SDIY Class # 10 - Building a dual Mixer with Otto's DIY
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- เผยแพร่เมื่อ 13 ก.ย. 2024
- Today we put our Opamp theory in practice, building a super useful dual mixer module for Eurorack, using the excellent Otto's DIY prototyping system.
intech.studio/...
/ quincas
I like your pace of speech. Its easy to follow you. Awesome as heck video!
In case you needed to know these are the best electronics synths videos ever.
Agreed 110%!
I don't have any particular interest in music, audio, synths… but this video fascinates me. Love this kit and this technique of building panels!
I love you , Synth Diy Guy
Old time electronics DIYer here (back to the 1970s when I was in HS), Quincas, your channel is excellent, not only do you discuss the circuit designs, but also building tips and ideas. Also unlike many other DIYers that build their own from "scratch" rather than a kit, your videos make it easy for anyone to make one too, as many never provide the schematic. I went to the website for the boards, but unfortunately they no longer seem to be sold; possibly because they never sold many of them. Too bad, as they do provide a nice platform for a modular DIYer that builds more than just kits. Oh yeah, I also have to say that it was only when I saw someone comment on another video that I realized that you live in Mexico City; I knew you were of Mexican heritage but because your English is so flawless, I thought you were maybe somewhere in the U.S.! Curious as to what setting you learned English in, as you're "accent" is pretty much unoticeable.
Thanks for your encouraging comments! I do live in Mexico City, but I was born and raised in Brazil! And then I spent 8 years studying music in the States. My Dad lived in New Jersey since I was 5 and I would visit often, which I think gave me the foundation for my better-than-average-for-a-foreigner english :) Cheers!
Well that explains everything. Never been to Mexico, but I did visit Brazil once - Rio and Salvador. You don't have a Jersey accent either, and I'm guessing vocé fala portugues too. I know a little, but I know even more Spanish although that's really not saying much. Hopefuly my two grandchildren whose father is Dominican will be bilingual . I'm in central NY state myself. And again, your videos are the best of any DIY synth videos I've watched on YT. Major kudos to you!
Nice build!
I would have liked to see some of your troubleshooting and fix-up process, though, as that's where I sometimes (often!) struggle in my own builds. :)
Thanks! I thought the video was super long already, which is why I didn't go into detail of my troubleshooting. But basically, some inputs were not working so I used the Multimeter continuity tester to follow the signal, from the jack to the pot to the circuit. Each time I found a bad joint or a connection I had failed to make, fixed it and done!
Synth Diy Guy I was going to say the same thing actually. I'm really new to electronics and you might not realise how something that seems so simple to you can be a mystery to a beginner :)
A video on trouble shooting a build like this would be really useful I think.
Thanks, I'll keep that in mind :)
I agree, please include troubleshooting segments in your videos, that way we can learn even more from you!
i realize I'm kind of randomly asking but does anyone know of a good website to watch new tv shows online?
I stripped a 50” plasma tv. Removed the plasma panels and I’m going to use the solid aluminum backing for my panel. Lots of room and it still looks good in the box. May take me a few years but at least I will be able to operate it blind.
really enjoying the way u talk! please more on protoboard... allkinds of vcos, filters, adsr...
iam really new to diy and the protoboard would be my next stage before finalstage own pcb...
thank you for this video
thanks! I have a load of kits in line to review right now, but soon I'll do more protoboard stuff :)
Excellent video. I will definitly bare this circuit in mind for my project. Loved the tip on not triming off the leads.
As I remember from my old days of education in Electronics, the better way is to trim the leads first. Then soldering them (gives you less chance of having "cold/bad" solderjoint), and finaly use the excess or some other (ideally beforehand stretcht, to make them straight) silverwire for the connections.
(Last time i did this must be 29 years ago....)
13:25 Bob Ross of electronics
I'm honored!
Nice explain 👏🏼👏🏼👏🏼
Great video
thanks!
That was very cool.
Amazing information , thanks
If you go to the Otto's DIY facebook group I added some printable layout sheets for all the different protoboards.
Awesome! Thanks :)
Great build. Excellent to see. Agree with @yoknapatawpha as someone new to scratch build, I would appreciate some troubleshooting and fix process. This now goes in my book of 'Things to Build' Nice work.
thanks!
Beautiful! What exactly is happening in the second mixer where you say you mix the sequencer signals together?
Just dc coupled mixing, meaning you can mix cv signals, not just audio
Very Helpful. I am looking for more information on how the power is connected from the case to the module. That little yellow strip looks useful. I would like to some day learn how to build some modules from scratch. What is the most simple thing to make?
hey! this is probably the simplest thing you can make and it's super useful! Stick two of these behind a panel:
th-cam.com/video/8BOnvSQpoGY/w-d-xo.html
Wow! Take care your fingers!!
Nice! I received yesterday my Otto’s shipping... which opamps did you use here? Other you do recommend? Thanks!
Hi! I used the TL074 because I'm just used to it and know it works. There are better opamps these days, but I don't think they are necessary for something as simple as this.
I was cutting resistor leads after soldering them to a pcb, and a tiny bit flew into my eye .. no damage, but shows that even glasses are not always enough protection.
When drilling, I would suggest putting a couple of screws into the corner holes into the wood below. Then the board will stay still while you drill.
Why does your solder smoke rise straight up, while mine always drifts toward my face? :-(
Great tips, thank you! I had a fan blowing out my window and thus pulling the smoke away :)
Always secure you're workpieces. Duck tape helpes :p you said, watch about your eyes and mates but what about your fingers? You can't twist knobs without.
Thanks for that easy peasy mixer :)))
Hey bro, I love the channel. I have learned so much about circuit bending old toys to use with my Pocket Operators. Could I ask you a question? So my father works for a wire harness factory which creates chassis for forklifts and automotive parts, they have access to female/male terminals, Deutch LADD and Kometsu socket/pin connectors, pots, switches, different wire lengths and cables, and my dad said he'd get me a kit together and solder for DIY projects like yourself! He'll get me all the parts, and all I need to get is the breadboard basically. I actually worked with him before and used the Cirrus test board with ribbon kits to test different harnesses! Anyway, I don't exactly know what to ask him to get me, I was thinking a general multi-cable would be cool with male/female ends for all possible pin outs for audio and media/TRS/1/4/1/8 and Stereo 3.5mm plugs. As for a modular hub to interact with CC mappings and USB host data (gonna program a Teensy Audio Library chipset eventually) what parts from my dad's job would you suggest I ask him to started assembling some of your projects? I want a synth hub to plug all my devices into and use it with patch cables/POs for sampling from my Phone/Tablet. Essentially I would be building a frame which can fit inside of a plastic toolbox which can open and close or a bigger briefcase to house everything; special components would be an LCD waveform analysis synthesizer module with velocity pads, arcade buttons, 3.5mm stereo inputs for Pocket Operators and Korg Volcas (CV Gating) and Pulse Width Modulation. USB power bank to power everything. Now I'm still new to all of this, but I already have access to the tools - a stable wooden desk to work on, soldering gun, solder, heat shrink, 10/12/14/16 gauge wire, amps, but I need 10k resistors like you mentioned. My dad said a lot of their parts come from Digikey which they already have in inventory. I'm trying to understand the necessary components to start going mad scientist and taking apart my old electronics and toys as donors to transplant onto a new circuit board with the new parts to make it all work together. Hopefully some of that made sense lol. Watching you solder the wiring on the back reminded of the DIY Apple Disk II kit, where you have to route and layer the wires to build using hex machine code the CPU, ROM, and RAM! Thank you and have a great day!
Hey! Sorry for the late reply!
Sounds like your dad has a fun job with a lot to offer you! But I think in order to gain the basic knowledge so you can know what to ask him for, you should start assembling some simple cheap kits. You'll start realizing what values of resistors and capacitors, what type of chips and transistors are most used, etc...
Check out my "easy beginner kits" playlist, start with some of those. You'll need a case and Power supply to start. My video on the Befaco Lunch Bus might be useful, maybe you and your dad can build your own box to fit the power supply and rails in. Digikey has the rails you need, they are called Vector rails.
Good luck!
@@QuincasMoreira So, I tried to make a list of components to ask for as they've got plenty from Digikey and other parts depot places. I have 6 pocket operators, so I'd like to use alligator clips or something to make contact and use them with arcade buttons like you did. Some kind of non-destructible build using pogo pins could work? Have you seen the Pocket Operator Midi Adapter on Tindie made by Hanz? Do you have a list of the required parts which I could cross reference with him? I actually worked with him for a few years, so I know how to point the diodes the right way, capacitors/transistors/relays/amps etc. Some of the harnesses we built were military grade and went into helicopters. We had to cover them with conduit or braid to protect the wires. It's like I've got the skills to do it, but just don't know where to start, haha. Thanks for all your help!
Hi Quincas! My mixer is rocking great, thanks for your videos! but I have a question going around for a few weeks: I am close to finish my rack space and I need to keep an eye on consume. How would you calculate consume of this mixer or for example the deadbug buffer? is there an amount of + and - miliamps that we can reserve for each TL074 in DIY builds? Thanks!
Hola Sergio! So, current consumption depends on more than just the number of ICs and components, it has more to do with what the circuit is doing. You can measure it by using your amp meter in line with me module's power supply (current goes through the meter before it hits the module). Or you can get Joranalog's test 3 module which is made for this purpose. Another idea is to look for a similar module at Modular Grid and see what it says under current consumption. It's likely that any mono mixer will draw about the same. Saludos!
Love it but it's huuuuge! Why not use board for ground rails?
Well, that's the size the boards came in, they make smaller ones too. It's relative, if you have a large system it's nice to have wiggle room. and you can make some passive mults with the leftover space. And I'm not sure what you mean, I did use parts of the board for ground, and other parts where it wasn't practical to do so I used wires.
Does anyone know how one can get this DIY kit nowadays?
How do you like that Rigol scope? I'm tempted to get one but it would probably be overkill for my modest purposes...
I love it! It was a gift from Ray Wilson's widow, so it's dear to me. It is definitely overkill for my modest purposes but it's nice to have a nice size screen and four channels. You can get the cheaper model though, and hack the firmware to make it do the same as this one: www.instructables.com/id/Hacking-the-Rigol-DS1052E-Oscilloscope-with-Linux/
Take care of that scope :-)
would it be possible to convert this into a stereo mixer where one pot controls the level for both channels at once?
Yes! you would need doubled pots, they exist!
Are you just using solid solder to bridge those grounds across the board?
No it's wire! I just removed the plastic from some solid core wire
Synth Diy Guy ohhhh is that what people do? I see it all the time in DIY stuff but no one bothers to explain it! Thank you!
@@BeniRoseMusic Yeah, sometimes it's better, like for grounds where the same wire has to go to many places :)
Synth Diy Guy ya, I have definitely struggled to solder two wires to the same ground before and thought “there has to be a better way!” And then saw this kind of thing but wondered what they were using. Guess it’s one of those “so obvious no one mentions it” kind of things to just take a solid core out of the shielding.
@@BeniRoseMusic there you go ;)
I know this was a while ago, but what was the reasoning behind using the opamps as inverting amplifiers twice? I'm just curious if there was a reason 🙂 thanks
Yes, this is how every opamp mixer is made, dual inverters. noninverting is only good for amplification purposes.
@@QuincasMoreira awesome, thanks! I'm going to have to read more I guess 😄
"The advantage of using an op-amp inverting amplifier is that the summing point is virtually at earth potential and therefore the settings and signals from each different channel do not affect each other. In this way each channel can be summed or mixed regardless of the signal level, source impedance and the like."
@@QuincasMoreira thanks again for the help! 👍 I ran to that Texas instruments opamps handbook again right after you replied. I guess I still basically use opamps as they appear in schematics and never thought about the "why" of the inverting input before
How much did this cost you?
Nothing, I get all kits for free to make videos! Check at the Otto's site how much they charge for their kits. The resistors, caps and IC cost next to nothing.
where to take the circuit with capacitors?
The two Electrolytics (10 uf) go where power enters the circuit. One for each power rail, be careful of polarity. On the negative rail, Cap negative to -12, Cap positive to ground. On the positive rail, Cap positive to +12, Cap negative to ground. The two ceramic (non polarized) 100nf decoupling caps go from each power pin to ground, as close as possible to the pins themselves on the Opamp.
Synth Diy Guy tnanks ! Great work! Great work! Could you explain beginners how to make lfo eurorack module using plain parts? This would be very much appreciated.
Thanks! I will try to make such a video, but it may take a while, I have a lot of kits to review right now! Check out projects with the CD40106. It has 6 square wave oscillators, but you can also get a triangular like shape out of the inverter inputs and make opamp buffers for them: www.fluxmonkey.com/electronoize/40106Oscillator.htm
BMX Hemoglobin mixer
What's that?
maybe a joke about my bleeding hand? lol
oh sorry about that I was randomly naming your module based on the pot points and the blood you put into it.
I wouldn't make fun of you being hurt tho. thanks for the video!
hahaha, no need to apologize, it just took me a minute to catch your drift ;)
According to the youtube algorithm, after 2 yares i see this video. This kind of mixer is not the best choice. Becouse all of tree inputs are paralel. One affect the other. The sum of the resistances!
that´s just not true! If it was passive sure, but they are going into an inverting amp, so no. Pretty much every eurorack audio mixer is done this way