SMD Chu Moy

[Devil_H@ck]

2 days ago, I bought roughly 2800 SMD parts (resistors, caps, other stuff, all thrown together) from eBay for only €25 (including insured shipping), so I decided I needed to do something with it once the parts get here.

The Chu Moy has been my circuit of choice more than one time for testing purposes, so I decided to use it again. To add some extra difficulty and "coolness" I also decided to try a double sided PCB (since I'd bought a small one for testing a few weeks ago). I routed this in about an hour, so I'm sure it can be done better, but still, it's got a star ground, so that's something.

I haven't got the SMD parts yet, so no pictures of the finished circuit yet.

The PCB size is 1.8cm x 2.6cm. It came out almost perfect (except for some text with traces less than 3mils wide, another text with traces 3 mils wide came out perfectly though). The transparencies for this were made with a laserprinter, I tried to print it with an inktjet, but it just wasn't up to the job. I only had a bit of trouble with the drilling, since I still do it by hand and it had to be perfectly straight. The first 3 holes are a bit angled, but all the others are nice and straight, right through the pad on the other side of the PCB.

Anyway, here are some pictures. First the top layer:


And the bottom layer (you can see tiny spots of copper in the upper right, that's the text that failed to etch correctly):


I also put it on my website, but there isn't a lot more info on the page than there's here: http://members.lycos.nl/anthonyvh/in...age=chumoy-smd

*In case you don't know what the Chu Moy amp is, it's really just an opamp with only the necessary resistors (kind of like a gain clone ). Here's the "official" page: http://headwize.com/projects/showfil...=cmoy2_prj.htm

I don't use the rail splitting method with resistors though, I use a TLE2426 (Texas Instruments), which is better. Opamps will be OPA134 or OPA227.

[gigatron]

cool

[maxw]

Yes, cool
Post more pics when you have components mounted etc

[carlmart]

Originally posted by Devil_H@ck

Anyway, here are some pictures. First the top layer:


And the bottom layer (you can see tiny spots of copper in the upper right, that's the text that failed to etch correctly):

What pictures? I can't see any. In fact I can't even access that site. What can be the problem?


Carlos

[maxw]

Originally posted by carlmart



What pictures? I can't see any. In fact I can't even access that site. What can be the problem?


Carlos

Must be a problem local to you. I can see them fine.
See attachment

[Devil_H@ck]

It's cool you guys think it's cool . I'll sure post pics when it's finished! I won the eBay auction 2 days ago, but the payment is international wire transfer, so I'm not sure if the seller's received the money yet. Once she does I guess the SMD stuff should be here in 2-3 days. So, expect some more photograps next week .