Hey,
So I've almost finished my x0x, exept for one little detail.
When playing, the notes sustain forever. So I'm thinking this is because there is something wrong with the envelope generator. Though as soon as I turn up the env mod pot, the envelope starts to influence the behaviour of the filter. So that indicates that there could be something wrong with the VCA. Unfortunately, all my efforts to find an error where unsuccsessful up to now. So my question is: Has anyone ever had this or a similar problem? Any ideas what to check next?
Envelope doesn't influence VCA
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- antto
- Posts: 1636
- Joined: Thu Apr 15, 2010 3:21 pm
Re: Envelope doesn't influence VCA
the VCA uses a sepparate envelope generator (not the main one which is used for the VCF)
go to keyboard mode and press down some note for ~10 seconds - it should decay down
go to keyboard mode and press down some note for ~10 seconds - it should decay down
- ivo francx
- Posts: 13
- Joined: Wed Feb 05, 2014 6:03 am
Re: Envelope doesn't influence VCA
Nope, didn't work... I've even tried holding the buttons longer than 10 seconds. But still no stopping the VCA...
- ivo francx
- Posts: 13
- Joined: Wed Feb 05, 2014 6:03 am
Re: Envelope doesn't influence VCA
Could you point out where the second envelope generator is located? I'm kinda having a hard time finding it.
- antto
- Posts: 1636
- Joined: Thu Apr 15, 2010 3:21 pm
Re: Envelope doesn't influence VCA
it's C42, located in the VCA section
it generates a Decay envelope (with fixed time) which is applied thru Q31 into the opamps (IC15)
it's supposed to fade away for roughly 5-7seconds
it generates a Decay envelope (with fixed time) which is applied thru Q31 into the opamps (IC15)
it's supposed to fade away for roughly 5-7seconds
- mmm
- Posts: 517
- Joined: Tue Apr 24, 2012 1:51 am
Re: Envelope doesn't influence VCA
Check the voltage at the cathode of D27 when playing a note. This should give you the proper envelope voltage before it enters the current mirror.
Please be positive and constructive with your questions and comments.