JordanAceto / josh_Ox_ribbon_synth

ribbon synth for Josh Oxford
Creative Commons Attribution 4.0 International
1 stars 0 forks source link

main VCO board: noise switch to the audio mixer should be ON-OFF-ON with WHITE-OFF-PINK noise #8

Open JordanAceto opened 2 years ago

JordanAceto commented 2 years ago

On the main VCO board, each audio signal going into the audio mixer has a switch to turn it on or off. Most signals use an ON-OFF-On switch to select two versions of the signal, such as the suboctaves which allow you to choose between base octave and -1 octave versions, and the ring-mod which allows you to choose between VCO * Modosc and VCO * VCO.

Right now, the WHITE/PINK noise switch is on the S&H board. But it would be more useful if this switch were moved to the VCO, and changed to the ON-OFF-ON topology as described.

This will require modifying both the S&H board and the main VCO board. The wire headers that connect the S&H and VCO will need an extra wire to carry the pink noise signal.

Whether or not to keep the WHITE/PINK noise switch on the S&H is an open question. I'm somewhat inclined to remove it, but otoh maybe just leave it there as well. The noise is sampled by the S&H, white vs pink doesn't make tons of difference here. But the noise can also modulate the VCO and VCF via the S&H mixer, and white and pink will sound a little different when used directly as modulation sources.

My general plan now is: change the VCO switch to WHITE-OFF-PINK, and add a wire to the headers connecting the VCO and S&H. Leave the WHITE/PINK switch on the S&H board. I could be convinced to change this setup though. Give it some thought.

JordanAceto commented 2 years ago

Note that Ox has recently requested that the switches go MODE 1 -> MODE 2 -> OFF, instead of MODE 1 -> OFF -> MODE 2.

There is another open issue about this.

I'm not positive this change will happen, but make sure to coordinate any noise switch changes with broader changes to the switch order.