# Music Thing Spring Reverb **URL:** \ **Category:** KOSMO MODULES\ **Created:** [May 6, 2023, 12:31am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164 "2023-05-06T00:31:30Z")\ **Posts on this page:** 15\ **Page:** 1
**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:** [May 6, 2023, 12:31am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/1 "2023-05-06T00:31:30Z")
I took a look at Sam’s spring reverb module when it came out, but decided I wanted something less crunchy. So I did this Kosmo adaptation of the Music Thing Modular driver (Mk II). ![PXL_20230505_234235219](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/2/0/201678f42781ea61d1ccf7f8007ba05654298cea.jpeg) (Once again the 3D printed front panel is a stand-in until I get an FR4 one fabbed.) There’s only few very minor circuit tweaks. As with the original it can, and in my build it does, include the Belton Accutronics “brick” as an alternative to the spring tank. It incorporates the Music Thing expansion module, which consists only of a pot to mix between tank and brick, and a pair of phono jacks on the front panel parallel to the ones on the PCB. (I didn’t bother mounting those on this temporary panel.) I’m using this with an Accutronics 4EB2C1B tank. The behavior’s VERY sensitive to the trim pot, there’s a small window between basically dead and out of control where it’s all good. Schematics, layout, Gerbers, and documentation may be found at: > **[GitHub - holmesrichards/mtmreverb: Spring and "brick" reverb driver synth module](https://github.com/holmesrichards/mtmreverb)** > > Spring and "brick" reverb driver synth module. Contribute to holmesrichards/mtmreverb development by creating an account on GitHub. ---
**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:** [May 6, 2023, 10:03am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/2 "2023-05-06T10:03:48Z")
Nice work, can we get a sound demo? ---
**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:** [May 6, 2023, 10:44am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/3 "2023-05-06T10:44:41Z")
Haven’t recorded anything yet but since it’s the same as the Eurorack version here’s DivKid’s demo of that: [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/9/3/93ba5e60813a3c9282ccedfdd060d93d669d251e.jpeg "Music Thing Modular - Spring Reverb mkii") ](https://www.youtube.com/watch?v=dQl8YyCtgHE) ---
**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:** [May 18, 2023, 2:31pm UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/4 "2023-05-18T14:31:25Z")
I put the fabbed panel and knobs on: ![front](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/1/2/127025d7d018916ec8a7b6a25d6fc7b6c910be96.jpeg) Extra boards and panels are for sale on Tindie: > **[Spring reverb by Analog Output on Tindie](https://www.tindie.com/products/analogoutput/spring-reverb/)** > > Spring reverb driver synth module (Discovered just as I was about to put the “To” panel jack on, I’d given it a ground connection on the panel. Oops. Two nylon washers and we’re good…) ---
**Author:** ![richy486](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/richy486/32/23222_2.png) [@richy486](https://lookmumnocomputer.discourse.group/u/richy486)\ **Post date:** [August 26, 2023, 11:08am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/5 "2023-08-26T11:08:21Z")
Say if someone with the v1.0 did forget to put a nylon washer around the ‘to’ socket and they couldn’t hear any output afterwards, could that be the cause? Could a chip be fried? ---
**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:** [August 26, 2023, 11:53am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/6 "2023-08-26T11:53:48Z")
I don’t really know, but I’d guess not? More likely some other assembly problem, I’d think. ---
**Author:** ![richy486](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/richy486/32/23222_2.png) [@richy486](https://lookmumnocomputer.discourse.group/u/richy486)\ **Post date:** [September 9, 2023, 3:46am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/7 "2023-09-09T03:46:44Z")
Turns out I was missing two components, don’t know how I missed them, looked over the board 100 times ---
**Author:** ![krztoff](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/krztoff/32/29609_2.png) [@krztoff](https://lookmumnocomputer.discourse.group/u/krztoff)\ **Post date:** [October 7, 2024, 7:13pm UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/8 "2024-10-07T19:13:15Z")
I’m considering editing/widening the front panel of this so that I can mount the tank sideways and expose the springs (similar to killerdev’s module here [DIY Spring Reverb Module](https://lookmumnocomputer.discourse.group/t/diy-spring-reverb-module/4815)). Has anyone else already tackled this? ---
**Author:** ![Sussmayr](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sussmayr/32/22691_2.png) [@Sussmayr](https://lookmumnocomputer.discourse.group/u/Sussmayr)\ **Post date:** [November 10, 2024, 1:04am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/9 "2024-11-10T01:04:35Z")
Rich, I finally built out the MT Spring Reverb I bought from you a while back. Everything was fine except I couldn’t get any audio out of the brick. Checking all my work, checking damned near everything in my rabbit-hole state of mind until finally, under the scrutiny of a loop magnifier, I see that SJ-101 is closed to ground in the copper mask. I assumed that S-101 was open because… well assumptions do get us in trouble. I opened SJ101 and all is well in Spring Land and I have another brick in the wall. This is a really cool spooky unit. The MOD 8EB2C1B tank is a beautiful thing with it. ---
**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:** [November 10, 2024, 1:32am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/10 "2024-11-10T01:32:10Z")
Yeah, that’s mentioned in the README but I guess it’s easy to overlook: > Errata > > - In the v1.0 circuit boards the solder jumper is bridged, not open, so it should be cut if using the brick and left alone if not (contrary to what the silkscreen implies). ---
**Author:** ![Sussmayr](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sussmayr/32/22691_2.png) [@Sussmayr](https://lookmumnocomputer.discourse.group/u/Sussmayr)\ **Post date:** [November 10, 2024, 3:23am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/11 "2024-11-10T03:23:54Z")
Good thing the rest of the world is passed v1.0 then! For me it was the thrill of the chase. ---
**Author:** ![Sussmayr](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sussmayr/32/22691_2.png) [@Sussmayr](https://lookmumnocomputer.discourse.group/u/Sussmayr)\ **Post date:** [November 10, 2024, 3:31pm UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/12 "2024-11-10T15:31:46Z")
Hmmmm … I did not have the Readme.md so I was working underinformed. All my old links send me to your old Github repository that has moved to GitLab. I’m all caught up now after an extended absence. The Reverb design is a ton of fun to use especially with some external CV modulation. ---
**Author:** ![krztoff](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/krztoff/32/29609_2.png) [@krztoff](https://lookmumnocomputer.discourse.group/u/krztoff)\ **Post date:** [February 4, 2026, 1:46am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/13 "2026-02-04T01:46:49Z")
I can’t get this thing calibrated to save my life. The trimmer does nothing at all for me. If I tap the spring (the exact same spring mentioned in the OP) I can barely hear it through my speakers, but mostly it’s just overly hummy and unusable. The brick works great fortunately and has none of the hum issues either. ---
**Author:** ![Farabide](https://avatars.discourse-cdn.com/v4/letter/f/ecc23a/32.png) [@Farabide](https://lookmumnocomputer.discourse.group/u/Farabide)\ **Post date:** [February 4, 2026, 6:06pm UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/14 "2026-02-04T18:06:34Z")
I have had a similar situation with the reverb tank in a combo amp. Check your grounding. The wires used in the tank are fragile and can separate from the phono sockets and the driver. ---
**Author:** ![krztoff](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/krztoff/32/29609_2.png) [@krztoff](https://lookmumnocomputer.discourse.group/u/krztoff)\ **Post date:** [February 5, 2026, 3:31am UTC](https://lookmumnocomputer.discourse.group/t/music-thing-spring-reverb/6164/15 "2026-02-05T03:31:08Z")
I have pretty low confidence in the vactrol actually. I think my next tests will be focused on that. The hum I think is just due to location near the psu.