learning to vero. need one checked please

[whomeno]

did a vero from this schematic for a lm3886. not using pin 8 mute. would this vero work?

[Travis]

The layout image is too small/low res to read. Use an image editing program (including MS Paint) to crop away the excessive empty space

I looked at a couple datasheets and they are a little vague about the pinout. It looks like they are staggered, I’d have to find a more specific datasheet

[whomeno]

yes the 3886 is like the tda7240. updated the pic
Thanks

[Travis]

It is a great first effort, but the way you have done things is a little convoluted.

There are several cuts doing nothing at all and an excessive amount of links. For example the cuts next to Q1, 220pf, 10uf, and pin 1 are not doing anything. The link next to the 75k could easily be removed and move the top leg up one row

The top leg of the 91K should go to the row with V+/pin 1. The bottom leg of the 75K should connect to the base of Q1

You almost got that feedback network right, but the 2.7Ω should connect directly to pin 3, not the output

A couple tips.. you have made Ci a 10uf film cap. There is not a 10uf film cap that will physically fit your layout. You labelled 3 caps “0.1uf” and one “100nf”. I would pick one convention and stick with it.

The cap labelled 100nf is generally pretty small to use as a decoupling cap. You’d usually see more like 100uf maybe with a 100n ceramic cap in parallel. This filtering is most effective when it is right next to the IC pin. It is somewhat bad practice to connect the filtering further from the IC pin through a link but this isn’t necessarily critical. Likewise it would be better to connect your ground directly to pin 4 but again this is not critical

[amsterdam]

just got a bunch of these in the mail the other day!! https://www.taydaelectronics.com/10uf-50v-multilayer-ceramic-capacitor-x7r.html

[Travis]

How did I forget about those? Thanks for pointing that out

[whomeno]

Travis
Thanks for the feed back on the layout. I want to do the vero's myself instead of asking for it to be done for me. I made all the corrections except for the 2.7 R not sure how I could get it closer and the decoupling cap


"The cap labelled 100nf is generally pretty small to use as a decoupling cap. You’d usually see more like 100uf maybe with a 100n ceramic cap in parallel."

so use a 100uf Electrolytic and a 100n ceramic cap in parallel ?

[Travis]

As you get more comfortable making layouts you will find yourself moving things around a lot like Tetris

The easiest way to move the 2.7Ω to pin 3 would be to move the cathode of the 47uf up to the row that pin 5 is on (adding a cut of course). Then move the 10Ω 2W, output wire, and cut one row up. At this point the 2.7Ω is going right to pin 3 as long as there isn’t a cut breaking that path

Btw as I was just looking at it, I noticed an unwanted cut between the 47uF and 2W resistor. You probably would have noticed as you moved these things but I figured I should point it out just in case

And yes anything like 47uF-100uf+ is commonly used for power filtering/decoupling. If you look at IC datasheets they usually recommend a value, but you shouldn’t go wrong with a 100uF electro and 100nF ceramic

[whomeno]

Thanks for all the help