This thread is a Q and A for the Voice of Saturn Sequencer.
Here are the first two questions we’ve received thus far:

Q1. Can I control my Yamaha CS-5 using the Voice of Saturn sequencer? (The CS5 does have CV and Gate on the back of it).

A1:
While I don’t have any of the Yamaha CS series, I think it should work with your CS5. It successfully controls my MS10, SH101, and Moog (Realistic) MG1 which pretty much covers all the trigger signal basses. The CV output of the sequencer is just a simple voltage that ranges from 0-~9v (it runs of 9v batteries, if you want something more stable that will last longer, its pretty easy to add a wallwart adapter to it – we don’t to make it cheaper and to avoid problems with ppl screwing up and zapping themselves). The trigger signal is either early korg/moog style s-trig, or a gate signal that goes from 0v – the 9v. Depending on what the CS takes as an input to the gate sig you could attenuate that level somewhat.

Q2. Can I control the Voice of Saturn synth with my Kenton Pro-2000 CV to Midi converter?

A2:
The voice of saturn synth is not currently something you can control with a midi-cv and get musical results. What I mean by this is that you can control it, but it will not scale like a regular synth. Building oscillators that precise is a bit beyond the scope of was I was able to do when i designed the VOS. Think of it as a crazy noise machine, but one that is still controllable by outside sources (sequencer, midi-cv, FSR). I have used teh Kenton Pro-2000 with it and its fun. You can also sync the sequencer with a midi-cv source as well (though its a little bit tricky).

Ok, i’ll bite…i’ve got a Eurorack modular synth i’ve been looking to augment with a sequencer. I’d prefer an outboard to save space in my case for more VCOs and the like. I’ve fallen in love with your design, and i think i’ll be able to solder it all up.

However, i have a couple questions, as i’m not an electronics whiz.

How hard would it be to add a stop/start button? i dont see one on there.

How hard would it be to make it v/Octave rather than hZ/Octave?

The gate signal goes from 0v-to-9v….but i believe my system, which is doepfer and bananalogue at present, is 0v-to-5v. Is it possible to scale it down at all, and if not, how would i use these together?

How about an octave switch? Or perhaps CV inputs on each step for varying the voltage via external means, like a ribbon controller?

Ok, i’m done being annoying for tonight :)

-vav

The hold switch is the start / stop button, although it won’t reset to the beginning of the sequence when started again.

I’m not exactly sure what hz/octave is… hz/v? right now you get a 0-9V (ish) signal out of each step that will work on either kind of input. The end result of that voltage depends on the instrument you’re driving.

Let’s say you want the sequencer to output C4,.. if your synth is hz/V, then you’d have to move the knob until it outputs 4.745V, and if the synth is octave/V, the knob would need to be turned until the step outputs 3.250 V. With either synth, the approach is the same: hit the hold switch so it stops on that step, and then adjust the knob until it sounds right. Since there are no note / key markings on each knob, the output of the sequencer isn’t ever “wrong” for a particular synth, it’s just voltage.

The only issue is that v/Oct schemes have a max of 5V input, so you could just not turn the knobs up all the way or make a voltage divider:

Take the output of the seq into one side of a pot, connect the far side to ground, and the wiper to the input of your 0-5V synth. Now set the seq step to max, and adjust the pot until the output reads 5V.

This same technique could be used on the gate signal… on the other hand, Travis, have you tried just plugging into a 5V system? Does it work?

“How about an octave switch? Or perhaps CV inputs on each step for varying the voltage via external means, like a ribbon controller?”

Good idea! But man, the front of that sequencer is already pretty full… I think the next feature is going to be a step shaper for the gate signal.

Hey vav,

The VoS seq should work quite well with the Eurorack stuff. To address your questions:

1 – start/stop button: The clock on/off switch does exactly this. with no clock, the sequence does not progress.

2 – v/oct vs hz/oct: the sequencer actually doesn’t care or isn’t calibrated for either. It just spits out a voltage from 0-supply (in this case a 9v battery). It works quite happily with my v/octave Korg MS10.

3 – gate signal: the gate signal path is a very simple, unbuffered implementation. basically, it takes the same starting point as the cv signal, so, if run of a 9v batter, the gate is 9v. You can easily add a resistor before the final output of the gate to drop the voltage a bit. Experiment with values, I don’t have one in front of me at the moment, but I can get back to you on this. Also, check your modules to see if a >5v gate is actually a problem. Many can accept up to 15v gate signals without getting fried.

As far as octave switches go, the 0-~9v range of the cv is typical of most pitch cv’s for full scale operation. An octave switch could be added, but there’s actually be a good amount of extra circuitry involved. basically it’d be like: low octaves 0-4.5 volts, high octaves 4.5-9 volts. Would require some buffer circuitry outside of the current pcb design.

Same kinda goes for cv inputs to control pitch of each individual step, buffers and vcas and such would be needed and are beyond the scope of this little seq.

My goal for the VoSS was to have a cheap and easy to construct voltage sequencer for my modular stuff and the VoS. The gate and s-trig signals are useful, but were more of an addition to the original design. It is important to note that the gate signals run together, so for one long gate, turn 3 switches on together, etc. the next versions (at least 6 months away) will have individual gate and trigger outputs, triggers being a gate signal on each step, no matter if they are in a row or not.

hope this answers your questions.

-Travis

Travis & Scott,

Thanks guys, that helped a lot. I think i will probably end up ordered the Sequencer soon :)

-vav

Okie doke, i ordered my kit, and now another question:

You say the voltage goes kind of wonky when the 9v begins to die. I like that idea, so i’m wondering how i’d use this:

http://www.analoguehaven.com/dwarfcraftdevices/powerstruggle/

with the sequencer.

Well my sequencer is up and running, and i love it.

Couple thoughts:

I’m thinking a good addition to the seq, or what i’ll probably buy, is a voltage quantizer. The Doepfer seems like a good bet, as it’ll help me get scale out of my ribbon controller too.

I think this may have already been covered, but i’m curious if it’s possible to control the clock’s rate via voltage control…say, the output of an LFO or the aformentioned ribbon controller.

Awesome, this is where I hope some questions of mine will be answered…
I built a PAiA Fatman recently and became interested in the idea of an analog sequencer. First, I’m not sure if the PAiA Fatman acts as a MIDI to CV converter or if it the CV jacks function as inputs (or both)? It has three CV jacks, pitch, velocity, and gate. Could I hook up the VOS Seq to the CV Pitch jack of a Fatman to drive it?
Secondly, does the VOS Seq control CV in V/Hz or V/oct or does each potentiometer just control voltage and you have to tune each step to the correct voltage scaling the synth you’re using is driven by?
Either way I’m going to end up buying one because I’m probably going to pick up a MFOS Sound Lab and I need to be able to control it somehow. Thank you for your replies!
~Nikolai