Yahoo Groups archive

emulatorII-list

Archive for emulatorII-list.

Index last updated: 2026-03-30 01:09 UTC

Message

Re: Don't know if the original caps were polar or bi-polar (E-II)

2012-12-15 by Gil

Will you please describe exactly what you see on your E-II as C66 and C67 on the audio board ??

What do you mean by two tantalums in series ?

Which values are they ? and how are they wired ?

If you could make a close up picture of the area I will be thankful !





--- In emulatorII-list@yahoogroups.com, "kgslug2" <kevingibson952@...> wrote:
>
> On mine, they are not even aluminium electrolytics. each is a pair of tantalums wired in series. I can't tell you if sampling works as at the moment my EII won't even boot.
> 
> Kevin
> 
> --- In emulatorII-list@yahoogroups.com, "Gil" <gilwe@> wrote:
> >
> > I haven't managed to get my Emulator II to sample from the day I got it.
> > 
> > I see no signal when playing into the input (using another synth, or an electric guitar).
> > 
> > I decided to investigate this further 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 while recapping the machine when I got it  a few years ago.
> > 
> > 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 / info on this ? Will anyone be able to take a look at his E-II voice board and check if these two electrolyte 4.7uf caps are bipolar (there should be a "NP" mark on them, and no polarity marking) ?
> > 
> > They are right under the power supply at the top-right corner of the left board.
> > 
> > The diagram is probably page 42 in the manual:
> > 
> > http://www.synthesizerarchiv.de/circuits/emu/emulator2_circuits/emulator2_circuits.pdf
> > 
> > Thanks !
> >
>

Attachments