# Envelope Follower with high pass filter (ARP 2600 ) **URL:** \ **Category:** DIY STUFF\ **Created:** [June 11, 2020, 8:56am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182 "2020-06-11T08:56:32Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 11, 2020, 8:56am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/1 "2020-06-11T08:56:32Z")
Hi everyone! So i want to build Eddy Bergmanns ARP2600 Envelope follower on stripboard but I want to add an adjustable high pass filter to the input. Here is the stripboard: ![grafik](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/3/3a771b3721d5ae0057d13eb78895c591301d761d.jpeg) Where would you add that high pass filter? I was thinking adding it after the Preamp input / Bypassed input switch. A 100nF cap and a 100k pot with 100R resistor in series, would that work? How would you incorporate that? cheers ---
**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 11, 2020, 10:20am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/2 "2020-06-11T10:20:07Z")
you speak about RC filter, Sam put it on the output of this for example but like he said on the schem it’s more Tone that a filter ![SIMPLE+OSCILLATOR+AND+FILTER](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/4/4c63f7c107b5190d61fc5bf0830e04b5e0b0fa3e.jpeg) [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/6/6e01fa93ef7124a00de352732f205bebd1c70960.jpeg "FILTERS? Build a simple DIY passive electronic low pass filter. #Electronics #Synth") ](https://www.youtube.com/watch?v=Ch9w5JtbZSc) but it’s a low pass not hi, and i think that a real filter would be better like this simple one (with hi pass) ![MS20HPFLPFixed](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/d/d3fcbc4b0924e761271b83764d1f23eb001fce37.jpeg) ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 11, 2020, 10:44am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/3 "2020-06-11T10:44:28Z")
thanks. i just need a simple high pass, without resonance. just one knob to control the frequency. i want it in the envelope follower, because i like putting drum machines into envelope followers and then taking the generated envelope into the pitch of an oscillator. so basically the drum machine generates a melody. if you add a high pass filter before the envelope out, you can control the melody in a strange way. i do it with my ms20 mini a lot: [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/6/6e84c56ceb2302f9d830d621c73b3d88fc01acec.jpeg "OP-Z meets MS-20") ](https://www.youtube.com/watch?v=Ox6DHNpaQ_Y) at 0:34 i turn up the high pass filter of the ms20s envelope follower the first time. the patch was opz into the external signal processor and then the generated envelope cv routed to oscillator 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 11, 2020, 11:01am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/4 "2020-06-11T11:01:37Z")
cool sound ! so a RC filter should do the job i find this to test the value [https://www.amplifiedparts.com/tech-articles/filter-low-pass-high-pass](https://www.amplifiedparts.com/tech-articles/filter-low-pass-high-pass) ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 12, 2020, 10:50am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/5 "2020-06-12T10:50:48Z")
work in progress ![20200612_124629](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/d/d27065b97666e29a13fc97cacaf48275c01482dd.jpeg) i added a simple high pass filter after the preamp. 1M pot with 100R resistor in series, 1nF cap in parallel. sounded good on breadboard, i hope this will work on the module, too. i also added eurorack power and moved the smooth cap to the board. now i need to go buy a B1k pot. ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 12, 2020, 6:44pm UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/6 "2020-06-12T18:44:55Z")
![20200612_204122](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/9/9a01211b144273cb14cfc83a14cee70d80fd64fb.jpeg) this is as far as it gets for now. need to wait for the panel to show up. 3 different kinds of potentiometers, i just realized 😃 ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 22, 2020, 4:39pm UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/7 "2020-06-22T16:39:12Z")
Making progress again. Now off painting that Panel ![20200622_164915](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/4/41199555321e13fb225088b8dca187d7551c79af.jpeg) ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 22, 2020, 8:11pm UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/8 "2020-06-22T20:11:39Z")
![20200622_220418](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/2/2dafb402620901bf0ac8bac2735dedf5ca188a29.jpeg) ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 23, 2020, 8:10am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/9 "2020-06-23T08:10:29Z")
Done 🙂 ![20200623_100252](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/6/6261625d304a092b6db309fdec4be118c5878b91.jpeg) ![20200623_100319](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/4/4e01c642f931fa0b4d4cba538d90130e24a305fc.jpeg) ![20200623_100309](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/b/bc328f00443ba44795fb9a7d09215c9734977fdb.jpeg) ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 23, 2020, 12:36pm UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/10 "2020-06-23T12:36:25Z")
It works! Herr is a small jam: > **[@klausklarwerk](https://www.instagram.com/p/CBxxM8rIx9p)** Audio source is a pocket operator. The envelope out controls the pitch of 3 oscillators. Also the splashback delay is on. What confuses me a little is that the line in audio is not routed to the audio output. And i think i might have wired the hpf pot backwards, but who cares 😉 ---
**Author:** ![EddyBergman](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/eddybergman/32/13513_2.png) [@EddyBergman](https://lookmumnocomputer.discourse.group/u/EddyBergman)\ **Post date:** [June 30, 2020, 11:26am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/11 "2020-06-30T11:26:03Z")
Fantastic work Klaus! ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [June 30, 2020, 2:01pm UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/12 "2020-06-30T14:01:41Z")
Thanks man! I just replied to your post on ig ---
**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:** [October 29, 2020, 11:00am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/13 "2020-10-29T11:00:46Z")
Sorry but i don’t want to make some mistake, can you please make me a little drawing for the HPF pot with cap and R, and where is exactely the connection on the board thx a lot ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [October 29, 2020, 11:18am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/14 "2020-10-29T11:18:14Z")
hi, unfortunately i don’t have access to my modular for the next few weeks. but with hindsight you don’t really need that hpf, as i realized the filter does not affect the audio signal, but just the signal into the envelope follower. so it only kind of interacts with the threshhold knob (envelope follower input level knob in eddys layout) but the audio won’t be filtered which is what i hoped for. ---
**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:** [October 29, 2020, 11:41am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/15 "2020-10-29T11:41:37Z")
ok thank you ! … ---
**Author:** ![BlackDeath](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/blackdeath/32/7644_2.png) [@BlackDeath](https://lookmumnocomputer.discourse.group/u/BlackDeath)\ **Post date:** [October 29, 2020, 5:54pm UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/16 "2020-10-29T17:54:00Z")
Dang, thanks for bumping this thread, hadn’t seen it before. Very cool technique! Love the true Kosmo panel. ---
**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:** [November 5, 2020, 12:30am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/17 "2020-11-05T00:30:51Z")
Just an idea, if you add another RC HPF on the audio out, after with a double potentiometer, you can with one pot control 2 filters, on for each out (Env and Audio) A question, this module have a Mic input, an Instru input and a Line input, but no Synth input. so we can’t use it with another module with synth signal ? or it only make to create an envelope with an external source ? it’s not really clear for me … thx ---
**Author:** ![eric](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@eric](https://lookmumnocomputer.discourse.group/u/eric)\ **Post date:** [November 5, 2020, 6:31am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/18 "2020-11-05T06:31:32Z")
At the worst, a passive attenuator (@Dud I know you have a module with some) in series with the line-in and voila. ---
**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:** [November 5, 2020, 9:19am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/19 "2020-11-05T09:19:30Z")
Yes of course it’s surely the most simplest way to add it, thx @eric ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [November 5, 2020, 9:43am UTC](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182/20 "2020-11-05T09:43:36Z")
i’d just try the instrument and line inputs for synth signals. but what is the point here? the module generates envelopes out of what you run into it. so if you for example run a droning oscillator into it, the generated envelope will just have infinite sustain. if you run single notes, cut off by a vca or filter into it, the envelope will look the same as the one used to control said vca or filter. i mostly use it to generate envelopes from drummachines. i think the who used it with guitar to vca, so the synth voice would duck whenever there is something played on the guitar. [Next page](https://lookmumnocomputer.discourse.group/t/envelope-follower-with-high-pass-filter-arp-2600/1182.md?page=2)