analog synth control voltages?

[???????]

does anyone know what a common range of synth control voltages are?

I'm really curious what would happen if I took the CV out of my moog and ran it through the echoplex, printing the CV to tape and delaying it, and then sending it out to a CV in on my friend's Korg MS-20 to control one or more parameters.

I just don't want to ruin my echoplex in the process.

Any clues?

[A-Barr]

I think it's like 6 volts, you could measure with a multimeter but you may have to output a 60hz. signal, as many multimeters will only measure AC at that freq., or of course have it output dc and measure.

That is a pretty freakin' cool idea you got there, but I wouldn't want to hit anything with 6 volts, especially since the EP probably hits saturation at 1 or 2 volts.

But, you could run the cv through a 6:1 voltage divider to get it to a line level signal, then run that into the EP, take the output from the EP and set it up into a little preamp with a gain of 6, like a 12AU7 or somethin', if you've got the bits and pieces laying around.

[???????]

yeah that's what I was afraid of, 6V is a bit high.

Thanks anyway!

[crow]

I'm pretty sure you know a lot more about this stuff than I do, but why don't you hook up a meter to your moog's cv output and see what kind of voltages/currents it puts out?

Then you could hook a power amp and a meter up to the input of your echoplex and turn it up until the echoplex is ruined, and then you'll know how much is too much. just kidding.

[The Scum]

It's really doubtful that this will work at all. Most audio devices don't want to pass DC voltages. If it's a tube echoplex, it probably doesn't want to pass DC at all - the single ended tube circuits will have been designed with coupling caps to remove any DC between stages. You might get some of the residual AC components (as clicks or thumps) on the track when the CV changes, but the DC will get lost along the way.

[joel hamilton]

does anyone know what a common range of synth control voltages are?

I'm really curious what would happen if I took the CV out of my moog and ran it through the echoplex, printing the CV to tape and delaying it, and then sending it out to a CV in on my friend's Korg MS-20 to control one or more parameters.

I just don't want to ruin my echoplex in the process.

Any clues?

It is 0-10 volts for most modular pieces, and you would need to use something designed for DC, regardless. You should look into a couple of modular pieces, as there are plenty of lag generators, slew limiters, CV limiters, and all manner of modules designed for exactly what you are trying to do, but unfortunately, as has already been stated, DC will not print.

[earl parameter]

typical voltages ranges are 5v, 10v, and +/-5v but those are mostly modular formats. self contained synths are almost always slightly or radically different. some 6v, others 12v. its best to just take a meter and start measuring the CV outputs to get an idea. and never send a device more voltage then it runs on!

as for sending 5v or more to the input of a device expecting line level which is:

+4 dBu = 1.228 V
−10 dBV = 0.3162 V

you could cause damage very easily. i have no idea what an echoplex can accept but i doubt its 10v. if you really really wanted to add delay to the voltage you could attenuation it to a reasonable level and then amp the output back to the desired voltage. but test on something a little less precious then an echoplex please.

- adding effects to CV always yields great results


now the third point. the MS-20 works on Volt/Hertz rather then Volt/Oct so you would need a converter to get it too work with your moog. i believe it was the MS-02 that did this so the MS series could be used in a V/Oct setup and they are very hard to find. there are supposed to be diy solutions but i?ve never looked for one as i don't own any MS's



steven

[earl parameter]

"DC will not print"

in some cases depending on how the circuit is designed and its power supply use this can be resolved with simply running the output through a larger 10u ( or something close ) cap.

maybe build a little DC blocking / attenuator utility box to keep around. shit, thats not a bad idea maybe i'll put a few together.


steven

[Babaluma]

i was gonna say usually 0-10v and audio circuits usually won't pass DC CV, but people have already done that so, without further ado: this idea was used extensively by morton subotnick a long time ago with his buchla system. he called it "ghost electronics" i think. there's a lot more info on peter grenader's site here:

http://www.buzzclick-music.com/mort_lore.html

[The Real MC]

You need a Wilson delay to process DC voltages. Serge makes a panel with a Wilson delay but that is an expensive option.

[???????]

Duh. DC.

CV is DC. Duh.

Sorry for wasting board real-estate.



Mainly I was just daydreaming of various "I wonder what would happen if" scenarios.

I certainly did not have a real application where I needed to delay CV.

I was just like "Hm... CV out on moog is 1/4, echoplex is 1/4, I wonder what would happen?....

Duh.

[earl parameter]

"CV is DC."

not always, check first



steven

[joel hamilton]

"DC will not print"

in some cases depending on how the circuit is designed and its power supply use this can be resolved with simply running the output through a larger 10u ( or something close ) cap.

maybe build a little DC blocking / attenuator utility box to keep around. shit, thats not a bad idea maybe i'll put a few together.


steven

I should have said: "DC will not print to tape on an unmodded echoplex."

Thanks for the great info, man. I knew someone would actually post a worthwhile response, as my synth knowledge is really only based on modular stuff... and making my own CV controllers out of volume pedals and 9V batteries doesnt qualify as "tech."

[apropos of nothing]

I love it when you guys talk modular, cuz its such a different world from the one I live in, but the concepts still apply, cuz synthesis is synthesis.

[inverseroom]

Also moog stuff is volts/octave, and Korg is hz/volt...

Plus some moog stuff is like .97 volts per octave, like the Micromoog, which I used to have. A huge freaking pain for interfacing...but nobody gave so much of a crap about interfacing a monosynth back then.