Korg Poly800/EX800 Users

So, just to be on the safe side, I did replace that polarized cap that I installed last night with an NP cap -- again, to be consistent with the original design.

I've got to say that I'm less than impressed with the 12dB mod. To my ear, it sets a lower cutoff frequency or something. Seems like the brilliant highs are missing. I hear more subtlety in 24dB mode. I think Korg got it right when it chose this over 12dB.

Just one man's opinion....

aaron

--- In korgpolyex@yahoogroups.com, "AARON" <aaron3900@...> wrote:
>
> Hi Mike,
>
> Yes, I noticed that it was non-polarized when I was taking it out last night.
>
> I assume that Dave came to that conclusion that it's a polarized cap because the PCB has a "+" where one of the leads solders into the board. But from the standpoint of wiring up the 12/24dB mod, the distinction is important, I think, because if you take the other lead -- the "negative" one -- and wire that one up to the switch, it won't work. So I guess he means simply that the lead that's stuck into the hole marked "+" is the one to use.
>
> By the way, I replaced C103 with a polarized cap last night (soldering the positive lead into the hole marked "+" on the board), and everything's working fine. I guesss whether you use a polarized or non-polarized cap really isn't critical here.
>
> Aaron
>
> --- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@> wrote:
> >
> > C103 is a non polarised electrolytic cap. It is not polarised and does not have a + or - pin. I am not sure how Dave came to the conclusion that the cap has a positive and negative side. But it doesn't.
> >
> > Mike
> >
> >
> >
> > ________________________________
> > From: AARON <aaron3900@>
> > To: korgpolyex@yahoogroups.com
> > Sent: Monday, November 12, 2012 2:25 PM
> > Subject: [korgpolyex] Re: Schema for 12/24 dB filter cutoff slope mod: new file (JPG) and photo uploaded
> >
> >
> > Â
> > Hi all,
> >
> > I'm a new member here, but certainly not new to the Poly 800 (I own two) or modding (I've done the Moogslayer mod on one of my machines).
> >
> > I'm glad I found this particular thread. Before I became a member today, I found a 2003 thread regarding this mod by doing a Google search. It said to use the NEGATIVE lead of C103.
> >
> > So last night, I excitedly got to work on the mod, wired it up exactly as instructed and got ... well, a big bunch of nothing. No sound at all. So, I had to replace C103 with a new 10uF cap (since I'd already cut the negative lead loose from the board), and the synth now works again.
> >
> > Tonight, I'll try 'er again with the revised instructions. I may just replace C103 with a 10uF axial-lead capacitor (soldering in just the negative lead, of course) to make the job a bit easier. I'm eager to hear how this mod sounds!
> >
> > Cheers to Dave for sharing the revised info (in 2007).
> >
> > Aaron
> >
> > --- In korgpolyex@yahoogroups.com, "Dave Bowman" <davidmochen@> wrote:
> > >
> > > Hi all,
> > >
> > > Having been requested by a member of this NG to provide some details
> > > about the 12/24 mod (which of course I didn't happen to create, but
> > > nevertheless managed to implement succesfully), I just uploaded a jpg
> > > file to the Files section and a photo to the Photos section in my
> > > album (Dave's Poly 800).
> > >
> > > I hope this may be of help, since the mod's description featured in
> > > an older post, though useful, unfortunately has a mistake as regards
> > > the C103 capacitor's polarity.
> > >
> > > I performed the mod exactly as is described in the pic/file, and it
> > > works fine.
> > >
> > > Sorry for the spellcheck lines under the words... I created the
> > > schematic using Microsoft Word and forgot to turn the autospell
> > > feature off... it's late here in Argentina and I should collapse in
> > > bed right now!
> > >
> > > Cheers,
> > >
> > > Dave
> > >
> >
>