Well, here are my test. Seems to be a bit weird. I've multimetered my ics when my pots where center positionned
i can see that if i approach my fingers to the pots or some parts it's altering the sound...
I've rechecked all my links & solders...
IC1 / TLO72
1 : -1,55v
2 : 0
3 : 0
4 : -15
5 : 0
6 : 0
7 : 0
8 : 15
IC2 LM394/2N3904
1 : 0
2 : 0
3 : -0,5
4 : nc
5 : nc
6 : -0,5
7 : 0
8 : 0
IC3 : TLO72 near the unicorn
1 : 0
2 : 0
3 : 0
4 : -15
5 : 0
6 : 0
7 : 0
8 : 15
IC4 / CA3140
1 : -15
2 : 0
3 : 0
4 : -15
5 : -15
6 : 2
7 : 15
8 : 3,5
IC5 / LM3900
1 : 0,1v
2 : 0,4
3 : 0,5
4 : 0,15
5 : 0,15
6 : 0,55
7 : 0
8 : 0,53
9 : 2,2
10 : 2,2
11 : 0,5
12 : 0,37
13 : 0,37
14 : 15
IC6 / LM311
1 : -15v
2 : 2,2
3 : 4,96
4 : 15,3
5 : 15
6 : 15
7 : -15
8 : 15
IC7 / TLO72
1 : BTW +6 & +12
2 : 0
3 : 0
4 : -15
5 : BTW -2 & +2
6 : -0,3
7 : BTW -8 & +12
8 : 15
i can see that if i approach my fingers to the pots or some parts it's altering the sound...
I've rechecked all my links & solders...
IC1 / TLO72
1 : -1,55v
2 : 0
3 : 0
4 : -15
5 : 0
6 : 0
7 : 0
8 : 15
IC2 LM394/2N3904
1 : 0
2 : 0
3 : -0,5
4 : nc
5 : nc
6 : -0,5
7 : 0
8 : 0
IC3 : TLO72 near the unicorn
1 : 0
2 : 0
3 : 0
4 : -15
5 : 0
6 : 0
7 : 0
8 : 15
IC4 / CA3140
1 : -15
2 : 0
3 : 0
4 : -15
5 : -15
6 : 2
7 : 15
8 : 3,5
IC5 / LM3900
1 : 0,1v
2 : 0,4
3 : 0,5
4 : 0,15
5 : 0,15
6 : 0,55
7 : 0
8 : 0,53
9 : 2,2
10 : 2,2
11 : 0,5
12 : 0,37
13 : 0,37
14 : 15
IC6 / LM311
1 : -15v
2 : 2,2
3 : 4,96
4 : 15,3
5 : 15
6 : 15
7 : -15
8 : 15
IC7 / TLO72
1 : BTW +6 & +12
2 : 0
3 : 0
4 : -15
5 : BTW -2 & +2
6 : -0,3
7 : BTW -8 & +12
8 : 15
--- In cgs_synth@yahoogroups.com, <lofideadbeat@...> wrote:
Well, thanks for your answer Ken... I think my problem is somewhere else, but can't see where.
If i use my sequencer on the vc fm, i can modulate the vco.
If i apply the same cv output to the cv in, my vco doesn"t respond. If i apply the cv output to the 1v/o in, nothing. If i apply 1v to the 1v/o input, nothing..
I've got 0v on ic1 pin 7, when i've got my tune and freq pot in center position, but if i try to move them, they don't modulate a lot ( maybe from 11 to 1 oclock).
thanks for any help. I gonna check all the ics voltages and send it there, maybe it'll help !
--- In cgs_synth@yahoogroups.com , <sasami@...> wrote:
If the span trimmer is not right, the VCO may be too sensitive to CV and to
the tuning pot.
Ken
>Hi Everybody ! That's my first post here, as after building several
modules, i think i've got some problems to fix on my cgs48. I've
used a 2N3904 matched pair instead of the LM394. I think that my vco is
working, but i can't really use the initial freq pot. It must be always
in its center position if i want to hear the vco. Is it normal ? I only can
tune the vco using the fine pot... In a post here, i've seen i could
change the 1m resitor to a 2,2m one, and i did this change, but it just
affect the fine tune pot, no the intial one. What should i check ? thanks
for any help ! jean
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale < http://www.cgs.synth.net/ >