotating and moving some caps:

E27: rotate so the terminals are as E26's are. (sorry, I don't see any C ref #s for these, so using the closest label)

E22: I would rotate this 180 degrees and put it on the end (below) of the film cap (E19?)

Same thing with C3/E20... I would move the input film cap by IL and rotate it 90 degrees, then cram the electro in below the power pin and film cap (E20?)

I'd then compress the layout horizontally. I would also put a board mounted pot (Alps RK097) on, and if it were me, the input output jacks also. I also don't see pads for the power input...

Chris

 

[~n00beR]

Thanks for the input Pars.

I have implemeted your suggestions.
You were right there were no power input pads, but I waswondering if anyone had any input before I progressed.

The large area in the bottom right will be used to lie the power caps on their side, depending on what case I eventually decide upon, but it will most definatley be externally powered

Does this look ok now?

Thanks again of the input.

 

[ATAT]

1. Bigger crowbar diode.
2. You're cutting the groundplane... jut have the bottom ground and try and route everything on top or vice versa
3. so much wasted space on the right... trickle charger using LM317?

 

[j4cbo]

Run a DRC and fix all your airwires.

And what's with the V- trace going to the pot?

 

[~n00beR]

Quote:

Originally Posted by ATAT /img/forum/go_quote.gif 2. You're cutting the groundplane... jut have the bottom ground and try and route everything on top or vice versa

This will take me a while, but i will give it a go

If i don't find it possible would it be better without a groundplane at all?

Quote:

Originally Posted by j4cbo And what's with the V- trace going to the pot?

The pot has an integrated power switch.
It was easier to route the -V supply than the +V supply that is all

Thanks for the input.

Back to Eagle

 

[~n00beR]

This is the current itteration.

I managed to get all but one of the traces on the top side. and its only a small via trace.
If some one can see a better route for the remaining trace please enlighten me

.

What do people think now?

The visible ground plane measures 3" long and 2" wide.

No in/out jacks as I plan on panel mounting them, the same with the power connectsions

Thanks for the input so far, you have a ll been a great help