Yahoo Groups archive
Thread
2012-05-10 by ambrosia800
Hi there... I have a problem with my Prodigy, first version. After switching it on, the scaling of OSC2 id not working properly anymore. Even if I turn the trimpot on the rear all to the right, the scaling will not be good... it will be better, but not OK. What could be the problem? OSC1 is fine, everynthing else is working.
2012-05-12 by ambrosia800
Nobody any ideas? Regards --- In vintagesynthrepair@yahoogroups.com, "ambrosia800" <s_carter@...> wrote:
> > Hi there... > > I have a problem with my Prodigy, first version. > > After switching it on, the scaling of OSC2 id not working properly anymore. > Even if I turn the trimpot on the rear all to the right, the scaling will not be good... it will be better, but not OK. > > What could be the problem? OSC1 is fine, everynthing else is working. >
2012-05-12 by Lorne Hammond
Often scaling for the oscillators interact, so you want to be precise about osc 1 as if its off a tiny bit it may impact osc2? That's a guess, not experience. Lorne From: vintagesynthrepair@yahoogroups.com [mailto:vintagesynthrepair@yahoogroups.com] On Behalf Of ambrosia800 Sent: Saturday, May 12, 2012 10:10 AM To: vintagesynthrepair@yahoogroups.com Subject: [vintagesynthrepair] Re: Prodigy scaling problem Nobody any ideas? Regards --- In vintagesynthrepair@yahoogroups.com <mailto:vintagesynthrepair%40yahoogroups.com> , "ambrosia800" <s_carter@...> wrote: > > Hi there... > > I have a problem with my Prodigy, first version. > > After switching it on, the scaling of OSC2 id not working properly anymore. > Even if I turn the trimpot on the rear all to the right, the scaling will not be good... it will be better, but not OK.
> > What could be the problem? OSC1 is fine, everynthing else is working. >
2012-05-12 by ambrosia800
Hi Lorne, Osc1 is perfect in tune, no problem there. Only Osc2 impacted.. --- In vintagesynthrepair@yahoogroups.com, "Lorne Hammond" <lhammond@...> wrote:
> > Often scaling for the oscillators interact, so you want to be precise about > osc 1 as if its off a tiny bit it may impact osc2? That's a guess, not > experience. Lorne > > > > From: vintagesynthrepair@yahoogroups.com > [mailto:vintagesynthrepair@yahoogroups.com] On Behalf Of ambrosia800 > Sent: Saturday, May 12, 2012 10:10 AM > To: vintagesynthrepair@yahoogroups.com > Subject: [vintagesynthrepair] Re: Prodigy scaling problem > > > > > > Nobody any ideas? > > Regards > > --- In vintagesynthrepair@yahoogroups.com > <mailto:vintagesynthrepair%40yahoogroups.com> , "ambrosia800" <s_carter@> > wrote: > > > > Hi there... > > > > I have a problem with my Prodigy, first version. > > > > After switching it on, the scaling of OSC2 id not working properly > anymore. > > Even if I turn the trimpot on the rear all to the right, the scaling will > not be good... it will be better, but not OK. > > > > What could be the problem? OSC1 is fine, everynthing else is working. > > >
2012-05-12 by Lorne Hammond
Capacitor or trimmer? From: vintagesynthrepair@yahoogroups.com [mailto:vintagesynthrepair@yahoogroups.com] On Behalf Of ambrosia800 Sent: Saturday, May 12, 2012 12:15 PM To: vintagesynthrepair@yahoogroups.com Subject: [vintagesynthrepair] Re: Prodigy scaling problem Hi Lorne, Osc1 is perfect in tune, no problem there. Only Osc2 impacted.. --- In vintagesynthrepair@yahoogroups.com <mailto:vintagesynthrepair%40yahoogroups.com> , "Lorne Hammond" <lhammond@...> wrote: > > Often scaling for the oscillators interact, so you want to be precise about > osc 1 as if its off a tiny bit it may impact osc2? That's a guess, not > experience. Lorne > > > > From: vintagesynthrepair@yahoogroups.com <mailto:vintagesynthrepair%40yahoogroups.com> > [mailto:vintagesynthrepair@yahoogroups.com <mailto:vintagesynthrepair%40yahoogroups.com> ] On Behalf Of ambrosia800 > Sent: Saturday, May 12, 2012 10:10 AM > To: vintagesynthrepair@yahoogroups.com <mailto:vintagesynthrepair%40yahoogroups.com> > Subject: [vintagesynthrepair] Re: Prodigy scaling problem > > > > > > Nobody any ideas? > > Regards > > --- In vintagesynthrepair@yahoogroups.com <mailto:vintagesynthrepair%40yahoogroups.com> > <mailto:vintagesynthrepair%40yahoogroups.com> , "ambrosia800" <s_carter@> > wrote: > > > > Hi there... > > > > I have a problem with my Prodigy, first version. > > > > After switching it on, the scaling of OSC2 id not working properly > anymore. > > Even if I turn the trimpot on the rear all to the right, the scaling will
> not be good... it will be better, but not OK. > > > > What could be the problem? OSC1 is fine, everynthing else is working. > > >
2012-05-12 by evening1
Nobody any ideas?
Regards
--- In vintagesynthrepair@yahoogroups.com, "ambrosia800" wrote:
>
> Hi there...
>
> I have a problem with my Prodigy, first version.
>
> After switching it on, the scaling of OSC2 id not working properly anymore.
> Even if I turn the trimpot on the rear all to the right, the scaling will not be good... it will be better, but not OK.
>
> What could be the problem? OSC1 is fine, everynthing else is working.
>
2012-05-17 by duncan
to the OP- the schematic is in "files" here. a bit rough, but legible. if you are not comfortable following the schematic & poking around with a DVM, then print out the schematic & take it to a tech. I'm looking at it now, & I suspect you're going to find that the 3046 array at U3 is misbehaving. if you're feeling brave, you might re-route the voltage control from osc one into osc two (at the TL082, U10). if it's still wildly out (i.e. not even in the same state, let alone the ballpark) then you're looking at a problem with the osc itself, not the voltage control. that probably points at the FET, Q16. bon chance! duncan.