Reply-To: "vintagesynthrepair@yahoogroups.com" <vintagesynthrepair@yahoogroups.com>
Date: Tue, 11 Dec 2012 16:16:26 +0100
To: "vintagesynthrepair@yahoogroups.com" <vintagesynthrepair@yahoogroups.com>
Subject: RE: [vintagesynthrepair] Re: Don't know if the original caps were polar or bi-polar (E-II)
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
T
o: 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, "Brian" <brian@...> wrote:
>
>
; You can replace with non-polar without any problem
>
>
>
> Regards
>
>; Brian G3OYU
>
>
>
> From: vintagesynthrepair@yahoogroups.com
> [mailto:vintagesynthrepair@yahoogroups.com] On Behalf Of Gil
> Sent: 10 December 2012 1:13
> To: vintagesynthrepair@yahoogroups.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 t
wo 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 !
>