VCO is finished. VCA and ADSR are sitting on my bench. Needed a mixer but didn't want to build the full complexity of the MFOS mixer. Thanks for doing the research and sharing the schematics, this one is on my shortlist now!
Hey Kristian! I really like this video series and have learned a lot. I'm in the process of designing my first PCB using this schematic in EasyEDA. Quick question: Does the R7 120 Ohm resistor just go to ground? I'm asking b/c in the schematic you've got it branching off to P3 GND and then just GND. Is P3 redundant? Thanks again!
Hey! Loving what you do in this serie! I'm probably doing something wrong but I've tried to build this unit twice but both times I have some strange GND issues and buzz. Might the schematic be wrong? P3 doesn't exist so R7 120 Ohm is simply going to ground right? And R8 isn't connected to ground right? Do you have any clue? Thank you!
Hi Kristian, as First think, thank you so much for your contents 🙏. So i assembled a version of buffered mixer with 5 input and one output (1 tl074 + 1 tl072). Like you i used 10k potenziometer on output feedback. Mainly modul works, but that pot works only in a strict range (over that range no sound) and also signal Is not more clear. Do you know what can be the problem? Thank you in advance
I'll try all this out on a breadboard but: TL074 Pin 13 goes to trimpot pin 1? TL074 Pin 14 goes to both trimpot pin 2 AND the output jack? Trimpot pin 3 goes to GND? I think I'll be using a 10k pot rather than a trimpot though. BTW Excellent work, I'm using loads of your stuff and as a total noob it's SO useful.
just done a 5 channel one of these, using a TL074 + a TL072. Next I'll be doing the same with log pots and mute switches. Adding a cap on each input and in each feedback loop. This seems to isolate the channels a bit better. No idea why, I just copied it from MFOS!
I'm surprised about this idea of a buffered mixer... I understand the concept behind it, it's like a buffeered mult as well.. the idea is to not let any of the input signals interfere with each other... what surprises me is, I've looked at various mixer scehmatics from multiple eurorack manufacturers that sell their mixers commercially and they all use the "unbuffered" type of circuitry... i wonder how come?
I've noticed the same thing, I think that they sell the unbuffered circuit because maybe they have in mind that mixers will be used with already output-buffered modules, so there's no need to think about interferences between modules. I have two diy vcos in my modular system (3340 and 8038) and they are not output-buffered, I had the LMNC (unbuffered) mixer for a while, but it did not work properly because signals were interfering, so I turned it into the Kristian's version of the buffered mixer and now it's perfect, I can finally mix the waveforms without problems
great video, I'm going to try to implement something similar to mix magnetic pickups from a hammond organ tone wheel generator. For a use case such as that, would it make sense to use different resistor values since the current from the magnetic pickups are probably much lower than the VCOs?
4 года назад
Id say you would have to experiment with that. Just build one channel on a breadboard and make sure it amplifies the pickups enough.
hello, i have a question about inverter and non inverter opamp enter , why do you put in the non inverter in at the begining and in the inverter in at the last stage please
like this it's an inverter output ?, because i have some little problem with this mixer, and i searching and testing for some solutions thanks a lot bye
Hi, Kristian! thanks for all your videos. Great inspiration!! I´ve built some of this modules! Would this mixer and the unbuffered work with just 9v and gnd? or i would have to make a virtual gnd for VEE?
4 года назад
You need to use a single rail opamp like the lm358/lm324 then 9v and gnd will work. No need for a virtual gnd.
why do you want both in your rig? seems like buffered would always be better?
5 лет назад
Yeah. But listening to “the masses” in the synth diy fb group they said it was a waste of opamps. :) I don’t know. I am making some more passives right now, but have two buffered aswell in the rig so. Mixers are good to have a bunch of. ;)
Hey. I am just starting my eurorack. This will be very useful. My first module was a 4040 binary counter.
6 лет назад+4
Interesting. What do you use the binary counter as? As a sound source, clock or cv? I am really getting lost in the cmos clocking world. Thinking of all the poly rhythms to create with logic gates and counters. But that has to wait for another week. 😂 Right now I am making modules to just get a sounding modular up and running. Hope to see (and hear) what you can do with yours when built.
hello Kristian, is it a mistake in the schematic ? please, thanks
5 лет назад
I don’t think so. Any specific part you refer to? I might have messed up some resistor value which makes it amplify the signal too much.... I am revisiting my mixer schematics to look at this.
@ my question is about the output of the opamp, it's a inverting output : is normal, a mistake ...? and yes is very loud, the "master pot" is in reality a Gain level. thanks
if i look to some schematic mixer on the web, this one, in the inverter enter and again in the inverter enter to re-inverting the signal : www.elby-designs.com/webtek/cgs/cgs04/cgs04_mix.html and in this one, in the non-inverter enter and again in the non-inverter, for a non inverting signal output : familjenronnberg.se/~niklas/diy/eurorack/mixer/ sorry for my english, i'm french, i hope it's clear, bye
@ A very good price from my POV. What material are they made from?
5 лет назад+1
I dont know the name of it, but it is really flimsy (I will talk about this in the MiaW epilog video). It is a material that is specifically made to make name tags or signs to put on walls, to mark cables or connections in electrical wiring etc etc. So not ideal, but with some tweaks (and LOADS of hotglue) it worked for me... ;)
![BLACK BAG - Official Trailer [HD] - Only in Theaters March 14](http://i.ytimg.com/vi/Du0Xp8WX_7I/mqdefault.jpg)
VCO is finished. VCA and ADSR are sitting on my bench. Needed a mixer but didn't want to build the full complexity of the MFOS mixer. Thanks for doing the research and sharing the schematics, this one is on my shortlist now!
Hey Kristian! I really like this video series and have learned a lot. I'm in the process of designing my first PCB using this schematic in EasyEDA.
Quick question: Does the R7 120 Ohm resistor just go to ground? I'm asking b/c in the schematic you've got it branching off to P3 GND and then just GND. Is P3 redundant? Thanks again!
did you work this one out? My guess is it sort of answers my question. Goes to GND/ pin 3 of the trim pot?
Hey! Loving what you do in this serie! I'm probably doing something wrong but I've tried to build this unit twice but both times I have some strange GND issues and buzz. Might the schematic be wrong? P3 doesn't exist so R7 120 Ohm is simply going to ground right? And R8 isn't connected to ground right? Do you have any clue? Thank you!
Late but... I suspect P3 is the input ground.
Hi Kristian, as First think, thank you so much for your contents 🙏.
So i assembled a version of buffered mixer with 5 input and one output (1 tl074 + 1 tl072). Like you i used 10k potenziometer on output feedback.
Mainly modul works, but that pot works only in a strict range (over that range no sound) and also signal Is not more clear. Do you know what can be the problem? Thank you in advance
what do you use to contact the PCB TO PANEL?
I'll try all this out on a breadboard but:
TL074 Pin 13 goes to trimpot pin 1?
TL074 Pin 14 goes to both trimpot pin 2 AND the output jack?
Trimpot pin 3 goes to GND?
I think I'll be using a 10k pot rather than a trimpot though.
BTW Excellent work, I'm using loads of your stuff and as a total noob it's SO useful.
just done a 5 channel one of these, using a TL074 + a TL072. Next I'll be doing the same with log pots and mute switches. Adding a cap on each input and in each feedback loop. This seems to isolate the channels a bit better. No idea why, I just copied it from MFOS!
I'm surprised about this idea of a buffered mixer... I understand the concept behind it, it's like a buffeered mult as well.. the idea is to not let any of the input signals interfere with each other... what surprises me is, I've looked at various mixer scehmatics from multiple eurorack manufacturers that sell their mixers commercially and they all use the "unbuffered" type of circuitry...
i wonder how come?
I've noticed the same thing, I think that they sell the unbuffered circuit because maybe they have in mind that mixers will be used with already output-buffered modules, so there's no need to think about interferences between modules.
I have two diy vcos in my modular system (3340 and 8038) and they are not output-buffered, I had the LMNC (unbuffered) mixer for a while, but it did not work properly because signals were interfering, so I turned it into the Kristian's version of the buffered mixer and now it's perfect, I can finally mix the waveforms without problems
@@RobMurru that’s a very good point!
great video, I'm going to try to implement something similar to mix magnetic pickups from a hammond organ tone wheel generator. For a use case such as that, would it make sense to use different resistor values since the current from the magnetic pickups are probably much lower than the VCOs?
Id say you would have to experiment with that. Just build one channel on a breadboard and make sure it amplifies the pickups enough.
@ thx
@ makes sense. I tried one on a breadboard but have no signal at all. is it possible that it does not work with extremely low current pickups?
hello, i have a question about inverter and non inverter opamp enter , why do you put in the non inverter in at the begining and in the inverter in at the last stage please
like this it's an inverter output ?, because i have some little problem with this mixer, and i searching and testing for some solutions
thanks a lot
bye
Hi, Kristian! thanks for all your videos. Great inspiration!! I´ve built some of this modules! Would this mixer and the unbuffered work with just 9v and gnd? or i would have to make a virtual gnd for VEE?
You need to use a single rail opamp like the lm358/lm324 then 9v and gnd will work. No need for a virtual gnd.
@ thanksss! I Will try this later!
why do you want both in your rig? seems like buffered would always be better?
Yeah. But listening to “the masses” in the synth diy fb group they said it was a waste of opamps. :) I don’t know. I am making some more passives right now, but have two buffered aswell in the rig so. Mixers are good to have a bunch of. ;)
Hey. I am just starting my eurorack. This will be very useful.
My first module was a 4040 binary counter.
Interesting. What do you use the binary counter as? As a sound source, clock or cv? I am really getting lost in the cmos clocking world. Thinking of all the poly rhythms to create with logic gates and counters. But that has to wait for another week. 😂 Right now I am making modules to just get a sounding modular up and running. Hope to see (and hear) what you can do with yours when built.
could you make this with tl072 chips
Yes that should be possible. You need +-12v though to power the chip. So you need to rethink a few places so you keep the gnd and virtual gnd as is.
@ thanks
hello Kristian, is it a mistake in the schematic ? please, thanks
I don’t think so. Any specific part you refer to? I might have messed up some resistor value which makes it amplify the signal too much.... I am revisiting my mixer schematics to look at this.
@ my question is about the output of the opamp, it's a inverting output : is normal, a mistake ...? and yes is very loud, the "master pot" is in reality a Gain level.
thanks
if i look to some schematic mixer on the web, this one, in the inverter enter and again in the inverter enter to re-inverting the signal : www.elby-designs.com/webtek/cgs/cgs04/cgs04_mix.html
and in this one, in the non-inverter enter and again in the non-inverter, for a non inverting signal output :
familjenronnberg.se/~niklas/diy/eurorack/mixer/
sorry for my english, i'm french, i hope it's clear, bye
What is the purpose of the trimpot?
The total gain of the final stage of the mixer. You can if you want put it as a pot on the panel as the “master” pot.
@ Ah! Thanks Kristian.
does this behave like an attenuator? dont want to fry my audio interface
Excellent video
Thank you very much!
How do you make your panels?
I make PDFs of the SVG files and I send them to a lasercutting firm which makes them for 2$ per panel. So quite a good price.
@ A very good price from my POV. What material are they made from?
I dont know the name of it, but it is really flimsy (I will talk about this in the MiaW epilog video). It is a material that is specifically made to make name tags or signs to put on walls, to mark cables or connections in electrical wiring etc etc. So not ideal, but with some tweaks (and LOADS of hotglue) it worked for me... ;)