# Schmitz White Noise Generator **URL:** \ **Category:** DIY STUFF\ **Created:** [March 5, 2020, 5:47pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355 "2020-03-05T17:47:47Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![sketchie](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sketchie/32/144_2.png) [@sketchie](https://lookmumnocomputer.discourse.group/u/sketchie)\ **Post date:** [March 5, 2020, 5:47pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/1 "2020-03-05T17:47:47Z")
built one of these this afternoon, it’ll be one of a few, some that will find themselves incorporated into other modules 🤪 ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/1X/252f20c838456a9ccef965365b3339727df3d4c5.png) here’s mine =\> ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/1X/ed9a5fd98e0cd5595f21281f419ee40d36a834a5.jpeg) ---
**Author:** ![sketchie](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sketchie/32/144_2.png) [@sketchie](https://lookmumnocomputer.discourse.group/u/sketchie)\ **Post date:** [March 5, 2020, 8:38pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/2 "2020-03-05T20:38:12Z")
Some images off my 'scope of the output 🤪 🕶 👍 ![100_0339](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/1X/9d58439df1aa69ce9c8989dd498bc93db2dadc87.jpeg) ![100_0340](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/1X/130fc66400029e982296e87603e12df29e112541.jpeg) ![100_0342](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/1X/832403bc86e19f8fd2747d5bbc3c862616c65dc0.jpeg) ![100_0343](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/1X/103ce2179738a9eb7cf1a643979c72d402132fbe.jpeg) ---
**Author:** ![antoine.pasde2](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/antoine.pasde2/32/326_2.png) [@antoine.pasde2](https://lookmumnocomputer.discourse.group/u/antoine.pasde2)\ **Post date:** [March 5, 2020, 8:39pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/3 "2020-03-05T20:39:41Z")
Who designed the stripboard layout from the schematic? The schematic shows a +15V source, which points to a +/-15V supply for the opamps, given the bipolar nature of the AC coupled noise source, but the stripboard shows only a +12V supply. What did you implement? Is the output signal clipped to ground on the negative side? ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [March 5, 2020, 9:37pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/4 "2020-03-05T21:37:11Z")
Good points. On the other hand it’s a noise source intended for analogue synthesis. They used to say “Good enough for jazz.” ---
**Author:** ![Maxhirez](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/maxhirez/32/42_2.png) [@Maxhirez](https://lookmumnocomputer.discourse.group/u/Maxhirez)\ **Post date:** [March 5, 2020, 11:20pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/5 "2020-03-05T23:20:46Z")
I’ve seen a couple of René Schmit’s designs and I want to say this isn’t the first where he’s used a single rail source on a 7x op amp design. (He has a lot of great schematics [here](https://www.schmitzbits.de/noise.html) BTW.) This is pretty similar to the noise source I used in the dirty snare drum I talked about (but failed to demonstrate) in another thread, and that only barely made the transistor sizzle at 12v-you really needed the 15v to get the snap. ---
**Author:** ![sketchie](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sketchie/32/144_2.png) [@sketchie](https://lookmumnocomputer.discourse.group/u/sketchie)\ **Post date:** [March 6, 2020, 9:41am UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/6 "2020-03-06T09:41:47Z")
I sourced the schematic from here =\> [https://www.reddit.com/r/synthdiy/comments/bksa1n/heres\_a\_vero\_layout\_ive\_created\_for\_a\_nice\_and/](https://www.reddit.com/r/synthdiy/comments/bksa1n/heres_a_vero_layout_ive_created_for_a_nice_and/) I used +12v from regulated power supply. I did find that if i cranked up the voltage to +15v there seemed to be a better output. The output is connected to ground by the black cable, the red cable is connected to pin 2 of the VR 100k (pot). ---
**Author:** ![sketchie](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sketchie/32/144_2.png) [@sketchie](https://lookmumnocomputer.discourse.group/u/sketchie)\ **Post date:** [March 6, 2020, 9:53am UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/7 "2020-03-06T09:53:39Z")
I just checked, and the schematic had been taken from Rene’s library 👍 It’s a great resource 👍 🕶 ---
**Author:** ![sketchie](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sketchie/32/144_2.png) [@sketchie](https://lookmumnocomputer.discourse.group/u/sketchie)\ **Post date:** [March 6, 2020, 9:56am UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/8 "2020-03-06T09:56:47Z")
I added the header so I could just use a standard (Doepfer standard) ribbon cable 😀 ---
**Author:** ![MarkKelsall](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/markkelsall/32/1261_2.png) [@MarkKelsall](https://lookmumnocomputer.discourse.group/u/MarkKelsall)\ **Post date:** [June 14, 2020, 12:56pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/9 "2020-06-14T12:56:50Z")
Your post got me thinking, I have a board out of a radar signal simulator… I think that it has a white noise generator on it, it’s got a boost circuit to output 12 volts and a couple of 555s, plus a big chip that seems to be connected to a modulator in pin on the radar unit its self. Could rig it up to a speaker and see what comes out when activated… may be a nice source of white noise? ![Radar board](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/c/ce55facb97a98fc27e751a7f96caf58543389fe5.jpeg) ![Radar board back](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/f/f8f908c9b1dc7b311f22290665b415d18a254c81.jpeg) ---
**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 14, 2020, 1:19pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/10 "2020-06-14T13:19:33Z")
The MM54C221 is [a one-shot pulse generator](https://www.onsemi.com/pub/Collateral/AN-138.pdf.pdf) so odds are it generates nice pulse trains, not any form of noise, but it seems like a fun subject for a bit of circuit bending 👍 (the MAX642 is a ~~5V~~ 12V (see below) step up switching regulator, ~~so I assume BATT is one or maybe two 1.5 cells?~~ ) ---
**Author:** ![MarkKelsall](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/markkelsall/32/1261_2.png) [@MarkKelsall](https://lookmumnocomputer.discourse.group/u/MarkKelsall)\ **Post date:** [June 14, 2020, 1:23pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/11 "2020-06-14T13:23:40Z")
The batt is a 6 volt dry cell pack… Yes, was thinking of bending the circuit, possibly got another unit coming next week with an identical board. This thing is wired up with teflon coated braided silver wire. I made a torch out of one unit, left another as a radar source, maybe the third unit can have a speaker instead of a LED cluster? Apologies for veering off the topic somewhat… ![IMG_0969](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/e/e95b185bfc2d81eedf0868c698ddd5bb2147a3d2.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 14, 2020, 1:36pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/12 "2020-06-14T13:36:45Z")
also in this thread 😉 > [@White Noise + Sample & Hold module](https://lookmumnocomputer.discourse.group/t/white-noise-sample-hold-module/1180): > > here’s mine Kosmo format of a S&H from René Schmitz (with LF398 chip) “YASH” S&H : [sample and hold] White Noise : link : [https://www.schmitzbits.de/sah.html](https://www.schmitzbits.de/sah.html) ---
**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 14, 2020, 1:39pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/13 "2020-06-14T13:39:08Z")
> [@MarkKelsall](#): > > The batt is a 6 volt dry cell pack… Ah, right – the MAX642 is 12 V, not 5 (looked at the wrong row). Datasheet says the regulator won’t regulate if you get within a diode drop of the target output, but 6V is plenty of margin 🙂 (but you may be able to power it with 12 V if you add a couple of 1N400x diodes in series on the way in) I have no idea what frequencies this would output as is, but the circuit is simple enough that you could calculate that from the component values. Powering it up and looking at the output sounds easier, though 😀 You may have to replace the 555 timing capacitors to bring things into the audible range, and the next step is then to replace the timing resistors with pots. You can also mess around with the 54C221 timing components. A bit like a mil-speced dual Atari Punk Console 🆒 ---
**Author:** ![MarkKelsall](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/markkelsall/32/1261_2.png) [@MarkKelsall](https://lookmumnocomputer.discourse.group/u/MarkKelsall)\ **Post date:** [June 14, 2020, 1:45pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/14 "2020-06-14T13:45:05Z")
This would be a Nato Punk console, as it has a proper Nato number… as it was used for testing Lynx helicopter radars apparently! The 555s are easy enough to get pinouts and circuit diagrams for. Could just draw a diagram… Got a nice little self contained mono amp for just such a project! Was going to chuck the board out, but spotted the 555s… ---
**Author:** ![devicex](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/devicex/32/28_2.png) [@devicex](https://lookmumnocomputer.discourse.group/u/devicex)\ **Post date:** [June 25, 2020, 10:34pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/15 "2020-06-25T22:34:36Z")
that is some pretty cool surplus stuff , it will be fun to see what you do with it . ---
**Author:** ![MarkKelsall](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/markkelsall/32/1261_2.png) [@MarkKelsall](https://lookmumnocomputer.discourse.group/u/MarkKelsall)\ **Post date:** [June 25, 2020, 11:04pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/16 "2020-06-25T23:04:48Z")
I made a torch with the empty shell, recycled LED lamp turned to fit on my lathe, recycled lithium cells from a broken bike battery re-welded together in a funny shape to fit the case and some standard DC DC converters plus a latching solenoid switch unit and an extra LED indicator lamp. Still got the original circuit board laying around in the parts box. ![1566-I 4O64y,](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/56c51d846dc77f5530da457966fa3610e6560930.jpeg) ---
**Author:** ![Mcshafty](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@Mcshafty](https://lookmumnocomputer.discourse.group/u/Mcshafty)\ **Post date:** [August 18, 2020, 5:43am UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/17 "2020-08-18T05:43:51Z")
![IMG_20200818_153557](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/8/839aae78ab9ac5749957b0b9115d6f6fdcd9050e.jpeg) This is mine. It was the first diy build I made that wasn’t a kit. I made a Youtube clip here at the time: [https://youtu.be/ypZVMgOxab0](https://youtu.be/ypZVMgOxab0) It’s getting surgery at the moment - I’m adding a non-inverting opamp at the end to increase the output level. I hope it still works afterwards 😂 ---
**Author:** ![Maxhirez](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/maxhirez/32/42_2.png) [@Maxhirez](https://lookmumnocomputer.discourse.group/u/Maxhirez)\ **Post date:** [August 18, 2020, 5:32pm UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/18 "2020-08-18T17:32:20Z")
Cool! Welcome to the forum, @Mcshafty! Is it using a floating-pin transistor with a hex inverter as an amplifier? ---
**Author:** ![Mcshafty](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@Mcshafty](https://lookmumnocomputer.discourse.group/u/Mcshafty)\ **Post date:** [August 19, 2020, 12:24am UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/19 "2020-08-19T00:24:30Z")
Cheers for the welcome. I don’t think it’s either. I tried adding a standard non-inverting opamp circuit (TL072 4.7k/47k) after the output of the noise circuit. I found that the 12v version of the layout at the top of the the post to be very quiet. I did build a separate amplifier module using a non-inverting opamp schematic and that worked so I thought it would be good to combine them. Anyway, It didn’t work 😠. But I’ve only been doing stripboard layouts for a few months and I’m learning as I go. It could be poor soldering, a misplaced component or a fundamental design flaw. I’ll revisit it in a few days with fresh eyes. In the meantime, I built this “Roland System 100m” LFO (that does work) to play with. ![IMG_20200818_180748.jpg](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/4/4fa125e3ca970d32ab065b27fcd33da348cb61d4.jpeg) ---
**Author:** ![Janvier](https://avatars.discourse-cdn.com/v4/letter/j/b3f665/32.png) [@Janvier](https://lookmumnocomputer.discourse.group/u/Janvier)\ **Post date:** [May 12, 2021, 8:47am UTC](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355/20 "2021-05-12T08:47:40Z")
Hello guys, I’m having issue whith this schematic. No white noise on the output, double checked everything. Maybe it’s because I’m using ceramic capacitors ? Anyone have an idea ? ![16208092140307413461219739670600](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/3/327906f9b64969663bf7862d23b4a9e0718a9d9c.jpeg) [Next page](https://lookmumnocomputer.discourse.group/t/schmitz-white-noise-generator/355.md?page=2)