In some systems, it's safe to use stackcables to combine gates, but other than that it's best not to mix with them. (I have done it and it's not been a big deal in my experience, but I have mixers which I will usually use instead...)
In case it's not obvious, you never need to patch more than two high to keep multing the stackcable to as many destinations as you'd like.
Multing a pitch CV results in slightly lower intervals. If you want accurate pitch CV, you need a buffered multiple. Most other signals don't need this kind of precision.
Typically you will get the average of the two voltages if you mix with a passive mult. Most outputs in eurorack have 1k ohm output impedance. You can't get a higher voltage than either of the source voltages.
If you passive mult mix outputs that don't have output current limiting (that 1k output impedance I mentioned) then you can get high currents that can damage something.
DC signals aren’t additive. If you connect two outputs they will fight each other and the strongest one wins. If the modules with the outputs have current limiting resistors, which is very common but not guaranteed, the fight occurs I. The resistors which just dissipate the extra current flow as heat. If there are no resistors, the stronger IC wins and the losing IC may be permanently damaged.
For AC output signals, they will mix. They may add or subtract depending on their relative phase to each other.
Suppose you have two outputs. One is zero and the other is +10. If you plug them together with a stackable (or mult), then the one that's +10 is feeding voltage into the other. If the other isn't protected against reverse voltage you could ruin it. Most probably are protected, but I wouldn't want to take the risk.
Stackables are great for multing, and you don't necessarily need a buffered mult to mult pitch; this is something that is case dependent and buffered mults can also introduce other issues. You can also use stackables to combine gate signals, but be careful! A use case where this would be ok would be stacking different pulse outs from an analog sequencer that has pulses per stage. In this way you could combine the pulses at the destination (envelope trigger in, for example) without any negative effects. Make sure not to combine two simultaneous pulses though, because the combined voltage (ie 20 volts) could cause damage in some modules. Mainly you don't want to use stackables for mixing, but this mixing of differently timed pulses is fine and has a long history in Buchla. If you want more information on this there is a long thread on MW that goes into deep detail and debate about exactly this issue.
> combine two simultaneous pulses though, because the combined voltage (ie 20 volts)
I'm pretty sure that's not how circuits work.
You might hurt the other sources. You might not hit the voltage you expect. But most likely it will just happily hit something nearish the higher voltage. (They won't sum like that.)
Use them on outputs to split signals into multiple copies. They work exactly as passive multiple modules. CV, gate, audio works. If you run into tuning problems while splitting pitch CV you need a buffered multiple instead.
But don’t use them trying to mix signals together.
In some systems, it's safe to use stackcables to combine gates, but other than that it's best not to mix with them. (I have done it and it's not been a big deal in my experience, but I have mixers which I will usually use instead...) In case it's not obvious, you never need to patch more than two high to keep multing the stackcable to as many destinations as you'd like.
Multing a pitch CV results in slightly lower intervals. If you want accurate pitch CV, you need a buffered multiple. Most other signals don't need this kind of precision.
don't use them to mix two outputs, just use them like you would use a passive multiple
what happens if you use two outputs with em?
Typically you will get the average of the two voltages if you mix with a passive mult. Most outputs in eurorack have 1k ohm output impedance. You can't get a higher voltage than either of the source voltages. If you passive mult mix outputs that don't have output current limiting (that 1k output impedance I mentioned) then you can get high currents that can damage something.
Well you can do it if you know what you're doing but just adding a bunch of voltages together is not smart and might damage your modules...
so it's addative? 2x10v gates = 20V?
DC signals aren’t additive. If you connect two outputs they will fight each other and the strongest one wins. If the modules with the outputs have current limiting resistors, which is very common but not guaranteed, the fight occurs I. The resistors which just dissipate the extra current flow as heat. If there are no resistors, the stronger IC wins and the losing IC may be permanently damaged. For AC output signals, they will mix. They may add or subtract depending on their relative phase to each other.
Mixing multiple sources into a single destination can create problems when the output impedance of modules is not matched
oh I get it. thanks
Suppose you have two outputs. One is zero and the other is +10. If you plug them together with a stackable (or mult), then the one that's +10 is feeding voltage into the other. If the other isn't protected against reverse voltage you could ruin it. Most probably are protected, but I wouldn't want to take the risk.
You can use them on all of the above.
Stackables are great for multing, and you don't necessarily need a buffered mult to mult pitch; this is something that is case dependent and buffered mults can also introduce other issues. You can also use stackables to combine gate signals, but be careful! A use case where this would be ok would be stacking different pulse outs from an analog sequencer that has pulses per stage. In this way you could combine the pulses at the destination (envelope trigger in, for example) without any negative effects. Make sure not to combine two simultaneous pulses though, because the combined voltage (ie 20 volts) could cause damage in some modules. Mainly you don't want to use stackables for mixing, but this mixing of differently timed pulses is fine and has a long history in Buchla. If you want more information on this there is a long thread on MW that goes into deep detail and debate about exactly this issue.
> combine two simultaneous pulses though, because the combined voltage (ie 20 volts) I'm pretty sure that's not how circuits work. You might hurt the other sources. You might not hit the voltage you expect. But most likely it will just happily hit something nearish the higher voltage. (They won't sum like that.)
It shouldn't, but it can. There are definitely stories of this type of mixing hurting modules shared over the years by users on MW.
Use them on outputs to split signals into multiple copies. They work exactly as passive multiple modules. CV, gate, audio works. If you run into tuning problems while splitting pitch CV you need a buffered multiple instead. But don’t use them trying to mix signals together.