# Schmitzbits 555 ADSR problem **URL:** \ **Category:** DIY STUFF\ **Created:** [January 16, 2021, 5:53pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705 "2021-01-16T17:53:14Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![lu.caas](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lu.caas/32/12420_2.png) [@lu.caas](https://lookmumnocomputer.discourse.group/u/lu.caas)\ **Post date:** [January 16, 2021, 5:53pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/1 "2021-01-16T17:53:14Z")
Hi everyone I’m really pissed off, I spent 3 hours trying to made this (image below) ADSR from Schmitbitz but it doesn’t work correctly. Even through I checked every components every connections the resistances of every resistors and all but no it doesn’t want to work correctly… The problem is that when I put the decay at maximum the ADSR level goes to 11V without being triggered, and when I trigger it, it only goes to 5V or 4V. Maybe I should change the value of some components? I don’t know… Maybe I should power the opamp with +12V and -12V? ![adsr2 (1)](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/3/37618e0e41e9451606dfabc7b8f3d67c9eba3531.png) Thank if you can help and thanks for your attention ---
**Author:** ![Caustic](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/caustic/32/15588_2.png) [@Caustic](https://lookmumnocomputer.discourse.group/u/Caustic)\ **Post date:** [January 16, 2021, 8:00pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/2 "2021-01-16T20:00:50Z")
Check cap or resistor values? Maybe you misread them? Got a pic? 🙂 Including pinout and construction of the 555 to help troubleshoot in the thread. ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/1/1dba9943398c11d404d2af542d9e07eab8b84f48.png) ---
**Author:** ![lu.caas](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lu.caas/32/12420_2.png) [@lu.caas](https://lookmumnocomputer.discourse.group/u/lu.caas)\ **Post date:** [January 16, 2021, 8:17pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/3 "2021-01-16T20:17:58Z")
Yeah I already checked that with my multimeter if my soldering were good and it was, verified every resistors, checked the schematic I made on KiCAD… Aaah omg I think maybe my 555 is bad, I mean it’s weird. Thanks dude but I think I’m doomed Here’s a messy pic of my build and just showed the part that doesn’t work [20210116\_211550|690x317](https://lookmumnocomputer.discourse.group/uploads/short-url/iJnGJLDsDAnFytlYJerx9vg2r0d.jpeg) ---
**Author:** ![Caustic](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/caustic/32/15588_2.png) [@Caustic](https://lookmumnocomputer.discourse.group/u/Caustic)\ **Post date:** [January 16, 2021, 8:18pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/4 "2021-01-16T20:18:21Z")
Double check the polarity of your diodes. So your issue is with the decay at max makes the level go to 11v untriggered, and when triggered it drops voltage to 4-5v. If i am reading this right, the 2.2M decay pot is connected in series with the 12k sustain pot. That is connected to the discharge pin, which simply routes through a transistor to ground. Since you get a voltage drop when you turn up your decay, this means that increasing the resistance there is causing the voltage drop before the inverting OpAmp stage. I could be wrong, but if the diode connected to decay were inverted, i think this might explain why. ---
**Author:** ![lu.caas](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lu.caas/32/12420_2.png) [@lu.caas](https://lookmumnocomputer.discourse.group/u/lu.caas)\ **Post date:** [January 16, 2021, 8:22pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/5 "2021-01-16T20:22:39Z")
Ooh wait I’m gonna check that (even through I checked many time but I’m silly haha) thanks again to trying to understand 😅 ---
**Author:** ![Caustic](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/caustic/32/15588_2.png) [@Caustic](https://lookmumnocomputer.discourse.group/u/Caustic)\ **Post date:** [January 16, 2021, 8:25pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/6 "2021-01-16T20:25:29Z")
I posted that before i saw the image. the polarity looks fine. Right now, i would check the connection to the board below as well as the pots themselves. Make sure everything is grounded. ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/d/d4692c0d39e354f82a64e71e2f198d19af37a47d.jpeg) ---
**Author:** ![lu.caas](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lu.caas/32/12420_2.png) [@lu.caas](https://lookmumnocomputer.discourse.group/u/lu.caas)\ **Post date:** [January 16, 2021, 8:30pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/7 "2021-01-16T20:30:30Z")
Yeah the pots are connected to the board and their values are fine, my soldering looks sketchy but the wires are soldered don’t worry. I also didn’t connect the center pin since we just use two wires on the pots except for the sustain. ![SmartSelect_20210116-212949_Samsung Notes](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/d/d1fc75bd4565cdb37a7bdc797446139113bd342b.jpeg) ---
**Author:** ![lu.caas](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lu.caas/32/12420_2.png) [@lu.caas](https://lookmumnocomputer.discourse.group/u/lu.caas)\ **Post date:** [January 17, 2021, 4:01pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/8 "2021-01-17T16:01:24Z")
My meter was broken… My 60€ meter was broken? When I set my supply to 12V it shows 8V and when I set my supply to 8V it shows 5V… So my adsr kinda works now. The only problem is that if I set the decay at maximum (or minimum i don’t know) it sets the output of the opamp at 12V. Plus the voltage of the ADSR drops even when I set the sustain at maximum For example I set the sustain on its maximum level here so the voltage should stay linear but it’s dropping ![Screenshot_20210117-170023_Gallery](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/7/788e6447a5fdb381bdf83f6952eeadba15cae144.jpeg) ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [January 18, 2021, 2:42am UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/9 "2021-01-18T02:42:44Z")
Where’s the PCB from? ---
**Author:** ![lu.caas](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lu.caas/32/12420_2.png) [@lu.caas](https://lookmumnocomputer.discourse.group/u/lu.caas)\ **Post date:** [January 18, 2021, 5:43am UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/10 "2021-01-18T05:43:20Z")
It’s from JLCPCB . I made it on KiCAD ---
**Author:** ![lu.caas](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lu.caas/32/12420_2.png) [@lu.caas](https://lookmumnocomputer.discourse.group/u/lu.caas)\ **Post date:** [January 22, 2021, 4:51pm UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/11 "2021-01-22T16:51:08Z")
I’m so dump omg… My probe were discharging the cap and the opamps needed 24V… ---
**Author:** ![Shiro\_pb](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/shiro_pb/32/8576_2.png) [@Shiro\_pb](https://lookmumnocomputer.discourse.group/u/Shiro_pb)\ **Post date:** [December 30, 2022, 12:30am UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/12 "2022-12-30T00:30:55Z")
Hello folks. i’m reviving this post because i’m dealing with the same circuit but i have a different problem. i don’t have access to a scope so i’ll describe the workings of my ADSR after listening to it A is adding a delay to the beginning of the sound from the positive edge of the gate D is adding a volume slope to the attack of the sound (what i expected the A to do) S is changing the sustain level, the peak volume and the release time R does nothing There’s a loud click sound at the positive edge of the gate And sometimes it happens on the negative edge Also there’s always a residual volume after the negative edge Even with the release at minimum I’ll post the schematic as well. and the board ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/0/a/0adca706397a804ac9a99d9487caf33acd5ff4d0.png) ---
**Author:** ![Shiro\_pb](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/shiro_pb/32/8576_2.png) [@Shiro\_pb](https://lookmumnocomputer.discourse.group/u/Shiro_pb)\ **Post date:** [December 30, 2022, 12:31am UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/13 "2022-12-30T00:31:33Z")
this is the board ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/6/a/6a3107ff5c5a52528b8f3a5fa35ee2242b03c4ce.jpeg) ---
**Author:** ![Shiro\_pb](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/shiro_pb/32/8576_2.png) [@Shiro\_pb](https://lookmumnocomputer.discourse.group/u/Shiro_pb)\ **Post date:** [December 30, 2022, 12:32am UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/14 "2022-12-30T00:32:09Z")
This is the setup ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/3/f/3fb0349195833fa562db1493e785b12813fa1966.jpeg) Any help appreciated ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [December 30, 2022, 12:58am UTC](https://lookmumnocomputer.discourse.group/t/schmitzbits-555-adsr-problem/2705/15 "2022-12-30T00:58:36Z")
I don’t see any discrepancies between your schematic and Schmitz’s, at least for the ADSR part. I do see you’re using an NE555P. This isn’t quite equivalent to the ICM7555. I recommend trying the latter, see if that improves performance. If not then presumably there’s some error in the PCB layout or assembly. > [@Shiro\_pb](#): > > Also there’s always a residual volume after the negative edge Even with the release at minimum This is presumably the known behavior that’s been discussed here before, a characteristic of this circuit and similar ones. Basically the problem is that the release voltage can’t get to 0 V other than very slowly once it’s dropped low enough compared to the diode forward voltage. There’s a design from Kassutronics that mostly avoids the problem by using op amps with the diodes to make precision rectifiers: > **[Precision ADSR](https://kassu2000.blogspot.com/2015/05/precision-adsr.html)** > > This is a modified version of Yves Usson's Yusynth ADSR envelope generator , which is in turn based on an 1980  article  by Jonathan Jacky ... (there’s still a small amount of offset left due to transistor resistance, and there’s at least one design that supposedly fixes that by using MOSFETs, but it’s a much smaller problem.) I did a Kosmo version of the Kassutronics ADSR and it works well.