# MS20 Filter on Stripboard LED question **URL:** \ **Category:** DIY STUFF\ **Created:** [June 19, 2020, 9:08am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261 "2020-06-19T09:08:43Z")\ **Posts on this page:** 19\ **Page:** 2
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [June 19, 2020, 11:53am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/21 "2020-06-19T11:53:42Z")
this line ![LPF - MS20+filter+stripboard+layout grossi](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/c/c9d9a87cf49911961a6c32e6abbaea6b54972e38.jpeg) ---
**Author:** ![THOGRE](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/thogre/32/5189_2.png) [@THOGRE](https://lookmumnocomputer.discourse.group/u/THOGRE)\ **Post date:** [June 19, 2020, 11:57am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/22 "2020-06-19T11:57:04Z")
Yes, you are right ☹ now i got it ☹ ☹ ---
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [June 19, 2020, 12:04pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/23 "2020-06-19T12:04:26Z")
another thing that I always do to avoid shifting things, I trace the +12 with red felt pen across the entire line of the stripboard, same in black for the GND and in blue for the -12 ![s-l300](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/d/d8be6c325a1a15015966b8182ac3297e3e84ec29.jpeg) ---
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [June 19, 2020, 3:48pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/24 "2020-06-19T15:48:50Z")
> [@Annotated Simple Low Pass Filter Stripboard](https://lookmumnocomputer.discourse.group/t/annotated-simple-low-pass-filter-stripboard/1266): > > I did some scribbles on top of [the LMNC low pass stripboard layout](https://www.lookmumnocomputer.com/projects#/simple-filter), showing what’s inside the chips, where the power rails are, what voltages to expect on the supply pins, etc. Posting it as new topic to make it easier to link to it slight_smile See [here](https://lookmumnocomputer.discourse.group/t/annotated-simple-1v-oct-oscillator-stripboard/1267) for the annotated Simple 1V/Oct Oscillator stripboard. ---
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [June 19, 2020, 3:56pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/25 "2020-06-19T15:56:14Z")
> [@THOGRE](#): > > Where can I see which voltage has to be where? Looks like @Dud has already identified the issues, but I posted an annotated stripboard here, with the supply lines and voltages marked out: > [@Annotated Simple Low Pass Filter Stripboard](https://lookmumnocomputer.discourse.group/t/annotated-simple-low-pass-filter-stripboard/1266): > > I did some scribbles on top of [the LMNC low pass stripboard layout](https://www.lookmumnocomputer.com/projects#/simple-filter), showing what’s inside the chips, where the power rails are, what voltages to expect on the supply pins, etc. Posting it as new topic to make it easier to link to it slight_smile See [here](https://lookmumnocomputer.discourse.group/t/annotated-simple-1v-oct-oscillator-stripboard/1267) for the annotated Simple 1V/Oct Oscillator stripboard. (measure the voltages from ground to the pin, and make sure you have both the right voltages and the right polarity) To find the supply pins more generally, use google to find the datasheet, locate the right pinout, and look for pins named VCC, VEE, or similar. For example, the TL074 datasheet is [here](https://www.ti.com/product/TL074) and it has the following drawing: ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/8/8c8764e7899d8d8487e4fa6769d8f62001a7278c.png) Note the pins named VCC+ and VCC−; they’re the positive and the negative supply for this package. The negative supply is sometimes named VEE or VSS, and the positive supply can also have multiple names, and sometimes the chip wants a GND too; you may have to look at the pin descriptions to figure out what’s what. If you stumble upon some datasheet where it’s not clear, the people on this forum can help. ---
**Author:** ![THOGRE](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/thogre/32/5189_2.png) [@THOGRE](https://lookmumnocomputer.discourse.group/u/THOGRE)\ **Post date:** [June 19, 2020, 4:32pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/26 "2020-06-19T16:32:27Z")
First Thx a lot, now I have some kind of filterng BUT the Diodes are alsways clipping I guess I have to change the Input resistor, right? And if I unplug everything except the Output of the filter it sounds and beaves like an oscillator ?!?? @Dud I´ve looked over my PCB and the Schematic and i´ve don´t forgot a row. Just the Cable were @ the wrong place and one Cable from the cutoff pot. Checked also the cable at the switch and there okay too… ---
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [June 19, 2020, 4:48pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/27 "2020-06-19T16:48:14Z")
> [@THOGRE](#): > > And if I unplug everything except the Output of the filter it sounds and beaves like an oscillator ?!?? With a lot of resonance a VCF can enter in auto oscillation, like a VCO, it’s normal, try to put the resonance pot to zero for the line, maybe i don’t see very well on your pic, and so much the better that i’m wrong it’s not the whole circuit to be redone 😉 ---
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [June 19, 2020, 5:01pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/28 "2020-06-19T17:01:59Z")
i check again and if you look on schem (5 line between the 2 IC) and not a power wire to the line 5 ![LPF - MS20+filter+stripboard+layout grossi](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/c/ca075f4f9599b7a78effc05206d8c5e4e40284c6.jpeg) ![Sans titre](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/0/0e6df3dc9c8638653d426dc03b2d251beee57bd4.jpeg) the white wire is not good, but also the blue one ---
**Author:** ![THOGRE](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/thogre/32/5189_2.png) [@THOGRE](https://lookmumnocomputer.discourse.group/u/THOGRE)\ **Post date:** [June 19, 2020, 5:07pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/29 "2020-06-19T17:07:53Z")
Yes, i know, ive changed it like on the first pic. Red +12 on 4 Blue GND on 3 White -12 on 2 Thats the right way, or i am blind and check nothing 🙂 ---
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [June 19, 2020, 5:10pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/30 "2020-06-19T17:10:53Z")
ok so with less resonance it will be working ! ---
**Author:** ![THOGRE](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/thogre/32/5189_2.png) [@THOGRE](https://lookmumnocomputer.discourse.group/u/THOGRE)\ **Post date:** [June 19, 2020, 5:12pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/31 "2020-06-19T17:12:15Z")
I hope so, first i try to change the resistor on the input maybe it helps. ---
**Author:** ![troberts289](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/troberts289/32/735_2.png) [@troberts289](https://lookmumnocomputer.discourse.group/u/troberts289)\ **Post date:** [May 21, 2021, 1:21am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/32 "2021-05-21T01:21:07Z")
Here’s another MS-20 question… I’ve seen schematics like the Barton BMC55 call for 6 clipping diodes, but this stripboard and a lot of other kits only call for 2 LEDs. What’s the difference between using 2 Vs 6 diodes? I figure Korg wouldn’t use 4 extra diodes if they didn’t have to. I’m waiting for some parts to put my filter together, but I was planning to bread board it both ways and see. Has anyone else done that comparison? ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/0/06849a395f71cdf75fb90fb1fe04d2b43abee0d6.png) ---
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [May 21, 2021, 2:26am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/33 "2021-05-21T02:26:07Z")
Each diode has a 0.7 V drop. Putting three of them in series gives you a 2.1 V drop that needs to be overcome before that feedback path opens. This is similar to the voltage drop of a (old style, low intensity) green LED. ---
**Author:** ![troberts289](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/troberts289/32/735_2.png) [@troberts289](https://lookmumnocomputer.discourse.group/u/troberts289)\ **Post date:** [May 21, 2021, 2:50am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/34 "2021-05-21T02:50:56Z")
I see, that makes sense. ---
**Author:** ![WarmwoodAudio](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/warmwoodaudio/32/25652_2.png) [@WarmwoodAudio](https://lookmumnocomputer.discourse.group/u/WarmwoodAudio)\ **Post date:** [March 26, 2023, 11:04pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/35 "2023-03-26T23:04:03Z")
Hello, super basic question here about the jacks. Should I use all 1/4" sockets, or does the cv need to be eurorack? I make guitar pedals but have been asked to make this for someone. He uses a lot of 1/4" stuff like guitar pedals with his synths, so if I can make them all 1/4" I would prefer it. Thanks! ---
**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:** [March 27, 2023, 12:28am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/36 "2023-03-27T00:28:43Z")
The jacks don’t care what the CV voltage is. It does use the same control voltage levels as Eurorack but there is no necessity for the jacks to be 3.5 mm. 1/4" is fine. But you maybe should check with your client to find out what equipment they plan to plug into it and what kind of jack they would prefer. Is it a Eurorack or Eurorack compatible (e.g. Kosmo) synth? ---
**Author:** ![WarmwoodAudio](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/warmwoodaudio/32/25652_2.png) [@WarmwoodAudio](https://lookmumnocomputer.discourse.group/u/WarmwoodAudio)\ **Post date:** [March 27, 2023, 1:59am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/37 "2023-03-27T01:59:20Z")
Thank you so much for the quick response! That seemed like the obvious answer to me but I didn’t want to make any assumptions. Sent the client an email asking what his preference is. Will post the build when it’s complete, this thread has been immensely helpful. ---
**Author:** ![K.ostas](https://avatars.discourse-cdn.com/v4/letter/k/ed655f/32.png) [@K.ostas](https://lookmumnocomputer.discourse.group/u/K.ostas)\ **Post date:** [March 28, 2023, 1:54am UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/38 "2023-03-28T01:54:40Z")
The larger voltage drop also means less clipping and compression. The difference in sound should be very noticeable in a filter circuit. ---
**Author:** ![WarmwoodAudio](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/warmwoodaudio/32/25652_2.png) [@WarmwoodAudio](https://lookmumnocomputer.discourse.group/u/WarmwoodAudio)\ **Post date:** [March 28, 2023, 6:14pm UTC](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261/39 "2023-03-28T18:14:40Z")
That’s a great point I can take down the road with me, thanks. I felt pretty dumb when asked about all this by the client. My engineering schooling was robotics club as a kid, guitar pedals were self taught and just for fun and for friends, so I’m just an ignoramus who can solder and follow directions. Learning now though because it’s fun! [Previous page](https://lookmumnocomputer.discourse.group/t/ms20-filter-on-stripboard-led-question/1261.md?page=1)