Vintage Synth Repair

The board has the marking... not the non polar caps :/

It has the positive marks near each of the location where the non polar caps should go. This is what causes the confusion...
(scheme says non polar but there are marks on the board)



--- In vintagesynthrepair@yahoogroups.com, "Brian" <brian@...> wrote:
>
> Some non-polar caps do have a positive and negative marking, don't ask me
> why I don't know.  You would need to consult the schematic to ascertain
> whether or not the caps get reverse polarity volts on them at any time.
> 
> Regards
> 
> Brian G3OYU
> 
>  
> 
> From: vintagesynthrepair@yahoogroups.com
> [mailto:vintagesynthrepair@yahoogroups.com] On Behalf Of Gil
> Sent: 11 December 2012 9:07
> To: vintagesynthrepair@yahoogroups.com
> Subject: [vintagesynthrepair] Re: Don't know if the original caps were polar
> or bi-polar (E-II)
> 
>  
> 
>   
> 
> 
> Thanks,
> 
> I replaced them with bi-polars, no change in behavior (works just as before,
> no sample in signal).
> 
> What do you think ? should I keep the bi-polars there, or switch back to the
> polars ?
> 
> As I said before, the schematics calls for bi-polars, but the on the circuit
> board there are + signs near each cap, implying for polar capacitors... Why
> would they mark the polarity on the board if they ask for non-polar caps
> there ?
> 
> Just wondering...
> 
> --- In vintagesynthrepair@yahoogroups.com
> <mailto:vintagesynthrepair%40yahoogroups.com> , "Brian" <brian@> wrote:
> >
> > You can replace with non-polar without any problem
> > 
> > 
> > 
> > Regards
> > 
> > Brian G3OYU
> > 
> > 
> > 
> > From: vintagesynthrepair@yahoogroups.com
> <mailto:vintagesynthrepair%40yahoogroups.com> 
> > [mailto:vintagesynthrepair@yahoogroups.com
> <mailto:vintagesynthrepair%40yahoogroups.com> ] On Behalf Of Gil
> > Sent: 10 December 2012 1:13
> > To: vintagesynthrepair@yahoogroups.com
> <mailto:vintagesynthrepair%40yahoogroups.com> 
> > Subject: [vintagesynthrepair] Don't know if the original caps were polar
> or
> > bi-polar (E-II)
> > 
> > 
> > 
> > 
> > 
> > I have a nice Emulator II which doesn't sample from the day I got it.
> > 
> > You see no signal when playing into the input (using another synth, or an
> > electric guitar). 
> > 
> > I decided to investigate this and found that what seems to be the sampling
> > circuit, has two electrolyte caps, which on the schematics are marked as
> > "alum-electro (nonpolar) 4.7uf" but on the actual board, regular POLAR
> caps
> > are used. These caps I put myself when recapping the machine.
> > 
> > I tend to think that this causes the sampling circuit not to work,
> > BUT - a closer look at the board reveals a + sign near each of these two
> > caps, as if the engineers did intend to use regular POLAR caps there... 
> > 
> > I'm afraid to replace them with non-polars so I don't damage the circuit
> > ..... Any advice ?
> > 
> > You can see the diagram at page 42 of the manual, here:
> > 
> >
> http://www.synthesizerarchiv.de/circuits/emu/emulator2_circuits/emulator2_ci
> > rcuits.pdf
> > 
> > Thanks !
> >
>