Question about SID

Design Concepts
1

Hi, I have a question about the following line in the SID specs:

“3 AMPLITUDE MODULATORS Range: 48 dB” - What do they do?

furthermore I read in the CC implementation of the MIDIBoxSID the following:

45 | 2Dh | Filter Mode
    |     |   Bit 0: LowPass on/off
    |     |   Bit 1: BandPass on/off
    |     |   Bit 2: HighPass on/off
    |     |   Bit 3: Voice 3 off

What is the purpose of turning Voice 3 off as a Filter option? Isn’t this done by using the “bypass filter” option for OSC 3? Or are they totally different things?

Thanks in advance.

2

Hi,

the amplitude modulators are used by the internal envelope generators of the SID. Unfortunately it isn’t possible to control the amplitude levels directly - would be a nice extension for the LFOs :slight_smile:

The voice 3 off flag disconnects the third oscillator (which can optionally used as sync or ringmodulation master) from the output amplifier. It’s usefull if you only want to hear the sound of the slave oscillators

Best Regards, Thorsten.