"Little Angel" - Super Simple PT2399 Mini Chorus

[p_wats]

Hey guys, I tried a perf/p-to-p layout for this, but it's only my second time ever going from schematic to layout, so I screwed up somewhere and I get nothing but a faint hum. Can anyone see anything glaringly wrong at a glance?

[culturejam]

Pins 3 and 4 should be grounded, not just connected to each other.

Pin 4 is the analog ground, and if it ain't grounded, you don't get sound.   

[p_wats]

Pins 3 and 4 should be grounded, not just connected to each other.

Pin 4 is the analog ground, and if it ain't grounded, you don't get sound.   

Thanks for the catch. That's just a drawing error though, as I actually did ground pin 4 when I perfed it...so there's probably something else keeping it from working.

[culturejam]

I think I see the problem.

The 470K resistor should connect directly to pin 6 of the op amp. You have it connected to pin 7.

[JKowalski]

no wonder your etching technique is superb because you design them in illustrator which is vector based as opposed to photoshop pixel based..

Photoshop does vectors too! Even on my now-very-old photoshop 7 that can't install on windows 7. 

[frequencycentral]

.....and the PCB apparently will fit in a 1590A! This might well be my excuse to try my hand at a 1590A build. solderman? danielzink? valoosj?

I don't wish top be a party pooper but...
I have to report that I do not believe this will fit into a 1590A.
The board is exactly as wide as the outer dimensions of the enclosure. While you could perhaps lean the board I do not believe you would have room for the footswitch and especially jacks with a leaning board.

I will say it will fit a 1290 very nicely however.

If someone can prove me wrong...(Daniel Z. ?) .. I will certainly tip my hat to you!  

Shock and disappointment! So I've shaved it down to fit. I believe a board 13 pads wide will fit in a 1590A. The only compromise it that the connection for Depth pot lug 3  has moved from the edge of the board to, err, elsewhere. If anyone wants to etch one for me..........

[Pigyboy]

Wow. Great work Rick.
Has any one tried this with a bass yet?
My friend Dan McNay is playing with Ronnie Montrose and The Frank Hannon Band and asked me yesterday of an interesting bass chorus. Any cap replacements to make it more bass friendly would be great.
Rick, do you mind if I use the layout to make him one?  I will get pictures for you.
Thanks

[Pigyboy]

[/quote]
If anyone wants to etch one for me..........
[/quote]

I can etch a few of these and send you one next week no problem.

[frequencycentral]

Has any one tried this with a bass yet?

Earthscum has used it with bass and seems to like it!

Rick, do you mind if I use the layout to make him one?  I will get pictures for you.

That's what it's here for!

I can etch a few of these and send you one next week no problem.

I just tweaked that layout slightly so C8, C9 and C10 can be bent over to lay flat if need be, it will show up in my post above when photobucket gets it's shit together to finally refresh.

[Govmnt_Lacky]

This may be a noob question but...

If I copy the layout from Frequency above, are there any special changes I need to make in order to "size it right?" Or, is it already properly sized to populate with components?

[frequencycentral]

This may be a noob question but...

If I copy the layout from Frequency above, are there any special changes I need to make in order to "size it right?" Or, is it already properly sized to populate with components?

Scale the PnP to a .1 inch grid in photoshop. An ICs pin spacing will match the grid when correctly sized. Is that what you mean?

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I see my 'slightly tweaked' 1590A layout in my last post still hasn't refreshed in photoshop, so here's direct links in dropbox:

http://dl.dropbox.com/u/967492/LAC%201590A%20PCB.gif

http://dl.dropbox.com/u/967492/LAC%201590A%20PnP.gif

[culturejam]

Here's a little layout note:

C11 is really close to D1 (which must be mounted vertically) and R19. So it either needs to be a smallish cap, or leave some slack on the leads so you can bend it over and lay it flat over R19.

[frequencycentral]

Yeah, there's not much room there (sorry!), I didn't want to make the layout bigger just for the sake of one pesky diode. I figured people might instead mount the diode on the copper side or even directly to the DC socket. This would also allow C11 to be bent over on it's side for extra 1590A squeezage. That's what I'll gonna do.

[culturejam]

By the way, Rick, I've played around with several values of resistors where the two 220Ks are located. I ran out of 220K, so I took the opportunity to socket those spots and test it out. I can say for sure that any value between 150K and 275K will work in either or both of those positions. Waveform and min/max speed will change, of course, but several alternative values will work in a pinch.

Also, different op amps make a subtle, but noticeable, change in the LFO waveform shape.

[Govmnt_Lacky]

Scale the PnP to a .1 inch grid in photoshop. An ICs pin spacing will match the grid when correctly sized. Is that what you mean?

I do not have Photoshop. Any other way to ensure it prints out to correct size?

[nordine]

Scale the PnP to a .1 inch grid in photoshop. An ICs pin spacing will match the grid when correctly sized. Is that what you mean?

I do not have Photoshop. Any other way to ensure it prints out to correct size?

the hard way: trial and error 

i print three tries with marginally different sizes, then pick an IC socket and see on which one it fits better

[frequencycentral]

Scale the PnP to a .1 inch grid in photoshop. An ICs pin spacing will match the grid when correctly sized. Is that what you mean?

I do not have Photoshop. Any other way to ensure it prints out to correct size?

You can also do it in MS Publisher, I just tested it. I made a grid 0.254mm (= 0.1") and scaled the pad spacings to that. Worked a treat.

[Govmnt_Lacky]

Scale the PnP to a .1 inch grid in photoshop. An ICs pin spacing will match the grid when correctly sized. Is that what you mean?

I do not have Photoshop. Any other way to ensure it prints out to correct size?

You can also do it in MS Publisher, I just tested it. I made a grid 0.254mm (= 0.1") and scaled the pad spacings to that. Worked a treat.

I also do not have MS Publisher. As you can tell from my login, I work for the government. They do not give us cool software tools like MS Publisher. Any other ideas? Sorry to be a pain. Can anyone tell me a % to shrink this down to in order to get the sizes correct?
Any other ideas would be appreciated.

[Govmnt_Lacky]

You can also do it in MS Publisher, I just tested it. I made a grid 0.254mm (= 0.1") and scaled the pad spacings to that. Worked a treat.

Sorry about my first reply.... Here goes again...

I also do not have MS Publisher. As you can tell from my login, I work for the government. They do not give us cool software tools like MS Publisher. Any other ideas? Sorry to be a pain. Can anyone tell me a % to shrink this down to in order to get the sizes correct?
Any other ideas would be appreciated.

[radio]

Hi

I m at work too(but in Central Europe). I just "open with" PAINT , did a "resize" to 50%.

I printed out and mesured,seems to be ok with 2.54 mm distance from hole to hole.

Regards Jean-Marie