# 1184 quad mixer vca (AKA 1183) **URL:** \ **Category:** KOSMO MODULES\ **Created:** [March 27, 2020, 2:27pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455 "2020-03-27T14:27:11Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![lookmumnocomputer](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lookmumnocomputer/32/23_2.png) [@lookmumnocomputer](https://lookmumnocomputer.discourse.group/u/lookmumnocomputer)\ **Post date:** [May 27, 2020, 1:30pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/21 "2020-05-27T13:30:38Z")
indeed!!! first thing I say when I get an email is reflow all the solder points, cus yeah it makes sense on a socket cus the more its pushed in the further the solder moves from the pad! so yeah makes sense glad thats now working!! šŸ˜ƒ but still no mix out? ---
**Author:** ![fluxpavilion](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fluxpavilion/32/2475_2.png) [@fluxpavilion](https://lookmumnocomputer.discourse.group/u/fluxpavilion)\ **Post date:** [May 27, 2020, 1:49pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/22 "2020-05-27T13:49:41Z")
yeah still no mix out as of yet! ---
**Author:** ![fluxpavilion](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fluxpavilion/32/2475_2.png) [@fluxpavilion](https://lookmumnocomputer.discourse.group/u/fluxpavilion)\ **Post date:** [May 27, 2020, 1:51pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/23 "2020-05-27T13:51:42Z")
amazing let me have a look, what would be a good way of checking signal at those points? using a multimeter? ---
**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 27, 2020, 2:10pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/24 "2020-05-27T14:10:17Z")
Try this: > [@Need some help with the kosmo vco w/ tuner. Please! Iā€™ve lost weeks](https://lookmumnocomputer.discourse.group/t/need-some-help-with-the-kosmo-vco-w-tuner-please-i-ve-lost-weeks/691/30): > > I think you should find out which parts of the circuit are working and which are not. And I agree with @analogoutput that you should concentrate on the analog side of the circuit first. One way of tracing AC signals, if you do not have any specialised equipment like an oscilloscope, is to use an audio amplifier. It basically boils down to that you probe the circuit and listen whether you can hear a signal where you would expect one. This should work with an oscillator as all it will produce (moā€¦ Hereā€™s a picture, the cap is smaller than what Jos was suggestingā€¦ ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/e/ee828808dceddf70825e67dff0e4f5d0e590bfcd.png) ---
**Author:** ![lookmumnocomputer](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lookmumnocomputer/32/23_2.png) [@lookmumnocomputer](https://lookmumnocomputer.discourse.group/u/lookmumnocomputer)\ **Post date:** [May 27, 2020, 5:22pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/25 "2020-05-27T17:22:11Z")
> [@fluxpavilion](#): > > amazing let me have a look, what would be a good way of checking signal at those points? > > using a multimeter? I still do that all the time! Iā€™ve got a rather cooked hifi speaker I use. however I must confess all I do is use a mini jack cable, put the shield to the ground of the circuit with a bit of tape and use the other end and just plop it on all of the component legs till I hear something remotely alternating and oscillating. many times an almighty bang happens but im yet to pop a speaker cone, however its seems like a challenge! ---
**Author:** ![fluxpavilion](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fluxpavilion/32/2475_2.png) [@fluxpavilion](https://lookmumnocomputer.discourse.group/u/fluxpavilion)\ **Post date:** [May 27, 2020, 6:20pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/26 "2020-05-27T18:20:30Z")
Really helpful knowing what components to be checking @analogoutput thank you I thought Iā€™d have a solderrecheckk and saw one of my pins from the TL072 socket didnā€™t make it into the hole and was bent out Replaced the socket and hey presto! Works a treat, Iā€™m definitely learning that troubleshooting isnā€™t as complicated as it may seem, I really wanna learn how to check a schematic and know what elements are involved in what part of the process Iā€™ll guess that will come in time the more I do this! ---
**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 27, 2020, 6:25pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/27 "2020-05-27T18:25:48Z")
Pushing ICs into sockets always gives me paranoiaā€¦ ---
**Author:** ![fluxpavilion](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fluxpavilion/32/2475_2.png) [@fluxpavilion](https://lookmumnocomputer.discourse.group/u/fluxpavilion)\ **Post date:** [May 27, 2020, 6:30pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/28 "2020-05-27T18:30:12Z")
haha me too! funny thing with this one is that it wasnt the ic but the socket itself that got a bent pin, not even sure how i managed it! ---
**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:** [May 27, 2020, 10:08pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/29 "2020-05-27T22:08:45Z")
What i do is use the table to slightly bend all the pins inward all in a level-ish way (carefully). ---
**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:** [May 27, 2020, 10:29pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/30 "2020-05-27T22:29:00Z")
Yeah, I do that. Sometimes itā€™s the only way to have a reasonable expectation of a fit. ---
**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 27, 2020, 10:35pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/31 "2020-05-27T22:35:57Z")
Sure, I do that. It doesnā€™t cure paranoia. ---
**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 27, 2020, 10:38pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/32 "2020-05-27T22:38:03Z")
You want one of these: [Jameco Benchpro IC Pin Straightener Tool](https://www.jameco.com/shop/ProductDisplay?catalogId=10001&langId=-1&storeId=10001&productId=99363) šŸ˜ƒ ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/5c8d76a418fd79b4980328e12bd915d94f4423e0.jpeg) EDIT: Should point out that while I know itā€™s a thing, I donā€™t have one myself, and I usually only recommend things Iā€™ve tested myself šŸ™‚ ā€“ but my strange brain just reminded me that Big Clive (of YouTube fame) has one, and not just that, it also remembered one video where he uses it: [https://youtu.be/qfOardiykPs](https://youtu.be/qfOardiykPs) (tool appears at around 1:15:00; the video also features the [cheap hollow needles](https://lookmumnocomputer.discourse.group/t/1113-performance-filter/14/10) Iā€™ve mentioned before, and a very nice (but expensive) little desoldering pump from Japanese quality brand [Engineer Inc](https://www.engineertools-jp.com/home) that I have somewhere.) ---
**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:** [May 27, 2020, 10:40pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/33 "2020-05-27T22:40:31Z")
after still trying to put it directly by forcing a little on one side, I always end up using a small pliers to twist it slightly i donā€™t know this, excellent ! ---
**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:** [May 27, 2020, 11:44pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/34 "2020-05-27T23:44:57Z")
![20200527_1943051](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/54225f6dfdd25a521d01815beee1a3c5aa33f2a6.jpeg) I use a pair of flat jaw hemostats . ---
**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:** [May 28, 2020, 1:13am UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/35 "2020-05-28T01:13:56Z")
my luck is i would buy this thing and bend the fucker putting it in there. ---
**Author:** ![CTorp](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ctorp/32/15023_2.png) [@CTorp](https://lookmumnocomputer.discourse.group/u/CTorp)\ **Post date:** [May 28, 2020, 1:45am UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/36 "2020-05-28T01:45:09Z")
I usually just unevenly squeeze them together between finger and thumb and then shimmy/jam them right in šŸ¤£ ---
**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:** [May 28, 2020, 9:09pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/37 "2020-05-28T21:09:47Z")
Talking of bending pins, did any of you have a hard time fitting in the single pole switches? The holes in the PCB footprint are spaced out a little more than the ones for the double pole switches, so if you get all your switches from the same family, either the double pole or the single pole ones donā€™t fit quite right. I had to slightly bend out the pins of the SPDT switches to make them fit (and hear some epoxy glue cracking while doing it). ---
**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:** [May 29, 2020, 6:28am UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/38 "2020-05-29T06:28:31Z")
> [@fredrik](#): > > I donā€™t see what the diode is doing there; seems to me you could just leave it outā€¦ Yeah, the 2V Zener doesnā€™t seem to serve any purpose where it is. @lookmumnocomputer is it possible you meant to put it on the linear control voltage input instead of the signal input? > [@fredrik](#): > > The output is also a little bit odd Indeed. > [@fredrik](#): > > The first 100k doesnā€™t really do anything, what I can tell (after turning on some more braincells), since the current doesnā€™t have anywhere else to go but through it. You could probably use any value there. Or a 0 ohm link. The datasheet that I have says ā€œCurrent Outputs Capable of Swinging to Within 1,5V of Each Supplyā€ so that first 100k resistor would limit the maximum output current to Ā±10.5V/100k = Ā±105ĀµA so input signals above Ā±105ĀµAx47k=Ā±4.9V will get truncated at higher VCA gain settings. So as you say @fredrik the first resistor would better be replaced by a 0 ohm link (anything below 1k would probably have very little detrimental effect). ---
**Author:** ![lookmumnocomputer](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lookmumnocomputer/32/23_2.png) [@lookmumnocomputer](https://lookmumnocomputer.discourse.group/u/lookmumnocomputer)\ **Post date:** [May 29, 2020, 8:17am UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/39 "2020-05-29T08:17:06Z")
yeah the zener diode I have updated this on new ones I need to update the documentation I did it last week. its completely pointless. initially I had it on the cv input, it took this long for me and a friend to realise it wasnā€™t on the cv input and on the signal input. proper nelson Mandela effect. and since its not needed on the cv input as it stands. been working perfectly fine you can ditch it. however it may explain my wonky signal which im not gunna complain about a bit of character, that stuff only adds to things. but yes the newest versions don t have these diodes and ill put an update on it right now as they can be a ball ache to find for something that serves no purpose! ---
**Author:** ![lookmumnocomputer](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lookmumnocomputer/32/23_2.png) [@lookmumnocomputer](https://lookmumnocomputer.discourse.group/u/lookmumnocomputer)\ **Post date:** [May 29, 2020, 8:17am UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/40 "2020-05-29T08:17:53Z")
I have tried numerous brands of mini toggle switches and havenā€™t come accfross one that needs to be bent to fit, what one is it?? do you have a link? [Previous page](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455.md?page=1) [Next page](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455.md?page=3)