Chunk Systems - Agent 00FUNK!

pedalgrinder · Post by **pedalgrinder** » 10 Jul 2012, 06:41

I will pray to the pedal gods most profusely for you!!! May your solder flow well and behold a pedal for before you! Now go young jedi use the pedal force.

Bernardduur · Post by **Bernardduur** » 11 Jul 2012, 06:22

hellinoo wrote:Ok I have a schematic written on paper. I used the original schematic and traced the unit only with the pictures provided. The original schematic appears to be correct. Except for small changes in the values of resistors (I'm not sure because of the bad quality pictures). Especialy R4,R10,R6,R9. I've might have missed something so I'm going to double chceck it. I'm also using schematics of other effects as some sort of guidline. When I'll tripple chceck the schematic, I'm gonna try it on a testboard. If it works I'll build it and post vertified schematics and layouts here (+ some optional mods of mine that came to my mind today). Wish me luck. I'm gonna need it.

I also found these two pictures. Helped me a lot.
FRONT
BACK

Nice! It is a shame I don't have the pedal anymore (I had it for a test so only limited time)........

chicago_mike · Post by **chicago_mike** » 07 Jun 2014, 02:49

Did I post these already???

chicago_mike · Post by **chicago_mike** » 08 Jun 2014, 01:35

Anybody brave enough to try a layout?

Nocentelli · Post by **Nocentelli** » 08 Jun 2014, 07:00

MkI or mk2?

chicago_mike · Post by **chicago_mike** » 08 Jun 2014, 08:04

either or

lietuvis · Post by **lietuvis** » 08 Jun 2014, 08:42

chicago_mike wrote:Anybody brave enough to try a layout?

definitely, will try, to fit 1590b, fairly simple circuit as well as brown dog, could be both in same enclosure.

chicago_mike · Post by **chicago_mike** » 08 Jun 2014, 08:56

Both in one enclosure would be cool. Make the "side chain" thing a footswitch option.

Nocentelli · Post by **Nocentelli** » 11 Jun 2014, 18:41

I'm going to breadboard this tonight, but i have no 3v zeners. I have other values, maybe 5v1. I've seen plenty of OTA filters of this type, but i've not come across this variation with what looks like a bias voltage applied to pin 1+16, so i'm not sure if it could be kludged with a straight voltage divider, say 6k8 instead of the zener?

chicago_mike · Post by **chicago_mike** » 12 Jun 2014, 13:17

Its a real nice sounding filter pedal.

Nocentelli · Post by **Nocentelli** » 12 Jun 2014, 14:04

Demo's sound good, but they're all with bass: I'm building this for guitar but i do like a nice resonant LPF sweeping the low frequencies, so i'm sure it will work ok. If it works out on the breadboard, i'll do a vero layout, probably replacing the trigger input with a send/return loop like the Meatball. Thanks again for the schematics.

chicago_mike · Post by **chicago_mike** » 12 Jun 2014, 14:57

Happy to help!

karul · Post by **karul** » 01 Jul 2014, 11:01

There are few minor errors in Bernard d'Uur's schematic for Mark II (thanks to chicago_mike):

R24 is 100k - should be 220k

(part number errors)
R29 should be R25
R30 should be R7
C81 should be C9
P1 should be P4 - squelch pot

version 1.01

johnk · Post by **johnk** » 19 Sep 2014, 20:06

I used Bernard's schematic and added the chip's pinout numbers so I could more easily draw up a PCB with diy layout creator.
I then etched a PCB for it, and built it but it's not working yet. I've tested it and scoped pretty extensively, it but something is definitely not right.
here's his schemo with the chip #'s:

and here's my layout:

if anyone can see any errors on the schemo or my layout and help me with this, it will be greatly appreciated, since i'd like to pair this envelope pedal with the Brown Dog that I recently built.

chicago_mike · Post by **chicago_mike** » 19 Sep 2014, 21:22

chicago_mike · Post by **chicago_mike** » 19 Sep 2014, 21:23

John, do you have the origional factory schematic and other files?

johnk · Post by **johnk** » 19 Sep 2014, 22:11

the ones that you posted? if so, yes.
I guess that i'll try drawing up a new PCB for it.

karul · Post by **karul** » 20 Sep 2014, 00:29

I've breadboard it few months ago - it didn't work. I didn't have much time for double checking and troubleshooting, it's temporarily abandoned.

johnk · Post by **johnk** » 20 Sep 2014, 00:42

I scoped mine and tried a bunch of stuff but to no avail.
Bernard's schematic shows pins 3, 5 & 10 on the TL074 going to vref, as well as pin 5 on the LM324N, whereas Mike's shows all of those pins going to ground so the power supply is wired differently in the two posted schematics.

karul · Post by **karul** » 20 Sep 2014, 00:59

johnk wrote:I scoped mine and tried a bunch of stuff but to no avail.
Bernard's schematic shows pins 3, 5 & 10 on the TL074 going to vref, as well as pin 5 on the LM324N, whereas Mike's shows all of those pins going to ground so the power supply is wired differently in the two posted schematics.

they are the same, take a better look at the power section of Mike's schematic:

GND is marked as V-, and virtual ground as GND

Chunk Systems - Agent 00FUNK! [traced]