Should I try again on PCB's or go for perfboard?

[Spasticteapot]

After much headaches, I'm getting fed up with trying to make my own PCBs. Perfboard, however, proved to be a nightmare; my attempt at a perfboard amp did not work at all, and the LM3875 CPU I'm using does'nt fit in the pre-made holes. I can't use stripboard for this reason, too.
Can anyone give an example of how to make a gainclone on perfboard, or perhps a better way to make PCBs? Chipamp.com's PCBs won't fit my parts, so that's not an option.

[rabbitz]

If you haven't got etching experience, then get a Dremel out and cut some tracks.

This one's a LM3875.

[rabbitz]

... and the other side.

[lgreen]

Click my signature line link below (or here) to see my LM3886 efforts via perfboard, which I then disassembled and made via a premade PCB.

Long story short- perfboard is not as neat nor as easy but it feels like you did more work and it seems as if its more your own. I kind of regret going to the "store bought" boards from a satisfaction standpoint. However, I found my abilities to make solid connections on perfboard to be less reliable than with a pcb.

These chips will fit a perfboard if you jiggle the pins around a little, don't be content to stay with their original spacing. They don't protrude very much but if you are slow and deliberate you can hook it up. If some pins are annoying feel free to lift them up and connect NASA style- "in the air". Lots of people have chipamps with no board at all, but with R's and C's carefully soldered to the pins freestyle. Nuuk?

Rabbitz has offered some fascinating advice- get copper clad board and carefully drill some holes and etch copper away with a dremel. Wow, sounds really neat.

So to answer your question- stick with perf if you cannot easily find a pcb for your particular chip using the methods above. But if you continually fail go ahead and get the board if you can find it.

[billdinva]

I am currently testing a dual OPA2134 preamp, DS1802 pushbutton digital vol/bal control, and two 3875's on a 3x3.5 strip board. For the 3875, remove the N/C pins 2,5,6,9,10, then bend the pins into a single line. Mount the 3875 on the edge of the board. I mounted the 3875 on the right edge of the board. I put pin 1 (V+) in row I, pin 3 (output) in row J, pin 4 (V-) in row K, skip a row, pin 7 (Vin+) in row M, pin 8 (Vin-) in row N, skip a row, pin 11 (n/c) in row P. The other alternative is to mount the 3875 at a 45 degree angle to the holes with very minor bending. The other options is to have some custom made PCB's. Depending on the PCB house, the minumum order can be as low as 3 boards for US $51 + shipping

[Greg Erskine]

Front.....

T-network IGC from memory. Note caps are only 100uF.

[Greg Erskine]

Back....very ugly, very small - only 6 x 10 holes.

[DolbyR]

The dremel method is good, i was using it before i found perfboard, and great for simple boards. the other method ive used i found in some gainclone site, its cutting the paths with an X-acto knife and after that just heat the copper u want to remove with ur soldering iron, comes out quite nice too.

[12 Cents]

If you mount the chip in a 45 degree angle, the pins fit the holes quite closely. So cut an edge of the perf board, then that is where the heatsink goes, I can post a pic tonight if desired...

[Spasticteapot]

Thanks for the help!

I've made up a pair of PCBs, but they're not terribly good. I might try the stripboard method, though.

I'm currently stuck away from a soldering iron and my stuff for a week, though, and I'll have to tell you if they work. (If they do, I'm having Olimex make me up a dozen of 'em. At 2$ each, what's not to like?)

I do like the look of the "dremel etched" PCB, too.

Thanks for the help!