Getting into Modular with the Behringer 110 PART 2 

Hi Tim. Great video. You did a nice job of explaining the limitations of splitting. I am an electrical/electronics engineer, and I can explain what you demonstrated in a little more detail. Everyone is on the right track. This all about OUTPUT current and INPUT impedance. Each module output CV has voltage (obviously), but the output current supply is the more important aspect when it comes to splitting. When you take a single CV output, and split it, you are creating a parallel circuit (in electrical terms), which provides the same voltage, but divides the current. When you split the CV into two CV outputs, unbuffered, and send them the the input of a VCO, we are now concerned with the input impedance (resistance) of the VCO input (opamp input). Impedance is a large topic in itself, but we can think of it as resistance, which is the amount of current that the input will 'consume' in order to function correctly. A VCO will have a minimum input current to be able to operate. In a 'perfect' world, all inputs would have extremely high impedance, so the amount of current they consume would be very little, but the reality of course is that they do consume a small amount of current. When you plugged and unplugged the inputs, you heard the difference. Since there is some input impedance (also known as the 'load'), and a small amount of current being consumed, there is a resultant VOLTAGE DROP across the input impedance of the VCO. This voltage drop will cause a drop in VCO input voltage, and therefor the pitch. So when we split a CV into multiple VCO inputs, we are dividing the current (reducing the available current to each input), and then seeing that smaller amount of current causing a voltage drop across the input impedance of the VCO. So there are few factors to consider when splitting CVs, or any signal for that matter. First, you want to have a buffered output so that the 'available' output current is high, so that when it is split it is still sufficient to drive the input of the VCOs, etc. Some eurorack modules have good output current characteristics already, so can be split without impacting the signal too much. The second factor is the equipment to which you are providing the split signal. If the module is good, like a high end module, the input impedance will be high, the current consumption will therefor be lower, and the voltage drop on the input will be minimal. The best way to overcome the splitting issue is to do what you suggested by having a buffered output. This is not about voltage, but current. A buffered output has a higher current supply, so that when the signal is split into parallel voltage paths, there will be no appreciable drop in voltage across the input impedance. If electrical specs are available for a module, look for the module with the highest output current, and lowest input impedance. I haven't compared specs on a Moog vs. Behringer, for example, but I bet there will be a difference.

Tim, for the last couple of days you have moved into my living room with your excellent modular tutorials. Not only do you explain things clearly but you also provide highly enjoyable sonic examples and MUSIC!! Thanks for that.

Fundamentally, another great video.

Most outputs will have 1k output resistance. Most inputs will have 100k input resistance. So rule of thumb is basically "each multiple will drop signal by around 1%" That is not a standard tho, there are modules with different input and output resistance so you never know unless you check the specs of the module. So another rule of thumb would be "if you care about exact pitch, use active multipler, for any other signal passive one will almost always be enough"

Terrific video. What really made me happy is the fact that the solution to the CV splitting issue is already in my rack, as I collected all system 100 modules. Till now I wasn't completely aware of how useful the 297 module really is.

Love the informative, personal, and relaxed delivery of your vids. Great for relaxing and synth dreaming. Thanks for all the things you do sir. 😊

Really appreciating these videos Tim, I’ve been considering getting into Eurorack via these modules and it’s given me lots to think about

At 34:00 the bass line slowly evolved into Nena’s “99 Red Balloons”. I loved that bass sound as a teenager. 🎈🎈🎈🎈🎈🎈🎈🎈🎈×11

Love these videos! As for me, planning on getting a modular, this information is gold... The Auld Lang Syne-piece at the end. Beautiful... It's brilliant that you in your videos are showing the real potential of these synths, by using your music that is composed, arranged and played beautifully.

Tim, Great presentation. In an attempt to answer your question, the pitch issue can be explained by looking at the Moog CV standard. Under the Moog system, pitch is regulated on a scale of 1 volt-per-octave. So for every octave on the keyboard, the voltage increases (or decreases) by one volt. If you wanted to, you could attach a voltmeter to the CV out of any module and measure the voltage. When calibrating a module, you can take a measurement at the baseline and then another measurement an octave higher. The difference should equal one volt. However, If a cable is too long, or if it splits the signal multiple times, the voltage at the other end will be lower than 1 volt, due to the resistance in the wire. the result would be a difference of something less than one octave, otherwise known as “out of tune”. Buffered, or powered multiples solve this problem by ensuring the voltage from the various jacks remain consistent. The other issue is the sound module itself. Some oscillators have a stable pitch over only an octave or two, while others maintain stability over several octaves. This is due to the quality of the components from which the module was built. Again, the solution is in the careful calibration of the module. The only other caveat is that most analog modules are never perfectly stable. That instability is what we have come to recognize as “character”. As you know, some modern synths have a knob to allow you to destabilize the tuning to emulate the sound on an older machine. One man’s pitch problem becomes another man’s vibe! Hopefully that helps. Thanks again for your informative series.

This.Right.Here…is really valuable information. Especially when considering pitch issues and CV. Thanks Tim!

Happy New Year, Tim! Thanks loads for yet another great video on these modules! When they become available again (whenever that might be for us poor, isolated, insular Brits...) I will get what I can! Converted!

Great video. I don’t think a lot of people realise the importance of utility modules like multiples and mixers. I bought a couple of VCO’s, a filter, etc and then realised I had issues connecting them up with my semi-modular. Luckily I had room in my case for a buffered mult and a mixer. On the topic of semi-modular, it would be nice to see a video on how you might use something like the Crave or Mother 32 or Minibrute 2 in combination with modular gear. It could save people a few pounds and make getting into modular a little easier. I’m thinking of buying the Crave because you get so much for the money. Really enjoying the channel. Thank you.

Loads of useful information without the usual pribble-prabble. Very pleasant.

I'm using two Rides in the Storm QAM active multiples for CV signals that need stay in tune. They are like 58 euro in Thomman. Compact, and with a little clever feature that I love. It sports 4 imputs with 3 outputs each. A and B are normalled together, C and D too. For instance, if you patch a cable in A, but no in B, you get 6 outputs.

Thanks for all the sound advice here. Practical and informative. RU-vid needs more real content like this Tim. The B 297 is an enigmatic module to the uninitiated. A video on that module would be a great boost. There are no other in-depth vids of this anywhere that I have seen. Cheers

U can Split a trigger or mod Signal with no Problem, since the voltage Drop is neglectable. Only for exact pitches this is an issue

Great video! I've learned a lot from this and part 1. Now I know what better to do with a synth on an init preset. The Roland SE-02 is probably one of the odd duck 3 oscillator monosynths. I'm still on the fence about getting into Eurorack but am glad to be learning. Cheers.

Surpised the erica cv output could not drive the three vcos, and buffering with a unity gain op amp is the way to go, as you neatly demonstrated. An active multi would also do the job, like the Intellijel Buff Mult. Using an audio mixer to do the job may not be as stable/accurate on pitch, depends what op amp is inside.

In the audio world we used to call them "line drivers", "distribution amps" and "summing amps"

Tim, Loved these system 100 vids, well done and you convinced me that its the way into my first modular, buy button hit on a bundle plus 182 sequencer, cheers for these very informative blocks of entertainment.

I'm glad to hear about things not blowing up. I've always wondered about potential problems with connecting CV to/from Audio.

They look really nice in these small doepfer racks

By the way groove you created is freaking awesome. Good stuff bro!!!

Thank you, I learned some very usefull tips!

Wow. This was a deep dive compared to the first part, Tim. Always touched by your music. So lovely. Thx for this helpful insights and a healthy 2021!

Thank you so much for this series. Your videos are generally among the best I‘ve seen, and in particular your modular tutorials are THE best! Also the mixture of explanation, recommendation/comparison and sound demos is perfect to „digest“. There‘s just now a problem: I got infected by the modular virus...

Super educational and fun music! Thank you!

15:27 I'm not surprised with CV getting pulled down. It's down to the design of the MIDI to CV converter and the design of the inputs. Mullting audio outputs is rarely a problem because most audio inputs draw very little current. 22:40 I'm in the don't do it camp even if it appears to be working because components can be stressed. Good design protects against this but there's no guarantee that good design has occurred. I used to write maintenance manuals to component level and there were several occasions where I sent the draft to the design engineer for technical review and their comment was "I wondered how that bit worked".

Great tips. That voltage processor / summing mixer module is very handy in a tight spot when there's voltage strangling, which was demonstrated so clearly! Also very handy for balancing the relative levels of modulation sources against each other before they go to their destination. I've got a 132 coming for my 100m soon, it was a must-have. Btw - nice module photos at 18:52 they look kind of familiar. ;)

Fantastic videos

Thanks for this video. i learned a lot.

First of all i want to thank you and congratulate you for your really great videos. Now, regarding your question at 20:30 ... it is related to ... physics ( well, isn't it all? hehe ) .... trying to make an oversimplified explanation, i would say that splitting the signal from one output to several inputs using just "splitter cables" is like stacking many resistors in parallel, which stresses the output by requiring more electric current to come out of it and go into the inputs. Every audio output has something called "output impedance" and every input has something called "input impedance" and these have to "match" when connected for the best signal transfer. You can look up terms like "output impedance", "input impedance", "buffer", "ohm's law" and "combining resistors" for more scientific/geeky stuff. What you used for solving this, was effectively creating a buffer/amplifier from that output to those inputs. Correct signal splitter/multiples should really be buffered/amplified to avoid this in modular systems. Thank you again for all your great videos!

excellent video...i use mentioned dreadbox multis both for splitting and mixing..seems working fine

The reason the output signal is dropping slightly, causing a detuned VCO frequency, is that its output signal is being overloaded when being split to too many VCO inputs. The mixer output has a stronger output driver stage and can supply more inputs without the voltage dropping ( More technically, it has a lower output impedance and can supply more load current).

A great video which I found very helpful as I have most of these modules in my new setup, and a very fitting end tune for a Happy New Year! Thanks Tim!

That was why the original Roland 100M system so great, because it had CV and Gate as part of the power bus. The case has a CV and Gate input that you could then use to get CV and Gate to all the relevant modules. CV and gate are also avaialble on the Doeper A-100 bus, so not sure why Behringer did not use this feature for these modules to make use of that.

thank you Tim. I've always been wondering about the active vs passive splitters. you have proved my theory :-)

Thanks for your incredible postings',Tim! Your work is second to none! : )

Assuming Berhinger makes all their modules with the same input impedance. The circuit as you have connected it is 1/3 the resistance of one input. The output has a load 3 times bigger because the resistance is divided by 3 and thus the current is 3 times larger.

Tim, fundamentally speaking, thank you!

Topnotch job Mr.Shoebridge !

Wow, this is super useful, thanks Tim!

I would love to see more modular from you. Encore, please! ;-)

the term you're looking for at about 20:00 is "fanout", the fact that an output is able to feed multiple inputs. it depends on the ability of the output to provide enough current for all of the inputs it is connected to.

THE best Stuff on Sunday, many thx

Very good Tim! Learned a lot from this video yet again. You explained mults which I’ve been confused about as well. Would love to hear more about gates and ways to use them. Also would love to see examples of the Behring synths semi modular with the eurorack. Like the model D or any others you have incorporated with the system. Happy New Year and thanks for another great video on this subject. It’s very digestible and I appreciate the pacing of it.

Happy new year and thanks again❤👍

When using a passive mult, the effect of the voltage decrease is called loading. It happens when the source can't regulate the correct output voltage when the load (destination) changes.

Im an electronic engineer, wiring an output to multiple inputs is called fanout. Given well behaved modules, the input impedance should be measured in hundreds of kilohms, and typically theres no more than 1k of output impedance (usually manually introduced to stop you blowing the output wheb you drop a jack against the panel) using Max power transfer equations, a reasonable max fanout of around 100 is not unreasonable, however each additional load will imperceptiblely attenuate the signal, however they will add up, at a fanout of 100 assuming a 100k input and 1k output the voltage attenuation will be 50% and all your CV will be out of tune ;) That said these are all worst case numbers, in practical modules input impedances are often measured in megaohms, and output impedances of 100ohm is still safe. So its pretty safe to say you do not need to worry about chaining splitters.

Great Video. The 173 Modul has passive Multipliers therefor the Signal from the Erica Module is turned down. Foe example, the Doepfer A-180-3 is a buffered Multiplier.

Thought I'd copy my reply to the main thread to explain signal loss. It's all about output impedance. The lower the output impedance of the supply signal, the less the voltage drop when each following load is added. For simplicity. Let's assume you have a source of 10v with an output impedance of 1kohm. At no load, the voltage will measure 10v across the source. Now if we add a 9k ohm load, the circuit is 10v-1k-9k. There will be 1v drop across the output impedance, giving us 9v at the load. If we add another 9k ohm load the total load is now 4.5k ohm. The voltage drop will be ~1.82v yielding 8.18v across the combined loads. And so on..... So in a nutshell. you want your source to have the lowest possible output impedance, and your loads (inputs) to have the highest possible input impedance. 1 to 100 is ideal, but it's not uncommon to be closer to 1 - 10. www.edn.com/wp-content/uploads/media-1307558-witte-blog01-pwrtransfer-fig1-600x457.png Edit. BTW. It's pretty easy to calculate the output impedance of a device. All you need is an accurate multimeter and a couple of resistors. 10K ohm and 50k ohm. Measure the open circuit voltage at the output, then load it with a 10k resistor and measure the voltage across the resistor. Using ohms law you can calculate the circuit current, then divide the voltage drop (Unloaded voltage - voltage across load resistor) by the current and you get the source impedance.

Another brilliant video! Cheers for the dumbed-down explanation, especially for younger teenage/YA viewers of yours like myself, really helps especially since I often use your videos as tools to educate friends who may not have any electrical experience at all (or at least intend to from now on :p). I know you didn't talk about it much, and it's maybe not the "sexiest" module, but how has your experience been with the 305? Do you think it's an upgrade worth having for someone who's otherwise just plugging module outs directly into an interface or using a small stereo mixer (like the MTM Startup)?

Great stuff Tim. Happy new year.

The problem is that the Erica MIDI to CV module has relatively high impedance output. Another way to look at it is that it is a poor voltage source. The Behringer mixer is acting as a voltage follower with low output impedance.

When is the video coming that covers the 150, the 172, the 297 and the gates in the 173 :)? I also found some really neat tricks you could do using the 182 sequencer like variable tempo from the 2nd channel or using it with audio rate and as a sorts of waveshaper, that could be nice to illustrate!?

A simple way to think about is you would not connect the left and right speaker wires of your stereo together to mix them this would be the same thing.

Great vids. Keep them coming! :)

BTW Tim, have a look at the Endorphin.es "Shuttle Control" module for USB to CV conversion plus a built in Eurorack PSU unit. Probably the best Swiss Army knife in Modular :)

Late to the party, but anyway. tried the "overloading" of the mult using the CV from my Behringer Model-D, and didn't have the problem, so it seems like it provides a stronger signal, just like the mixer on the 297 does.

Since the mixer have a buffered output the op-amp will compansate for the drop in voltage caused by multiplying it. Op-amps are comparing the incomming singnal to the signal being put out. I am not an expert on this, I have just heard Christian Blåsol talk alot about op-amps on his RU-vid series, Modular in a Week, so I have a slight understanding on what they do as I am into mixers. If you use the 182 and hook up all the VCO, it should be possible to make a tuned sequence with a stackable, patchpal mult/star-thingy/0HP-mult or passive mult as it does not rely on volt per octave, but de-tuning the VCO will theoreticly make them stray slightly from each other.

The detune problem is probably simply caused by the resistance of the material (metal...) of the plugs, lowering the voltage of the signal. thanks !

more you stack cables, more current flows from source module .. cause it’s badically parallel circuit, voltage on all connected inputs should be same as soon as source will ve able to “pumo” enough current .. when it will be not anymore, either voltage starts drop (on all connected destinations) down or in worst case you can burn your source module circuit (not much likely but in theory it can happen)

Do you lose voltage or volume or anything when you use a mult cable ??? Oh never mind you wonder the same thing haha. Ok... now im learning more and it does exactly what I thought it would... loses voltage the more you multiply it? Makes perfect sense when you think about it

Does it keep the tone in tune if using another splitter like a stackable? Is it your midi to cv that Erica has a weak amplitude. And can’t bear to transmit to more than one unit the mixer amplifies the signal and there you go!

Hello, I saw that in one of your boxes, you had a 110 and a 150.How best to connect these 2 modules, with a behringer crave ,in order to complete it? Thank you in advance for your answers....!👍😉

Attenuating the CV signal with the 297 will (and did) solve the CV offeset

Happy new year Tim

Happy New Year Tim and thanks for another really interesting video. I have no real interest in modular but enjoy your content so I watch even the modular ones. Whilst I can fully understand the attraction of modular, it just wouldn't suit me as I'm basically lazy and want to press a button and save my patch creations :)

Tim, I like your channel and your music. Don't you find that running both a VCA and a VCF from the same envelope generator is a bit limiting ? Rarely do I do this, preferring to use separate EGs (or other modulation source) for VCA and VCF. My system consists of most of the same Behringer 1xx modules as yours, along with other modules. Also, I believe the Roland (and Behringer) VCFs in this series are 12dB/Octave. I prefer a good old fashioned 24dB/Octave ladder filter (or in my case, SSM2044 based VCF). Cheers. Keep up the good work.

Excellent pad sound at 31:30... I really liked the look of the three-module case in your previous video (and have even gone so far as to cost it out- £375 including the Doepfer case). Aside from the obvious GAS-related difficulty of sticking at just three modules, are there any issues with sound generation that you’ve identified? I guess what I’m trying to ask is whether, with a Keystep 37 and a raft of fx, that would be enough in and of itself- because it’s very attractive.

Enjoying your videos, a big help. The Mults was interesting, maybe you at some point explain the difference between mixers, as an example (using the System 100 modules) the Behringer 305 EQ/Mixer/Output and the Behringer 297 Dual Portamento/CV that you show. I see one is more for sending the final signal to the out/amp/speakers. However, what's the difference between the two (in usage)? Does one need both (ideally), or is one more important than the other, etc. Thanks in advance.

oh I am still far away from the modular world. I have played around with Pure Data trying to make my own monosynth and stuff but kinda got lazy and stopped. currently trying to dig into the "hidden" features of my microkorg S lol but your videos really help getting my head into this

Hi Tim! great video,as usual!have you tried sleepers fh-2 midi to cv?how is it compared to the polyend poly2?

4:10 Happy New Year Tim!

Call me crazy, but wouldn’t it make sense to put a splitter cable in an available vca and put the other end between them?

Regarding the signal degradation problem, it's a shame that Behringer made the mults passive instead of buffered. But since you're multing pitch CV, couldn't you compensate for the pitch offset by individually fine tuning each oscillator?

Even though I’ve been fascinated by the modular world for quite some time, I have never taken the plunge ... but after watching your 3 System 100 videos, I ordered my first module last Friday so errr now my wallet looks nervous 😉 BTW is it just me or are the System 100 modules just really really hard to find in stock anywhere ? Now you know why only one module is being shipped to me... Of course I felt obliged to pay homage to Roland and order their Eurorack case too but guess what, that’s on backorder too. Sheesh.

Tim, if I just bought all the system 100 modules would it be in effect a Roland system 100 and what size eurorack would I need? as no size is mentioned on sites that sell the behringer modules

Hey Time is there a stand alone midi to CV converter? If so what brand? Thank in advance. Oh another great and informative show.

I was wondering if you could answer something for me. Let's say I have a Tiptop Mantis case. Which Behringer modules would I want to make a sort of DFAM-ish device?

Is multiplying a signal the same thing as unison?

I realize your videos are long -- perhaps this leaves you feeling hurried, but please feel free to annunciate your name fully, and clearly -- you deserve that much credit! I really appreciate your efforts.

How about running it off a guitar? Could that be done?

41:20 I know I keep making this same comment on your videos but if anything besides the 960 sequencer is tempting me to start going modular it's the lovely creamy sound of the 100 series.

Hi, Tim, thanks for the great video! I just have a question... What does a modular synth depend on when it comes to polyphony? does it depend on the keyboard for example? If so, do you know if it's possible to controll a modular synth with the Arturia Microfreak (which is a 4 voice synth)? Or, that depends on a specific module? Thanks in advance :c

Sorry, I’m no better off when it comes to the electrical engineering behind what’s going on but I think it’s related to impedance and the load placed on the pitch out CV signal when it’s multed? 🤔 however I’m firmly in the ‘don’t plug an out to an out!’ Camp (I have seen little passive audio mixer circuits but again beyond my level of understanding) anyway, happy new year! Stay safe! lovely tune, sweet arrangement! Here’s my debacle on an old seasonal favourite for your hypno enjoyment: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-83dYct1vm8A.html

Hey Tim is there any advantage to taking the 182 sequencer module vs using a Korg SQ-1?

Flower on the synths??

As some folk on reddit have quite rightly said... if the Behringer mults module is powered then why is the output sockets passive? seems a waste of power for just a few gates.

Great vid, Tim! I have two 110 and am thinking about getting a 112 and use one osc to each of the 110. If patching an 112 osc to the VCF 2 on the 110, will it automatically also go to the VCA?

Could you explain what the other modules are for? Esp. The lower right Modul (Big one) . As space is always a concern...

When will these Eurorack units be available? I feel like it’s been over a year since they started getting announced, but I have never seen them anywhere??

110 luftballons 34:00 -

Which modules would I need to get and Modular SH-101 ? :)

"Auld Lang Syne" a la Kraftwerk? :L Auld Lang Sine-Wave.

Use passive mults, play out of tune music then call it "microtonal" and you suddenly become an experimental artist. :) :p I have to kindly strongly disagree about POLY2, buggy, not supported / developped anymore, poor build quality and terrible choices of design (like impossible to choose a midi channel when in polyphonic mode which is terrible, pitchbending implementation very weird etc) and also very expensive module for what it is. I was very disapointed! I went for Hermod which is a killer interface (much more flexible than Poly2) and adds beautiful sequencing for just a slightly higher price.

First :)

Really don't like that sound. Sounds like tinnitus.