Hey, just finished doing a layout for a MS-20 filter that I've put into a wah enclosure. Something tells me I've done the layout wrong as all I get is a massive volume cut and no cool whistly lp filter like I was hoping.
Heres the schematic I used:
(http://img.scoop.it/UB2Vdkzi-EKeKIoUfgCWCzl72eJkfbmt4t8yenImKBVvK0kTmF0xjctABnaLJIm9)
And here's my layout:
(http://i.imgur.com/rU5JK8c.png)
Is the problem with the LM13700? I was pretty sure the pinout was the same as the LM13600.
Your layout looks ok, except it doesn't show any cut traces under the LM13700, have you actually cut them? Are D1 and D2 connected together off the board, they don't connect to the 9 Volt row?
Yep they're all cut under the IC, just couldn't figure out how to show that in DIYLC. The two LED's aren't on the 9v either. I'm starting to think this may be a problem with my pots.
Quote from: Quarterflip on December 05, 2015, 09:43:33 AM
Is the problem with the LM13700? I was pretty sure the pinout was the same as the LM13600.
The pinout is the same, but are you sure that circuit works with the 13700? The only difference between the 13600 and the 13700 is in the buffers and the way they are biased. I often leave the darlingtons unused anyway, so it doesn't make any odds. But in this schematic, the buffers are used, so...
Dunno, it's just a thought.
HTH,
Tom
Oh, and you haven't shown the cut at the midpoint of D1-D2 either. That needs to be there.
Quote from: Quarterflip on December 05, 2015, 10:37:23 AM
Yep they're all cut under the IC, just couldn't figure out how to show that in DIYLC.
Double click on the part, and in the pop up, move the "Alpha" slider to the left. This will increase the transparency of the part.
So I added the cuts under the IC and LED's
(http://i.imgur.com/mPH0rJl.png)
Would the darlington's bias make that big of a difference?
Quote from: Quarterflip on December 05, 2015, 10:26:14 PM
Would the darlington's bias make that big of a difference?
I don't know, but it might. There's another thread about it here:
http://www.diystompboxes.com/smfforum/index.php?topic=85279.0 (http://www.diystompboxes.com/smfforum/index.php?topic=85279.0)
Some of these comments imply that people built working filters with the 13700, so I'd guess it works. A simple wiring error is still more likely.
HTH,
Tom
shift the cut under the leds left 1. shift the bottom led right 1. anchor both ends of both leds to the board.
did anyone get this to work????
You might be interested in comparing this circuit to the schematic and (more complex) vero layout for an MS-20 filter using two LM13700, in the forum section of the tagboardeffects.blogspot.com blog. See http://guitar-fx-layouts.42897.x6.nabble.com/Korg-MS20-LP-HP-Filter-tp31433.html (http://guitar-fx-layouts.42897.x6.nabble.com/Korg-MS20-LP-HP-Filter-tp31433.html) Note that is intended to run off +/- 15V.
I know this is an old thread, but I've succesfully build this with the layout above. Just make sure that the led junction does not connect to the 9v ic pin. I've used the 13700 chip and two 5mm red leds. Ive made a version before with 5mm yellow leds but that drastically changes the sound and resonance. Heres a video impression.
Hey, this might be a dumb question, but I´m a beginner. What does Vr mean?
Thanks!
Welcome to the forum.... :icon_wink:
Vr normally means "Reference voltage" which normally is about 1/2 the power supply... :icon_wink:
Don't think the question is dumb, we all were there before... :icon_wink: