System 55 Mixers - Active and Passive

[@theedxqboi]

I enjoy your videos. Just got a System 35, will be getting a 55 hopefully soon, and expanding it with the Bode Filter, another low pass or two, as well as another sequencer.

[@ozhalljr]

Thanks! So will you keep both the 35 & the 55? That would be monster system!

[@monodux]

Great stuff O.Z.! I really love the system 55 design for this reason- it is modular enough you can make almost anything you need, one way or another.

[@ozhalljr]

Thanks!

[@attorks]

Thanks for the video. Good explanations. I personally would not mix using multiples because it also influences the source of the inputs. I only use multiples with 1 input and 2 or 3 outputs. But it can be done as you showed.

[@ozhalljr]

@attorks Thanks of leaving a comment. I'm a fan of your music. I don't often do passive mixing, but it is another technique in the bag of synth tricks. Passive mixing came to my attention as I researched the original ARP 2500 for the videos I did about a year ago. The ARP 2500 patching matrix allows you route from multiple outputs of other modules to a single input. One example is patching different oscillators or waveforms into a filter audio input.

[@ozhalljr]

For anyone reading this. @attorks (Martin Peters). Taught me how to do Berlin School sequencing!

[@moogfooger]

terrific video. Thanks for all the great analysis! I was wondering if you have any experience with the Behringer Brains module? It looks very interesting. Not a classic synth by any means but a different voice option.

[@ozhalljr]

Tony - thanks for the kind review. I have not played with the Brains. It seems similar to the Braids/Plaits. Since I own a Plaits, I'm a little more interested in the Abacus.

[@moogfooger]

yes I can understand if you have plaits. but abacus would be a lot of fun. lots of interesting gate options. let us know if you get one! cheers@@ozhalljr

[@ozhalljr]

@@moogfoogerwill do.

[@livelooper]

A mult can only work as a mixer if the devices that are input to it are specially designed to work with that configuration. This isn't usually the case.

[@ozhalljr]

Yes, there are limitations. What audio signals in a system 55 would not work?

[@__teles__]

@@ozhalljr Since the Moog design doesn't have level controls on active outputs, there is little use for stuffing several outputs into an input.

[@ozhalljr]

Maybe I'm misunderstanding your point. To me clear, I don't often do passive mixing, but it is a technique in the bag of tricks. If I want a "composite" waveform that combined two waveforms from an oscillator, I could use an active mixer. If I wanted to conserve my active mixers, I could use a mult. I could use an attenuator (or two) to change the mix of the two waveforms (which changes the underlying premise that the Moog design does not have level controls on active outputs). One side effect is that the resulting waveform would never be of greater amplitude than the waveform with the highest level. I might want this side effect. Am I missing a point that you're making?

[@livelooper]

@@ozhalljr . I've only heard of moog grandmother being designed so that passive mults can be used as an audio mixer. Maybe sys 55 has that, and maybe the Behringer equivalent does. Generally the rule is don't connect output to output ever. So generally in Eurorack this is not something you'd do. Re: the Behringer, I have the multiband filter, which is great, but note the 2 inputs are just in parallel {i.e passive mult}.....that would support the idea that other sys 55 modules are designed with extra components on the outputs so you can use passive mult as a mixer......but the Behringer 55 stuff is Eurorack and I've never seen them mention that those inputs shouldn't be used to mix non 55 signals.

[@ozhalljr]

@@livelooper Thanks for the detailed reply. Generally speaking, the Moog modular modules have been tested in nearly every patching configuration. ( per a history of Moog that i read ... perhaps "Analog Days" ).

[@returnofthenative]

Who's,a,clever,boy,then? Thank,you,very,much,Sir....W.Aust.

[@ozhalljr]

Thanks!

[@aemilpeters5644]

Time for a little update / modification on your video seems warranted (I can ssuggest): kzbin.info/www/bejne/d2iVYZudmapna68 (your Sytem 55 UNboxing also got updated; KZbin informed me, very rescently): kzbin.info/www/bejne/d2iVYZudmapna68

[@aemilpeters5644]

kzbin.info/www/bejne/n2ekmWeKmpiLd80

[@ozhalljr]

Finally got around to updating the Description with a disclaimer. thx.

[@ozhalljr]

Really interesting technique. @sarahbellereid does a lot of those videos.

[@aemilpeters5644]

@@ozhalljr Still the content in this mixer video on the System 55 (S 55) is at certain sections fundamentally and unwantedly & permanently in error. You still have several options including - for now - removing it form your otherwise interesting depositions here. How to proceed? A) Deepening 101 electronics theory course (not hands on) could calm down the need for overresponding with even more postings here. B) DIY passive and active resistors building based on calculated resistor values, etc. C) Have a serious sit down one - on - one with a graduate in electrical engineering, a note pad and pencil and re-understand the 101 course. D) Get an additional row or Euro rack space with some more REAL Dr. Moog designed mixers by e.g. Behringer, etc., and explain that you never can have enough of these.......MIXERS! And/or, add to your otherwise interesting video on the major missing aspects of the S 55 synth: a missing mixer with many more inputs or routing options than the old original that served all major needs in the past but modulars tend to get larger that last 50 years - hence see also my remark + a you tube vid from your friend - see blow - re the application of a matrix mixer!

[@aemilpeters5644]

Or, go an additional step forward and introduce the next level of modular mixing: kzbin.info/www/bejne/r56uiKNojMiGqas

[@aemilpeters5644]

On the attenuators and mixers in 15-35-55 styled models/modules: kzbin.info/www/bejne/p3TQfWiFmqeao5o - mixers and multiples are different and are for different purposes by design - your statement to use THESE multiples as stand alone devices (even with some extra potentiometers) to be used as passive mixers as displayed here is VERY incorrect Mister Hall, reconsider your section on "multiples" here in your video - THX for your consideration: kzbin.info/www/bejne/p3TQfWiFmqeao5o

[@aemilpeters5644]

kzbin.info/www/bejne/i6Omd6lopqh4gqs - some theory.

[@aemilpeters5644]

kzbin.info/www/bejne/p2nXnoidlr2le7M

[@aemilpeters5644]

kzbin.info/www/bejne/rYm2k3Spech7qas

[@aemilpeters5644]

kzbin.info/www/bejne/hKKyg2SKrtJmnJo

[@aemilpeters5644]

kzbin.info/www/bejne/mXmte6hjna9_pac

[@aemilpeters5644]

Your speak: kzbin.info/www/bejne/m6jaoYONd5aJhcU - "a multiple can be used as a passive mixer": that is technically not correct and also as such not intended in general electronics. If you want to passively mix you better get a real resistor passive mixer and NOT just have two output stages of e.g. a Bode shifter and an Dr. Moog design oscillators' output stages feed into each-other via a multiple and then feed in to the input of e.g a filter - that is not the idea / how things are done professionally - there are VERY unwanted side effects that you may never knew (since you can not A/B wrongly connected devices) and also you can NOT replicate such setup with an other spectral content. These output stages are simply not designed to operate that way! That your synth keeps operating does not mean (you can not A/B) does not mean that it will work for low or high(er) frequencies or even dynamically (or very Bass rich sounds - they may cancel out). More often than not you also will adversely & negatively affect the signal - to - noise ratio in a large setup, hence eliminating expensive electronic design and technical progress in general - a waste. This (your) way of how you plug and play, and talk; AND you write in the header above: "I'll also show how to create a passive mixers with a multiple." This is NOT the right way to explain & technically incorrect. You better revisit your texts/imagery her and expand into distributors (a passive multiple) and passive attenuators and real (active) mixers and (external or euro rack passive mixers) (often used with mixers with only one aux send to /stereo return) to drive e.g four or five different effects pedals, etc., in general destinations. Often called summing passive mixers as seen in PRO studios to mix a few dozen or so effect returns in 2 new outputs without any noise or power consumption into a stereo effects return on the master-bus. Passive resistor mixers are very simple devices that often are used - in analogy here with oscillators to feed into 1 filter, as example if you run out of active mixers. Better in your situation to add a Dr. Moog 4 into 1 active mixer and mixer as intended: a low output impedance sound source into a high impedance input device (a filter input). Passive attenuators are also often used in a backwards way if summed and used as mixer but even that requires extra resistors in addition to the attenuation potentiometer(s). You have to LARGELY expand here on DC coupled active audio mixers that also can mix Control Voltages vs passive multiples (distributors) vs active AC coupled mixers vs summing audio only (often AC coupled or assumed AC fed and AC sending/receiving) or summing DC mixers ((with or without DC shifters (or a variable offset) often used for wave-shaping of oscillators)) or active mixers (with additional positive or negative gain if needed), etc. You cut yourself short - and therefore your public and shortcutting outputs of pricey euro-rack modules - my main concern here is that a passive multiple (a piece of wire) is a distributor to send 1 voltage or signal to 2, 3 or many more destinations and not a device to blend output stages of pricey active devices, hundreds of $ or euros that need a formal input stage often 100 to 1000 times (or even more) in impedance (and not zero or 1, 10 or 50 ohms or 1000 ohms serie output resistor / impedance of another output stage or stages) - to operate correctly - over the frequency range for which they were designed. You overextended your enthusiasm for economic and practical solutions that often (or only in the equipment you displayed) may (partially faulty) operate but doesn't result in replicable results over time, device manufacturer or type of device but are potentially consumed by you pubic as a truth. If learned as such on a modular synth (which is considered useful for any recording, mix or sound engineer, or synth player in general) and later used with high power guitar amps, lighting systems, computer interfaces, or what not....: adverse effects may occur. HAVE A LOOK AT PASSIVE RESISTOR MIXERS as stand alone solutions - often there is a volume knob that you can use - they also can be used backwards and become a resistor based distributors and then the knobs can act as modulation depth - draw some wiring schematics and see how it works - CHEAP!

[@ozhalljr]

Thx

[@aemilpeters5644]

​@@ozhalljr STOP-STOP-STOP: even here you can see on your 'scope’: kzbin.info/www/bejne/m6jaoYONd5aJhcU that the feeding signals by the upper 2 waveforms are diminished in amplitude and altered in wave shape as a result of your mixing efforts - an indication of wrongfully loads on the outputs of the oscillator - see for yourself 10-20% of the amplitude is GONE in upper chanel and the mid channel shows a DC shift AND massively altered waveforms. The inherited residual (your ‘mixing’) shows NO amplitude increase for reasons that are very different than your reasoning - that is an effect of ‘non-DC’ but only ‘AC-coupling’ somewhere in your mix an/or measurement chain (and similar frequencies but from an opposite polarity) cancel out - since you drive the waveforms form one and the same oscillator providing these waveforms hence - in this case - the same frequency - additionally the fast fourier transformation - frequency - analysis would have show a very modified spectral content and thus a loss of musical information. Moreover, the original waveforms (upper and mid channels are mutated, lower in volume, shifted DC levels and show ALL signs of electrical wrong functioning, overload, distorsion, and potentially exhaustion in the output stages of the oscillators themselves due to abnormal loads and usage causing electrical malfunctioning in the oscillator (resulting in altered waveforms that you intended to mix) and therefore causing non-replicable results and (potentially) shortened longevity of the modules, drift in tuning and more heat dispensation in the components of the output stages of the device itself. You do NOT want that the original feeding waveforms (which also may be used elsewhere in the modulation or signal paths) have been altered - these were carefully designed (by Dr. Moog) due to massively mismatching of the very use and application of a multiple (a passive distributor and not a mixer a all): kzbin.info/www/bejne/m6jaoYONd5aJhcU - your display - at least the pertaining section of your video here, does NOT explain anything other than yours’ gross misunderstanding of elementary electric theory, unusual application of visual material (“scope”) and the potentially misinforming - while you keep up your video here - of your public. You can do better and improve of the otherwise - at some sections - nice video here by understanding and building DC coupled or AC coupled passive resistor (including the pots or variable resistors) mixers yourself for under 05 (five) dollars in component cost and finally start the 101 - 909 electrical courses in order to inform others - the old Radio Shack booklets would have been TOTALLY explanatory in this regard for you and your helpers (if any) - check your local library, a Greensheet/2nd hand booklet store, Internet 2nd hand outlets 2nd hand markets for some copies. In addition you could benefit to be informed about active and passive distribution of signals by studying distribution amplifiers (e.g. for headphone mixers) or how to connect 1 aux send of your mixer to e.g ½ a dozen delay and filter and echo pedals/euro-rack units and subsequently mixing these in a passive resistor (summing) mixer or active summing mixers - either AC or DC coupled depending on the need or availability of either type and the AC or DC coupled output stages of the connected devices - good luck with your findings - eventually your public may benefit from it! Wanne mix (with)in transformers or with speakers, mics and live sound mixers too and add spectral content - that is also an option?!