You mean what voltage do I read ? I get -0.03V at both pins 2 & 3.
Which 3086 you mean ? IC5 or IC6 ? I already changed IC4.
--- In Simmons_Drums@yahoogroups.com, "philmurr" <philmurr@...> wrote:
>
> What do you see at the inputs to IC3a (pins 2 & 3)? Lockup/down of IC3 is listed on the service scoops as a known issue so that could be the problem, you should get a constant sine on pin 1. Or if not then the 3086's may be at fault
>
> --- In Simmons_Drums@yahoogroups.com, "scistudio440" <nuipb@> wrote:
> >
> > OK, I did that touching pin 1 of each IC3. I get a clear sine from each of them except from the faulty voice which is mute. Does that mean that the LM1458 is dead ?
> >
> > --- In Simmons_Drums@yahoogroups.com, Michael Buchner <buchnerelectronics@> wrote:
> > >
> > > Build yourself a signal follower. Take an active PC speaker, connect ground of its cinch to the SDS3s ground. Solder a piece of wire to the tip and touch the different points. And listen!
> > >
> > > Von meinem iPhone gesendet
> > >
> > > Am 03.08.2013 um 21:54 schrieb "scistudio440" <nuipb@>:
> > >
> > > > Thanks Michael and Phil for your advices.
> > > > Yes I am getting noise on all other 3 voices.
> > > > When you say "check the VCF output" I understand you mean pin 1 or 7 of IC3 right ?
> > > > Since i have no oscilloscope is it possible to conclude anything useful with a multimeter ?
> > > > FWIW I am reading 0.09V on pin 1 and 0.02V on pin 7. I also read 15.40V on pin 8 and -15.14V on pin 4
> > > >
> > > > --- In Simmons_Drums@yahoogroups.com, "philmurr" <philmurr@> wrote:
> > > > >
> > > > > I had to replace all 3086's in my SDS-IV, both channels before I could get reliably working sound again.
> > > > >
> > > > > The noise generator is common to all channels so if you're getting noise on at least one channel then the noise generator is fine.
> > > > >
> > > > > The only other thing to check is IC3a the VCF output.
> > > > >
> > > > > I've recently fixed an SDS-III and had a play with the sounds once fixed, and am still amazed at what it can produce. As Michael says, good luck, it will be worth it !
> > > > >
> > > > > --- In Simmons_Drums@yahoogroups.com, "Michael Buchner" <buchnerelectronics@> wrote:
> > > > > >
> > > > > > Yes, it is the famous Moog VCF.
> > > > > >
> > > > > > Yes, pitch is Cutoff Frequency.
> > > > > >
> > > > > > Check the CV and listen with a signal follower at each of the 4 ladder capacitors of the filter.
> > > > > >
> > > > > > Good luck
> > > > > >
> > > > > >
> > > > > > ----- Original Message -----
> > > > > > From: scistudio440
> > > > > > To: Simmons_Drums@yahoogroups.com
> > > > > > Sent: Friday, August 02, 2013 8:43 PM
> > > > > > Subject: Re: [Simmons Drums] SDS-3 trimmers
> > > > > >
> > > > > >
> > > > > >
> > > > > > OK. So now after sorting one silent voice (CA3086 was the culprit) I have another silent voice to sort (which was working fine before I tried to sort the first voice...).
> > > > > > When tweaking the trimmer beside the Impact knob something like a resonance started to appear. This is when I understood something that is probably obvious to most of you that there is no oscillator per se in a SDS-III module but more exactly a self-oscillating filter, right ?
> > > > > > Pitch standing for cutoff frequency, which becomes very obvious when switching from Tone to Noise.
> > > > > > So as I said, when I tweaked the trimmer beside the Impact knob a resonance started to appear but very unstable. As long as I could hear it the voice worked again but then after some time the oscillation/Tone became even more unstable and disappeared again. And now impossible to make it come back even when tweaking that trimmer. The noise is also silent.
> > > > > > Would anyone have any idea what could be happening ?
> > > > > >
> > > > > > --- In Simmons_Drums@yahoogroups.com, "scistudio440" <nuipb@> wrote:
> > > > > > >
> > > > > > > Vielen Dank !
> > > > > > >
> > > > > > > --- In Simmons_Drums@yahoogroups.com, "Michael Buchner" <buchnerelectronics@> wrote:
> > > > > > > >
> > > > > > > > The one near Impact is the filter symmetric (you can remove the distortion, but there isn't any). The one near bend up down is the adjustment of the VCA input, removing the DC pop. WITH DC pop it sounds better :-)
> > > > > > > > Near the master output slider is one trimmer to adjust the range of the RUN generator.
> > > > > > > >
> > > > > > > > Best
> > > > > > > >
> > > > > > > > Michael
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > ----- Original Message -----
> > > > > > > > From: scistudio440
> > > > > > > > To: Simmons_Drums@yahoogroups.com
> > > > > > > > Sent: Wednesday, July 31, 2013 12:59 PM
> > > > > > > > Subject: [Simmons Drums] SDS-3 trimmers
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > Hi list,
> > > > > > > >
> > > > > > > > Would anyone know what are the trimmer beside the Impact Click level and the trimmer beside the Bend level for ? And also the one beside the Output level slider ?
> > > > > > > >
> > > > > > > > Thanks for your help,
> > > > > > > > Phil
> > > > > > > >
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