Configuring volume to aout

MIDIbox SID
1

I am trying to get my SSM2164 boards to play with the MB6582 but i’m having some problems.

I got it running with SSM2044 filters on channel 1-4 of the AOUT_NG and i have assigned volume out to channel 5 and 6

#define AOUT_INTERFACE_TYPE 3


...


#define DEFAULT_F2A_CUTOFF_L_AOUT	1

#define DEFAULT_F2A_RESONANCE_L_AOUT	2

#define DEFAULT_F2A_CUTOFF_R_AOUT	3

#define DEFAULT_F2A_RESONANCE_R_AOUT	4


...


#define DEFAULT_V2A_VOLUME_L_AOUT	5

#define DEFAULT_V2A_VOLUME_R_AOUT	6

I have allso set all other aout options to 0 to not conflict with the options i want to use.

In the ensemble settings ext menu I have set F2A and V2A.

When I measure the output at the AOUT_NG channel 5 and 6 I get a constant 10V. The only way I have been able to change that output is to inverse the signal from the ens->ext menu (setting Iv5 or Iv6).

Isn’t the output supposed to be about 0V then no note is played and 10V when a note is played?

There must be some configuration I have missed.

Grateful for any help.

2

The V2A function doesn’t (resp. can’t) mirror the SID internal VCA envelope , it only transports the patch volume setting to the AOUT channel.

If you want to control the VCA from an envelope, you have to link ENV1 or ENV2 to volume via modulation matrix.

The VCA offset level should be controllable with the CFG->Vol parameter, can you confirm this?

Best Regards, Thorsten.

3

interesting topic. i’m about to give my stereo sid its final case and haven’t tried the VCA module yet (just the VCF).

so is it possible to control the vca from the same AOUT_NG that i use for the VCF?

that would reduce the needed aouts for the MB6582 to to just 4!

(so that would be just a 1 AOUT_NG per core setup then)

4

TK: Ah, thanks. That explains it all. I can confirm that the volume setting is propagated even though the response is linear (volume appears very low until settings above 100). I will experiment some with the modulation matrix. I guess it is impossible to get access to the SID chips VCA envelope…

Rosch: I am using 1 AOUT_NG per synth engine to control one SSM2044 board and 1/2 SSM2164 board per synth engine. and can confirm that it works.

5

cool, thanks!

6

http://discourse.midibox.org/t/topic/16325

I don’t get full range volume modulation when modulating volume with EG and LFO even though the depth is set to 127.

The CFG->Vol parameter works flu range. Either there is something more I don’t understand or there is trouble with the firmware…