posted 04 December 2009 09:34            

I am using your fabulous String Machine Plus, and I had a question for you about this sound.

If you look at the waveform of this sound, there is a strong DC component, which is a problem when you want to turn up the volume, because very soon the DC component hits the ceiling, which has the consequence to eventually produce not sound at all.

I would like to know if it is possible either to change the algorithm so there is less DC, or add a DC bias remover (how can it be done?), this way the sound could be played louder, and most of all wouldn't add a DC component in my mixes !

Thanks for this great sound.

posted 04 December 2009 14:33            

I hadn't even noticed the DC. Any way I can see what it is thats doing it.

The Oscillator is a basically a cos wave and uses the formant control to squash part of it up a leaving a hole for the rest of the wave forms duration.

This hole is at +1 DC because the cos wave starts and ends there.

There is a simple cure....

The signal coming out of the MIDIVoice is a poly mix of all the oscillators and is in mono. I know it has two wires but it's still mono. So grab a HighPassFilter from the prototypes and drop it between the MIDIVoice and the mixer named "Sample + SawSqareAdditive LITE". Then set it up the filter as follows

HighPass = Ticked
Frequency = 10hz
Q = 0
Scale = 1
Feedback = 0
Order = 1

That should do the trick and add next to nothing to the DSP requirements.

If you need extra gain then put it after this filter.

Hope it helps

Pete

BTW to make it more like those early string machines you should adjust the range in the VCS of the Attach to 0 to 4 and the Decay to 0 to 10, or something like that (to taste).

posted 04 December 2009 16:00            

Another thought

When I made the module I had to use the osc for the keyboard controlled poly bit as it was cheap in DSP usage.

What I really wanted was the SOS generated anti aliased rich bodied generator, which you can see in the SawSquare Additive leg. You hear this bit when you turn up AmpLow, But this is non poly and the frequency is controlled by LogFreq. That was because very few Capys could deal with a poly version of this.

But now that we have Pacas and the like, this could become the Poly Keyboard controled sound generator as there is so much DSP power around now.

It would need the MIDIVoice to be placed between the SawSquare Additive LITE and the mixer. It would need a VCA placed to the left of the new MIDIVoice and a copy of the AR module in the VCAs input as well. Then all the !LogFreq s would have to be replaced with (!KeyNumber+!Tune). There are a lot of them.

It would probably need some funky tricks with the !LoCut to make it follow the !KeyPitch and not have such a sharp cut off.

Then it would be a big fat string Machine with loads of bass nothing like the old 70s Machines.

Just a Thought

posted 04 December 2009 19:52            

StringMachinePlus2.kym

Just made a few improvements on the StringMachinePlus.

Not the Fat thing I talked about but now the sound becomes silent in the gaps. Before the switched off oscillators would bleed through. Also added Flute and Trumpet presets or as flutey or trumpety as you can get with a string machine.