Question about cv sequencing

So, I've built a CV sequencer, & seem to have it working, more or less. The CV signal goes to the CV on my MS-10, & the CV out on the MS-10 goes to the trigger. It makes all sorts of different pitches & blippy noises. Problem is, I seem to lose envelope control while it's running (altering attack/decay/sustain/release has no effect), meaning I can't produce anything but blippy noises. Is there a way to change this?

you have a gate output on your sequencer?? How did you learn to build stuff?

From my limited expertise, if you only send pitch voltage, you only get pitches. You have to send envelope gate as well. I have no idea how you would go about doing that, though.

  On 3/12/2010 at 1:55 AM, marf said:

you have a gate output on your sequencer?? How did you learn to build stuff?

I don't think so, & mostly by trial & error.

Actually, I figured out how to get envelopes working (by using an external trigger instead of the CV out), now I just need to work on making the signal less noisy. Big annoyance right now is that the potentiometers keep popping out of the breadboard, & I don't want to solder them in until I have the circuit totally figured out.

You need to eliminate variables - get a second CV synth. Then you'll no if it's the synth or the sequencer.

I only have the one at the moment, unfortunately...

Though I'm pretty sure it is the sequencer, because the synth has never given me any problems & the sequencer looks like this-

The noisy signal may be from wires crossing, because when I tried yanking some stuff out just now it became a lot cleaner. I think tomorrow I'll try reassembling it while it's running to see what's causing the problem.

well it might be a "feature" that the MS10 stops reponding to its envelope knobs when it's receiving CV. having another synth to try would be one way to check that. you might be able to borrow a synth off somebody, especially if you promise to build them a sequencer

  Quote

well it might be a "feature" that the MS10 stops reponding to its envelope knobs when it's receiving CV

Close. From a test it seems that the envelope stops working whenever something is hooked to the CV Out, which I had running to the trigger. I switched the trigger over to one of the outputs on my 707, which allowed me to regain envelope control while still receiving CV signals. At the moment the CV signals sound like they're giving out several different voltages at once, so I think I'm going to have to test the circuit one step at a time (and buy better potentiometers).

CV is a continuous signal. I think you have to find out what voltages the MS takes and build your sequencer to output the proper voltages. I think you need a gate output.

Read about the SQ-10 maybe

A long shot: Are you using Arduino and its digital output? If so you need to increase the clock frequency on the output, or the fake analog signal (via pulse width modulation) will frequency modulate the oscillator. And that can sound like several different cv values at once.

It's pretty hard to tell what is going on from your description, but one thing I would look at is to make sure that your gate signal is providing discrete note events - that is, it's going from low to high each time it should be triggering a new note. Otherwise, if the gate signal just stays at +5v (or whatever it is - you should check both what your sequencer is outputting and what kind of signal the MS10 requires) the entire time the sequence is running, then that's pretty much equivalent to just holding down a single key with respect to envelope triggering. That's the problem I ran into trying to drive my modular from a friend's SH101 arpeggiator ... not sure if we did ever get it sorted out ...

I think I have the synth part all sorted out. The circuit is coming along - the notes are a lot cleaner now, problem is it's still not advancing through the sequence. I'm guessing there must be a short somewhere.

Marf nailed it. It's surprising you are getting ANY noise out of it if you aren't sending in s-trigs to the gate input.

As for the noise, if your cv signal is noisy, the output on your synth will be noisy, too. I suspect you have a crystal in your circuit somewhere? It's probably coming from that thing...had a friend that built a MIDI->cv converter and it took him ages to get the crystal to shut up.

Read the part about the MIDI 2 CV converter

Yeah, as stated that won't work. You need both a CV output and Gate or Trigger output from the sequencer you're building for the envelope to be triggered.