@@alvin_row I'll give you that. Some people are just natural but there is required discipline. I'm sorry I can't validate electronic music as valid and I'm sorry as I know it brings alot of people happiness. I was being a troll though and I am sorry, I was being an idiot. Honestly.
You beat yourself in every video, Moritz. I'm still stunned every time I watch your lessons. It is amazing how clear and peaceful you explain every concept. I've learned more in your videos than in my Electrical Technology class in college with a so-called professor... THANK YOU! Humans like you make the world move forward.
@@AnalogDude_ I don’t agree- maybe he is not an engineer with 40 years of hardcore experience, so there might by some error and simplifications. But I would never call it misleading.
As somebody whose electronics background was a simple class in high school (that I don't remember anything from) but who is otherwise familiar with soldering and tinkering with stuff, this explanation is great. Very clear and easy to understand for a beginner. Now I'm trying to wrap my head around how to adapt this into a matrix mixer, but struggling. It would be great if you could do a follow-up to this video for making a matrix one.
Not only did I get to hear some great acid but I got the best explanation yet on soft clipping. Can’t wait to build this one. Wish my electronics teachers had been producers too!
Oh man, I have lots of things to sort out but when I finish Im going back to learning from your videos! Im in my 30s and finding learning new stuff very difficult but alwayys wanted to know how to build circuts and how they work - ypur wideos are great help for me and fantastic gateway drug for electronics. Thank you man!
DUUUUUUDE!!!! I'm in the exact same boat! In early 30's with kids and have always been fascinated bv electricity and circuits but never took the time to learn about them. But once I dipped my toes in, I'm ADDICTED!!! This channel has been an amazing wealth of info and explains the whole process and WHY,, for building fun circuits! We got this dude!
if you want to learn you need to start at the basics. its a very long way until you have the foundation to fully understand these circuits and to analyse them
Anybody watching this video should have a basic grasp of entropy. Your brain will get worse from here on. Best case scenario, you loose your marbles slowly, gradually dissapearing into madness. Worst case... not even worth thinking about, buddy. So i say learn everything you possibly can right now, and build the highest mountain of knowledge to slide down as you age. No matter if you are 30, 40, 50, 60, take comfort in the undeniable fact that whatever physical state you are in today, everything will be worse tomorrow (presuming you are so privileged)
Excellent vid! There's really nothing new or innovative to be said about the design of an active mixer, but the way you explain it is wonderful! Due to the way you provide tidy explanations of how things work on the basic level, accompanied by examples, I now understand, among other things, why my passive resistance mixers have always resulted in signal loss, and why an inverting buffer on the output side of a resistance mixer fixes this issue. Fun moment: when you were explaining the addition of the buffer, and you said you were using a TL072 chip, I wondered, "Why does he need a dual op amp, instead of using a TL071?" Then, when you made the other op amp into an inverter, I literally said out loud, "And that's why you use a TL072!" 😆 I'm not much into modular synthesis, but as a multi-instrumentalist, I've long sought a way to mix instrument-level signals on stage. While this mixer still wants line-level signals on the input side, I think you've provided me with enough information in this single vid to understand what I would need to build. And that's saying something, as I've been trying to work this out for years! Liked and subscribed.
BTW, one thing I would have liked to see is the effect of turning down the pot on the clipping circuit, shown with the sawtooth wave on the oscilloscope.
this is such an excellent resource! seeing the different iterations of the circuit and getting an explanation of how each block works is a huge help. thank you for making this, so glad i came across your channel. i started getting interested in audio circuits a few years ago but got frustrated because i felt like i wasn't actually "getting" it, just blindly copying existing guitar pedal circuits. but i might have to go dig up my breadboard again.
Is this not hard clipping as it's diodes to ground? Soft clipping would normally be in the feedback of a opamp. At least that's how it is in overdrive pedals, I'm still learning synth stuff.
clipping is considered to be "hard" when the signal is strictly cut off at the clipping threshold, producing flat peaks with sharp angles. this sounds really harsh and digital, for lack of a better word. on the other hand, clipping is considered to be "soft" when the signal can slightly push past the clipping threshold and the peaks are rounded. this sounds warm and analog. since diodes open up gradually as the voltage applied to them increases, my design produces rounded peaks as there is no hard clipping threshold. (still, if you really crank the volume of the signal going into the clipping stage, the effect will get less and less "soft".) check it in the simulator: tinyurl.com/y4tvpuzl
Love your videos, very clear. One pedantic point, is this diode clipping type is normally termed hard clipping. Soft clipping is normally in the feedback loop of an opamp and adjust the gain applied rather than chopping off the top.
Placing the soft clipper after the mixer means that if you mix waveforms that aren't closely harmonically related you will get a lot of intermodulation distortion, producing all kinds of harmonically unrelated frequencies. Of course, sometimes you want that, like with distortion on electric guitars. But then you usually play power chords, with a fifth between the two notes to go through distorion together, so they are really closely harmonically related to avoid too much intermodulation distortion. Of course, electric guitar distortion can be a lot more nonlinear than a soft clipper. But I think that the soft clipper could be really useful to have before mixing. If you have a single melodic voice then it will be almost periodic, and then the soft clipper will mostly just make interesting changes to the harmonic spectrum, especially if it changes volume. Also, I think that it could be usedful to have a bigger than 20 k pot to ground coupled to the diodes? At the 20 k setting, assuming the diodes connect, the incremental voltage change will be 1/6 of the voltage change at the input (voltage division 100 k 20 k). That's definitely softer than clipping to one diode drop, but I think an even softer clip could be useful as well? Maybe a 100 k pot at least?
simplemente maravillosos, cada uno de tus videos. gracias y saludos desde Buenos Aires! i'd like to ask if there should be any changes on the input resistors if we feed them with instrument signals-- like input 1 and 2 are for bass and guitar, and input 3 for drum machine. thanks again!
if you use 100k resistors for the inputs and the feedback resistance (like i do in this design), then each channel will have unity gain (meaning that the signals leave the mixer at the same volume that you send them in). if you want individual channels to have more gain, you can reduce their input resistance. e.g. if you use 50k at the input while leaving the feedback resistance at 100k, that channel will have a gain of 2.
I have never built one using an opamp, but I see the prinsiples are likevise using transistors. Interesting to (finally) seeing a explanation of how the inverse (second) opamp works. Nice video.
I made the circuit as shown at 17:48 used it on an acoustic guitar mixing together a small condenser mic and a piezo pickup. The microphone sound lost some of the upper frequencies and sounds a bit muddy. Not sure what the culprit is here. Should I try a different opamp IC?
Piezo pickups have extremely high output impedances, the mixers input impedance is too low so it is loading down your signal. To fix this you could add another op amp configured as a unity gain buffer (opamp output connected to -ve input, piezo connected to +ve input) between the pick-up and the mixer input, this will give the high input impedance required. The alternative would be to use a piezo pickup preamp, which may be preferable as piezo pickups often need some equalisation to sound right.
Did you put some form of compression after the mixer in the demo, or was it just the saturation? When the kick came in you could hear a really pleasing side-chain style pumping in the chords and if that's an inherit of the mixer is is incredible
I believe the effect comes from the signal getting quieter, the more it distorts. You can also see this in the simulation and monitor the output voltages of the normal and distorted outputs. Because the kick is a strong signal, it distorts more when the kick hits and the signal ducks down. On my built of this mixer I included a wet/dry-mix knob to blend the two signals so I can have the effect with the volume and punch of the clean signal :)
The demo from the beginning is a mover! Where we can hear more of your musical work? As for the presented synth concept I wish to thank you! It is of high value, as always!
On 8:30 you change the circuit to add the signals together. But this got me thinking: In your schematic, you add 5v + 5v to get -10v. Wouldn't this possibly damage other circuits? Let's say I got 3 VCO's at 5v, and I add them together. According to this schematic they become 15v. If I would feed this into another module, won't this cause some damage? I know, with a potentiometer I could adjust the levels that they would only account for 33% or something so this won't happen, but shouldn't there also be a failsafe that the output would always stay between -5 and +5? Or is this something I do not have to worry about? Disclaimer: I am a very noob with DIY stuff, but I do think that this mixer will be my first project.
valid question - the “failsafe” you mention is actually the supply voltage. in my case, that’s +/- 12V. the op amp cannot push out voltages higher or lower than that. and as long as every other module works with the same supply voltage, there shouldn’t be any problems.
@@MoritzKlein0 Thanks! I want to make this mixer to mixer 3 oscillators into one, so they can go into a filter. Is 12v then safe to use? I am very new and don't know what's the default voltage an oscillator outputs and I don't have an oscilloscope to measure what my East Beast and Chipz oscillators outputs (those are the one I want to mix)
Great video mate! Really appreciate what you've done with these series of videos. It is my understanding that EQs are be simple circuits, perhaps that would be a interesting addition to the simple grit mixer?
I think this might be the fifth time I've watched this. Every time I glean something new. Thanks MK, ultra cool. You're a really good communicator. (Never built this actual circuit by the way, just learnt a lot)
You could create an AVC type feedback voltage from the inputs with adjustable slew rate control. Then connect that to a couple of op amps driving the clipping diodes, clip level & AVCFB is now driving the op amps. Now it will dynamically track and clip the input level. You could even add clip & slew CV's.
Ah I didn’t experiment with both out puts, I’m just trying to use the build without distortion and making for guitar looping etc, can you explain how I could implement both of these outputs bro?
Love the sound and tried to build one on breadboard.. the mixer part works just finde, but I don't get any clipping out of the diodes :/ I did every troubleshooting I could think of, but to no avail. I'm powering the breadboard with the double 9v-battery configuration as described in the manual for the module: is it possible, that there just is no clipping, when the circuit is powered with 9v instead of 12v? I'm grateful for any advice :)
Hi Moritz , does this mixer just run off single 5v power supply or am I missing something? I can’t quite get this thing working, I noticed you have another ground in video I could be mistaken, Ive watched this video so many times 😂 pls help
It needs dual +ve and -ve supply rails, usually mixers have fairly high voltage rails like +-15v to give plenty of overhead, but +-9v would be fine too. The TL072 is not really suitable for use at 5v, the output swing would be extremely limited.
Hey Moritz, how many volts of power do you need for this circuit to work? What kind of power plug out of the wall would one need to get (in terms of volts and amps supplied by the power plug)
that depends on the signals you're trying to mix. the supply voltage will determine the maximum output volume of the mixer. i use +/-12 V in this video!
@@MoritzKlein0 thank you for the answer! I am planning to make a simple summing mixer with an active circuit a la this one but I have concerns regarding fire hazards when using an actual power supply. Are there any precautions I should be taking? Kind regards
With the passive average mixer (around 3:10), why can't we use (say) 1 ohm resistors, to allow more source current through? I'm avoiding saying 0 ohm explicitly here, but that's what I'm suggesting. Is it something to do with protecting each input from its sibling's current? Also, how do we arrive at 100k? Why not 1M? etc. Thank you!
good question - so the pitfall with using lower resistance values is mainly power usage. if we used two 1k resistors, for example, there'd be a rather large amount of current flowing between the two inputs (from the one where the voltage is currently higher to the one where it's currently lower). let's say we send in two eurorack oscillators, which are 10 V peak-to-peak (i.e. oscillating between 5V and -5V). worst case, we have 5V at input one and -5V at input two. that's 10V across 2k ohms worth of resistance, resulting in a current of 5 mA. this current is just "lost", because it always flows, no matter what else we're driving with our circuit. if we use 100ks (and a buffer) instead, we only waste about 50 uA in this scenario - which is orders of magnitude less. check it in the simulator: tinyurl.com/y5ehgtlo as for why we don't use ridiculously huge resistors (1M, 10M, 100M?): there is something called thermal noise (or johnson noise) which scales up with a resistor's resistance value. the bigger a resistor gets, the more noise it introduces into your circuit. (see here: eepower.com/resistor-guide/resistor-fundamentals/resistor-noise/# ) so in essence, you want to balance your resistance values in a way that you don't waste too much current, but you also don't introduce audible noise. apparently, 100k is often considered the sweet spot here - which is why i use 100ks frequently. i haven't tested how noisy a 1M would be here, mind you …
@@MoritzKlein0 I see, it's about preserving upstream current, because as you say you may want to use it to drive other stages etc. I asked the question because at one point, in a further iteration we added an op-amp because we didn't have enough current to drive speakers/earphones (?) - my reaction while looking at such a simple circuit was "remove those resistors!". I knew it was wrong, but not why. As a rule then, we preserve current when we only need to know voltages, and then we supply current right at the point we need power (such as speakers). I've learnt so much from your videos, thank you!
This is exactly what I needed. Your videos are so easy to follow! Question though, I don't necessarily understand some of the terminology/electrical theory. Do you have a recommendation of a site to get the basics down?
you could try reading the manual to my DIY VCO kit - it‘s very much intended for complete beginners and explains all the basics in detail: www.ericasynths.lv/media/VCO_MANUAL_v2.pdf
hey, thanks for enlighting us. you mention in the video, that you will occure the panning topic in an other video. did you so far? or do you know a good reference, that is easy to understand/read about panning / voltage controlled panning circuits? thank you
Am I able to use a TL074 for this instead of 2) TL072’s? I am still very new to this and any help is appreciated. I really enjoyed the video and explanations, so thank you. Subscribed and looking forward for more🤙
Hi! I used to use the TL072 in my own pedal designs, very nice opam :D you can alsp use other diodes, like LEDs or germanium if you find them, to change the kind of effect you get from the clipping stage. Thanks for this amazing video 😀
Hi Moritz! Mega videos, ich bin relativ frisch in dem ganzen Synthie spiel und erinnere mit deinem Videos gleichzeitig meinen Großvater, der mich schon in jungen Jahren als ehemaliger Physiklehrer an Schaltungen und Elektronik herangeführt hat. Dafür schonmal ein riesiges Dankeschön! Nun zu meiner Frage: planst du, in nächster Zeit nochmal ein follow up zu diesem Video zu machen? Besonders mit Kompressor + Sidechain wäre mein Interesse riesengroß! Viele Grüße Ben
@@MoritzKlein0 Hi Moritz! Vielen dank! eine weitere Frage hätte ich noch: wie würdest du kompressor und sidechain integrieren? Pro kanal in und umschaltbar, oder einen dedizierten kanal dafür durch den man das routet oder hinter den mix als output?..
in the video i‘m using a split 12V/0V/-12V power supply, but you can also use 9V batteries. you‘ll need two to create a fake 9V/0V/-9V supply - check my VCO series for an explanation on how that works.
i have a little question, does the signal get at half the volume when one of the channels is sitting at 0 if i dont have an opamp after? thats because i think for me it migh be easier to just go to an audio interface and amplify the signal there
Great stuff, really informative. How about as one of the advanced features you add VCA control (per circuit in a previous video) rather than/in addition to fader pots? Perhaps also VCA controlled panning. Badass mixer!
I stripboarded this and made a 6 ch version. I couldn't figure out why the distortion was awful until I realized I missed the 100k between the two opamps, doh! Very easy and nice
I had a question. If i have 5 inputs with 5v amplitude in phase, for output i have -25v. But i had just +/-15 v in power supply. I think it will have distortion. How to get rid of it?
I love your videos n.n they're also an inspiration for me, but I have a question: can you use a lm386 as opamp? I'm having issues with the tl series;---;
Hi, I'm trying to go for the adjustable mixer, skipping the last opamp because I'll use it as an audio mixer and want to save one op amp to make a gain knob. I'm facing a weird issue. The mixer seems to not working until I remove the connection between Non-inverting input and ground... In this case, it's seems to work fine. Any idea why ? I mean, it's working so I'm fine with this solution but I would like to understand if there is any reason + wanted to know if it's safe for the components and the circuit ?
This is extremely cool. Do you have a bio? How did you learn and how long have you been doing the music and the circuitry? I'm a junior EE and it's all still pretty daunting but this is very inspiring.
just because you can also adjust the amount of clipping by dialing down the input volume. i think of the trimmer as a set-and-forget for the *maximum* clipping intensity.
what if i have 3 inputs and 3 outputs all inputs going to every output but each output individually controls the inputs volume without signal interference?
Man your videos are fantastic! Thank you for making this. I've been wanting to make a Pocket Operator Output Mixer for a while now. Might have to give this a try. Really looking forward to your stereo mixer discussion. You earned a Patreon subscription from me. Nice work 👍
it's easyer to think of the voltage divider as adding them and then finding the midpoint, (5+1)/2 = 3 it's even algebraically equal (5-1)/2 + 1 5/2 - 1/2 + 1 5/2 + 1/2 (5+1)/2
I tink that what Is in the circuit Is more an hard clipping circuit with variabile treshold, am i correct? If you have time can you treat soft clipping and saturation? i Always dreamed to emulate tape sat with diodes in some way... Good job anyway
*copied from above as someone asked a similar question:* clipping is considered to be "hard" when the signal is strictly cut off at the clipping threshold, producing flat peaks with sharp angles. this sounds really harsh and digital, for lack of a better word. on the other hand, clipping is considered to be "soft" when the signal can slightly push past the clipping threshold and the peaks are rounded. this sounds warm and analog. since diodes open up gradually as the voltage applied to them increases, my design produces rounded peaks as there is no hard clipping threshold. (still, if you really crank the volume of the signal going into the clipping stage, the effect will get less and less "soft".) check it in the simulator: tinyurl.com/y4tvpuzl
Hey Moritz, even rewatching your explanations of how these circuits work, I feel like I'm still missing something that'll help me understand it. Try as I might I've never "got" how circuits actually do what they do. Any recommendations for books or online series to watch to really learn it from the bottom up?
did you watch my DIY VCO series of videos? i feel like i went much slower and used easier analogies there, maybe it's worth a try. other than that: i really recommend playing around with a circuit simulator (e.g. www.falstad.com/circuit/circuitjs.html ) - start simple, think about what you want to achieve (passive mixing might be a good starting point), set up a simple circuit and see what happens.
IMO the best thing about your videos are the music demos of the gear you’ve built, reminding everyone what we’re building these modules for
Eit👌🏽
Because it's easier to learn how opamps and diodes works than practice a real instrument with a metronome everyday of your life since childhood
@@jstro-hobbytech I don't think you need to practice with a metronome every day of your life to be a good musician.
@@alvin_row I'll give you that. Some people are just natural but there is required discipline. I'm sorry I can't validate electronic music as valid and I'm sorry as I know it brings alot of people happiness. I was being a troll though and I am sorry, I was being an idiot. Honestly.
@@jstro-hobbytech Aww, what a cute superiority complex you've got there.
You beat yourself in every video, Moritz. I'm still stunned every time I watch your lessons. It is amazing how clear and peaceful you explain every concept. I've learned more in your videos than in my Electrical Technology class in college with a so-called professor... THANK YOU! Humans like you make the world move forward.
He really does an amazing job explaining, narrating and teaching.
One of the most criminally underrated channels I've ever come across. Fantastic as always
Totally agree :)
@@AnalogDude_ I don’t agree- maybe he is not an engineer with 40 years of hardcore experience, so there might by some error and simplifications. But I would never call it misleading.
the best DIY teacher on the internet strikes again
This is great. Talking through hand drawn diagrams on dot grid paper is very beautiful and engaging.
that intro jam is fire!
This is one of the best explanations of how op-amps function I have seen! So cool!
Shout out to the LEDs and caps still patiently waiting for a chance to play.
I need a full version of that demo track. Awesome tutorial.
As somebody whose electronics background was a simple class in high school (that I don't remember anything from) but who is otherwise familiar with soldering and tinkering with stuff, this explanation is great. Very clear and easy to understand for a beginner. Now I'm trying to wrap my head around how to adapt this into a matrix mixer, but struggling. It would be great if you could do a follow-up to this video for making a matrix one.
Not only did I get to hear some great acid but I got the best explanation yet on soft clipping. Can’t wait to build this one. Wish my electronics teachers had been producers too!
Oh man, I have lots of things to sort out but when I finish Im going back to learning from your videos! Im in my 30s and finding learning new stuff very difficult but alwayys wanted to know how to build circuts and how they work - ypur wideos are great help for me and fantastic gateway drug for electronics. Thank you man!
We are all on the same boat
DUUUUUUDE!!!! I'm in the exact same boat! In early 30's with kids and have always been fascinated bv electricity and circuits but never took the time to learn about them. But once I dipped my toes in, I'm ADDICTED!!! This channel has been an amazing wealth of info and explains the whole process and WHY,, for building fun circuits!
We got this dude!
if you want to learn you need to start at the basics. its a very long way until you have the foundation to fully understand these circuits and to analyse them
Don't wait till you're in you're forties to start learning those new things. Take it from me.
Anybody watching this video should have a basic grasp of entropy. Your brain will get worse from here on. Best case scenario, you loose your marbles slowly, gradually dissapearing into madness. Worst case... not even worth thinking about, buddy. So i say learn everything you possibly can right now, and build the highest mountain of knowledge to slide down as you age. No matter if you are 30, 40, 50, 60, take comfort in the undeniable fact that whatever physical state you are in today, everything will be worse tomorrow (presuming you are so privileged)
You completely fooled me into thinking you had a 303 in that first tune.
Such a lovely demo in the beginning! 😍
Excellent vid! There's really nothing new or innovative to be said about the design of an active mixer, but the way you explain it is wonderful! Due to the way you provide tidy explanations of how things work on the basic level, accompanied by examples, I now understand, among other things, why my passive resistance mixers have always resulted in signal loss, and why an inverting buffer on the output side of a resistance mixer fixes this issue. Fun moment: when you were explaining the addition of the buffer, and you said you were using a TL072 chip, I wondered, "Why does he need a dual op amp, instead of using a TL071?" Then, when you made the other op amp into an inverter, I literally said out loud, "And that's why you use a TL072!" 😆 I'm not much into modular synthesis, but as a multi-instrumentalist, I've long sought a way to mix instrument-level signals on stage. While this mixer still wants line-level signals on the input side, I think you've provided me with enough information in this single vid to understand what I would need to build. And that's saying something, as I've been trying to work this out for years! Liked and subscribed.
BTW, one thing I would have liked to see is the effect of turning down the pot on the clipping circuit, shown with the sawtooth wave on the oscilloscope.
The algorithm gods have blessed me today. This was absolutely phenomenal! Can't wait for more, subscribing now!
this is such an excellent resource! seeing the different iterations of the circuit and getting an explanation of how each block works is a huge help. thank you for making this, so glad i came across your channel. i started getting interested in audio circuits a few years ago but got frustrated because i felt like i wasn't actually "getting" it, just blindly copying existing guitar pedal circuits. but i might have to go dig up my breadboard again.
this is by far the best explanation of building a mixer I've come across... thank you!
Great video! But what exactly do the white green and red cabel in the powerrails each go to? im a bit confused here
Moritz does it again! Your videos help me a lot. Thanks for taking the time to share these lessons.
thanks for the great explanation for the mixer. The op amp is set up in a summing amp mode to avoid the passive mixing. Very good :)
Fantastic narration of the concepts and practical assembly.
Excellent! Great, clear schematics and explanations. You are a master sir!
You are a genuinely good circuit design teacher! Circuitry feels like the Backrooms for electricity to me.
Is this not hard clipping as it's diodes to ground? Soft clipping would normally be in the feedback of a opamp. At least that's how it is in overdrive pedals, I'm still learning synth stuff.
clipping is considered to be "hard" when the signal is strictly cut off at the clipping threshold, producing flat peaks with sharp angles. this sounds really harsh and digital, for lack of a better word. on the other hand, clipping is considered to be "soft" when the signal can slightly push past the clipping threshold and the peaks are rounded. this sounds warm and analog.
since diodes open up gradually as the voltage applied to them increases, my design produces rounded peaks as there is no hard clipping threshold. (still, if you really crank the volume of the signal going into the clipping stage, the effect will get less and less "soft".) check it in the simulator: tinyurl.com/y4tvpuzl
Love your videos, very clear. One pedantic point, is this diode clipping type is normally termed hard clipping. Soft clipping is normally in the feedback loop of an opamp and adjust the gain applied rather than chopping off the top.
Awesome gonna try and build this.
I can't find a higher value per second channel on youtube, and probably won't ever.
It was a pleasure to learn that much! Thank you. I am looking forward to dive in into your videos!
Fully enjoying this series! Perfect edu for my brain :) That sweet jam really adds allot to the inspiration ✨
that intro song is super good, great video :)
Placing the soft clipper after the mixer means that if you mix waveforms that aren't closely harmonically related you will get a lot of intermodulation distortion, producing all kinds of harmonically unrelated frequencies. Of course, sometimes you want that, like with distortion on electric guitars. But then you usually play power chords, with a fifth between the two notes to go through distorion together, so they are really closely harmonically related to avoid too much intermodulation distortion. Of course, electric guitar distortion can be a lot more nonlinear than a soft clipper.
But I think that the soft clipper could be really useful to have before mixing. If you have a single melodic voice then it will be almost periodic, and then the soft clipper will mostly just make interesting changes to the harmonic spectrum, especially if it changes volume.
Also, I think that it could be usedful to have a bigger than 20 k pot to ground coupled to the diodes? At the 20 k setting, assuming the diodes connect, the incremental voltage change will be 1/6 of the voltage change at the input (voltage division 100 k 20 k). That's definitely softer than clipping to one diode drop, but I think an even softer clip could be useful as well? Maybe a 100 k pot at least?
Can you please do a video showing how an active splitter would work?
simplemente maravillosos, cada uno de tus videos. gracias y saludos desde Buenos Aires! i'd like to ask if there should be any changes on the input resistors if we feed them with instrument signals-- like input 1 and 2 are for bass and guitar, and input 3 for drum machine. thanks again!
if you use 100k resistors for the inputs and the feedback resistance (like i do in this design), then each channel will have unity gain (meaning that the signals leave the mixer at the same volume that you send them in). if you want individual channels to have more gain, you can reduce their input resistance. e.g. if you use 50k at the input while leaving the feedback resistance at 100k, that channel will have a gain of 2.
What a fun tutorial. Even as simple as this is, there's a lot of fundamental details that are explained without making you feel dumb. Thanks!
Holy cap that jam is a banger!!
Very cool stuff! I hope that one day you will explain how to build an EQ from scratch.
Excited for this series
I have never built one using an opamp, but I see the prinsiples are likevise using transistors. Interesting to (finally) seeing a explanation of how the inverse (second) opamp works. Nice video.
I made the circuit as shown at 17:48 used it on an acoustic guitar mixing together a small condenser mic and a piezo pickup. The microphone sound lost some of the upper frequencies and sounds a bit muddy. Not sure what the culprit is here. Should I try a different opamp IC?
Piezo pickups have extremely high output impedances, the mixers input impedance is too low so it is loading down your signal. To fix this you could add another op amp configured as a unity gain buffer (opamp output connected to -ve input, piezo connected to +ve input) between the pick-up and the mixer input, this will give the high input impedance required.
The alternative would be to use a piezo pickup preamp, which may be preferable as piezo pickups often need some equalisation to sound right.
Did you put some form of compression after the mixer in the demo, or was it just the saturation? When the kick came in you could hear a really pleasing side-chain style pumping in the chords and if that's an inherit of the mixer is is incredible
I believe the effect comes from the signal getting quieter, the more it distorts. You can also see this in the simulation and monitor the output voltages of the normal and distorted outputs. Because the kick is a strong signal, it distorts more when the kick hits and the signal ducks down. On my built of this mixer I included a wet/dry-mix knob to blend the two signals so I can have the effect with the volume and punch of the clean signal :)
The demo from the beginning is a mover! Where we can hear more of your musical work? As for the presented synth concept I wish to thank you! It is of high value, as always!
thanks! currently i just have some old stuff up on soundcloud, but i'm planning to release more music once the erica synths collaboration is through.
You are just so dang good at this.
Stereo sounds really nice!
On 8:30 you change the circuit to add the signals together. But this got me thinking: In your schematic, you add 5v + 5v to get -10v. Wouldn't this possibly damage other circuits? Let's say I got 3 VCO's at 5v, and I add them together. According to this schematic they become 15v. If I would feed this into another module, won't this cause some damage? I know, with a potentiometer I could adjust the levels that they would only account for 33% or something so this won't happen, but shouldn't there also be a failsafe that the output would always stay between -5 and +5? Or is this something I do not have to worry about? Disclaimer: I am a very noob with DIY stuff, but I do think that this mixer will be my first project.
valid question - the “failsafe” you mention is actually the supply voltage. in my case, that’s +/- 12V. the op amp cannot push out voltages higher or lower than that. and as long as every other module works with the same supply voltage, there shouldn’t be any problems.
@@MoritzKlein0 Thanks! I want to make this mixer to mixer 3 oscillators into one, so they can go into a filter. Is 12v then safe to use? I am very new and don't know what's the default voltage an oscillator outputs and I don't have an oscilloscope to measure what my East Beast and Chipz oscillators outputs (those are the one I want to mix)
This is so well explained, well done
I subscribed in the first minute, great work 👍
Sounds beautiful
The averaging inputs volume problem was kind of interesting. Makes me wonder if "jumping" inputs on a guitar amp works the same way.
Really liked this tutorial
Really interesting Moritz, off to build a soft clipper now! Lovely clear explanations as always
Great video mate! Really appreciate what you've done with these series of videos.
It is my understanding that EQs are be simple circuits, perhaps that would be a interesting addition to the simple grit mixer?
good idea! yeah, a three-band EQ should be easy enough to pull off. i‘ll add it to the list!
It’s a great idea, and yes they can be quite simple (basic RC) - glad Moritz is onboard with it.
I think this might be the fifth time I've watched this. Every time I glean something new. Thanks MK, ultra cool. You're a really good communicator. (Never built this actual circuit by the way, just learnt a lot)
Cool video, I'm wondering if it is possible to integrate fx loop on it, so each signal can have a fx.
This was excellent. Thank you, Moritz.
You could create an AVC type feedback voltage from the inputs with adjustable slew rate control.
Then connect that to a couple of op amps driving the clipping diodes, clip level & AVCFB is now driving the op amps.
Now it will dynamically track and clip the input level. You could even add clip & slew CV's.
Ah I didn’t experiment with both out puts, I’m just trying to use the build without distortion and making for guitar looping etc, can you explain how I could implement both of these outputs bro?
Can I also replace the precision trimmer with a potentiometer, just to have a bit more of knobs that I can turn?
sure! that way you get something like a ratio control for your limiting stage.
Love the sound and tried to build one on breadboard.. the mixer part works just finde, but I don't get any clipping out of the diodes :/ I did every troubleshooting I could think of, but to no avail. I'm powering the breadboard with the double 9v-battery configuration as described in the manual for the module: is it possible, that there just is no clipping, when the circuit is powered with 9v instead of 12v? I'm grateful for any advice :)
Nevermind.. I believe the signal is too low for the diodes to clip, when only using line-level signals..
@@yurig4709 exactly - the signal needs to be at least around 2 V peak-to-peak for the clipping to kick in.
Hi Moritz , does this mixer just run off single 5v power supply or am I missing something? I can’t quite get this thing working, I noticed you have another ground in video I could be mistaken, Ive watched this video so many times 😂 pls help
It needs dual +ve and -ve supply rails, usually mixers have fairly high voltage rails like +-15v to give plenty of overhead, but +-9v would be fine too.
The TL072 is not really suitable for use at 5v, the output swing would be extremely limited.
Hey Moritz, how many volts of power do you need for this circuit to work? What kind of power plug out of the wall would one need to get (in terms of volts and amps supplied by the power plug)
that depends on the signals you're trying to mix. the supply voltage will determine the maximum output volume of the mixer. i use +/-12 V in this video!
@@MoritzKlein0 thank you for the answer! I am planning to make a simple summing mixer with an active circuit a la this one but I have concerns regarding fire hazards when using an actual power supply. Are there any precautions I should be taking?
Kind regards
your channel is a gem. thank you!
Thanks for all you provide the community. Also. A sucker for crunchy acid house. The demo track slaps. Might have given me RD9-GAS.
Your demo is dope!
With the passive average mixer (around 3:10), why can't we use (say) 1 ohm resistors, to allow more source current through? I'm avoiding saying 0 ohm explicitly here, but that's what I'm suggesting. Is it something to do with protecting each input from its sibling's current? Also, how do we arrive at 100k? Why not 1M? etc. Thank you!
good question - so the pitfall with using lower resistance values is mainly power usage. if we used two 1k resistors, for example, there'd be a rather large amount of current flowing between the two inputs (from the one where the voltage is currently higher to the one where it's currently lower).
let's say we send in two eurorack oscillators, which are 10 V peak-to-peak (i.e. oscillating between 5V and -5V). worst case, we have 5V at input one and -5V at input two. that's 10V across 2k ohms worth of resistance, resulting in a current of 5 mA. this current is just "lost", because it always flows, no matter what else we're driving with our circuit.
if we use 100ks (and a buffer) instead, we only waste about 50 uA in this scenario - which is orders of magnitude less. check it in the simulator: tinyurl.com/y5ehgtlo
as for why we don't use ridiculously huge resistors (1M, 10M, 100M?): there is something called thermal noise (or johnson noise) which scales up with a resistor's resistance value. the bigger a resistor gets, the more noise it introduces into your circuit. (see here: eepower.com/resistor-guide/resistor-fundamentals/resistor-noise/# )
so in essence, you want to balance your resistance values in a way that you don't waste too much current, but you also don't introduce audible noise. apparently, 100k is often considered the sweet spot here - which is why i use 100ks frequently. i haven't tested how noisy a 1M would be here, mind you …
@@MoritzKlein0 I see, it's about preserving upstream current, because as you say you may want to use it to drive other stages etc. I asked the question because at one point, in a further iteration we added an op-amp because we didn't have enough current to drive speakers/earphones (?) - my reaction while looking at such a simple circuit was "remove those resistors!". I knew it was wrong, but not why. As a rule then, we preserve current when we only need to know voltages, and then we supply current right at the point we need power (such as speakers). I've learnt so much from your videos, thank you!
Adding a Tube stage might be awesome
This is exactly what I needed. Your videos are so easy to follow!
Question though, I don't necessarily understand some of the terminology/electrical theory. Do you have a recommendation of a site to get the basics down?
you could try reading the manual to my DIY VCO kit - it‘s very much intended for complete beginners and explains all the basics in detail: www.ericasynths.lv/media/VCO_MANUAL_v2.pdf
@@MoritzKlein0 thank you so much!
how scalable is this? could i make it a 6 channel mixer by just adding more inputs?
great track!
hey, thanks for enlighting us. you mention in the video, that you will occure the panning topic in an other video. did you so far? or do you know a good reference, that is easy to understand/read about panning / voltage controlled panning circuits? thank you
Am I able to use a TL074 for this instead of 2) TL072’s? I am still very new to this and any help is appreciated. I really enjoyed the video and explanations, so thank you. Subscribed and looking forward for more🤙
yup, TL074 will work just fine!
Thank you for letting me know.
Hi! I used to use the TL072 in my own pedal designs, very nice opam :D you can alsp use other diodes, like LEDs or germanium if you find them, to change the kind of effect you get from the clipping stage. Thanks for this amazing video 😀
hey, am I confused or this mixer provides signals more than 10v peak to peak? (at least before the soft cliping)
it does, because it’s adding the signals, not averaging them. so it’s up to the user to set the levels to avoid hard clipping.
Absolutely brilliant for a novice like me...so well explained👍😃
That intro song 🧠🔥🔥🔥
Hi Moritz! Mega videos, ich bin relativ frisch in dem ganzen Synthie spiel und erinnere mit deinem Videos gleichzeitig meinen Großvater, der mich schon in jungen Jahren als ehemaliger Physiklehrer an Schaltungen und Elektronik herangeführt hat. Dafür schonmal ein riesiges Dankeschön!
Nun zu meiner Frage: planst du, in nächster Zeit nochmal ein follow up zu diesem Video zu machen? Besonders mit Kompressor + Sidechain wäre mein Interesse riesengroß!
Viele Grüße
Ben
kein direktes follow-up video, aber kompressor + side chaining findest du hier: ruclips.net/video/Wag-yTyAxPA/видео.html
@@MoritzKlein0 Hi Moritz! Vielen dank! eine weitere Frage hätte ich noch: wie würdest du kompressor und sidechain integrieren? Pro kanal in und umschaltbar, oder einen dedizierten kanal dafür durch den man das routet oder hinter den mix als output?..
Finally I get how diode clipping works! Thank you 🙂
i have two questions. what is the Vcc you are using to power the op-amps and can this circuit be powered by a 9v battery
in the video i‘m using a split 12V/0V/-12V power supply, but you can also use 9V batteries. you‘ll need two to create a fake 9V/0V/-9V supply - check my VCO series for an explanation on how that works.
i have a little question, does the signal get at half the volume when one of the channels is sitting at 0 if i dont have an opamp after? thats because i think for me it migh be easier to just go to an audio interface and amplify the signal there
Perfect Thank you again.
Great stuff, really informative. How about as one of the advanced features you add VCA control (per circuit in a previous video) rather than/in addition to fader pots? Perhaps also VCA controlled panning. Badass mixer!
Can we replace the 2 x TL072 op-amps with 1 x TL074? I have a couple of those sitting on my shelf. Thanks!
yup, no problem!
I stripboarded this and made a 6 ch version. I couldn't figure out why the distortion was awful until I realized I missed the 100k between the two opamps, doh! Very easy and nice
What voltage for opamp and diode values? Thanks
Wouldn't you want to make the clipped/amplified op-amp input on the inverted output from the input op-amp? Otherwise the "fuzz" output is inverted.
I had a question. If i have 5 inputs with 5v amplitude in phase, for output i have -25v. But i had just +/-15 v in power supply. I think it will have distortion. How to get rid of it?
Thank you! This is easy to follow and understand, definitely gonna make a mixer now
I love your videos n.n they're also an inspiration for me, but I have a question: can you use a lm386 as opamp? I'm having issues with the tl series;---;
What if there is an interference between the channels, i.e., increasing volume on one channel leads to the change of another channel's volume?
Hi, I'm trying to go for the adjustable mixer, skipping the last opamp because I'll use it as an audio mixer and want to save one op amp to make a gain knob.
I'm facing a weird issue. The mixer seems to not working until I remove the connection between Non-inverting input and ground... In this case, it's seems to work fine. Any idea why ?
I mean, it's working so I'm fine with this solution but I would like to understand if there is any reason + wanted to know if it's safe for the components and the circuit ?
I love this! cant wait for the Panning video and using stereo Left and right. this is a mono Mixer right?
yup, this is strictly mono!
This is extremely cool. Do you have a bio? How did you learn and how long have you been doing the music and the circuitry? I'm a junior EE and it's all still pretty daunting but this is very inspiring.
Hi friend. Is it possible to have 3 outputs from this setup ? For line 1 line 2 line 3
can I add a 3rd or 4th input channel without complications?
Yes.
Why a trimmer and not a regular pot?
just because you can also adjust the amount of clipping by dialing down the input volume. i think of the trimmer as a set-and-forget for the *maximum* clipping intensity.
what if i have 3 inputs and 3 outputs all inputs going to every output but each output individually controls the inputs volume without signal interference?
Man your videos are fantastic! Thank you for making this. I've been wanting to make a Pocket Operator Output Mixer for a while now. Might have to give this a try.
Really looking forward to your stereo mixer discussion.
You earned a Patreon subscription from me. Nice work 👍
it's easyer to think of the voltage divider as adding them and then finding the midpoint, (5+1)/2 = 3
it's even algebraically equal
(5-1)/2 + 1
5/2 - 1/2 + 1
5/2 + 1/2
(5+1)/2
I tink that what Is in the circuit Is more an hard clipping circuit with variabile treshold, am i correct? If you have time can you treat soft clipping and saturation? i Always dreamed to emulate tape sat with diodes in some way...
Good job anyway
*copied from above as someone asked a similar question:* clipping is considered to be "hard" when the signal is strictly cut off at the clipping threshold, producing flat peaks with sharp angles. this sounds really harsh and digital, for lack of a better word. on the other hand, clipping is considered to be "soft" when the signal can slightly push past the clipping threshold and the peaks are rounded. this sounds warm and analog.
since diodes open up gradually as the voltage applied to them increases, my design produces rounded peaks as there is no hard clipping threshold. (still, if you really crank the volume of the signal going into the clipping stage, the effect will get less and less "soft".) check it in the simulator: tinyurl.com/y4tvpuzl
Hey Moritz, even rewatching your explanations of how these circuits work, I feel like I'm still missing something that'll help me understand it. Try as I might I've never "got" how circuits actually do what they do. Any recommendations for books or online series to watch to really learn it from the bottom up?
did you watch my DIY VCO series of videos? i feel like i went much slower and used easier analogies there, maybe it's worth a try. other than that: i really recommend playing around with a circuit simulator (e.g. www.falstad.com/circuit/circuitjs.html ) - start simple, think about what you want to achieve (passive mixing might be a good starting point), set up a simple circuit and see what happens.
Brilliant explanation thanks.👍