Discussion about the Korg PolySix synthesizer

It turns out that there's not enough space under the board for these tall Mylar caps.  But, once I got access to the underside of the board, I saw that the caps did have a little extra length on their legs on the bottom side of the board that I could loosen them up with my soldering iron, push them so that they stand a bit taller, and then simply bend them over so that they are out of the way.

Now they lay a bit flatter, which is just enough to let my new keybed sit down at the height that it's supposed to.  Yay!

Pics coming a bit later...

Chip


--- In PolySix@yahoogroups.com, "chipaudette" <chipaudette@...> wrote:
>
> Whoa.  Other side of the board?  There's a cool idea!
> 
> Chip
> 
> --- In PolySix@yahoogroups.com, Murray <murray@> wrote:
> >
> > no, don't use ceramic. Why don't you move the existing ones to the other 
> > side of the board?
> > 
> > Just a thought
> > 
> > MH
> > 
> > On 4/05/2013 8:51 a.m., backshall1 wrote:
> > >
> > > According to Analog.com
> > > http://www.analog.com/library/analogDialogue/Anniversary/21.html, you 
> > > should
> > > be using any of the "poly" (polystyrene, polypropylene, Teflon) types 
> > > for a
> > > sample and hold circuit, since a ceramic cap has considerable dielectric
> > > absorption which can cause a type of charge memory that can cause 
> > > errors in
> > > hold level. Some polystyrene caps can be rather tall, so you would have to
> > > choose carefully. The old mylars look like they are about 10mm high. The
> > > caps I'm using on the clone boards are about 8mm, so there is not much
> > > difference. How much clearance do you need for the new keybed? If the old
> > > caps weren't soldered so close to the board, you could just bend them over
> > > so they would lie flatter.
> > >
> > > Don B.
> > >
> > > _____
> > >
> > > From: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> 
> > > [mailto:PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>] On 
> > > Behalf Of
> > > chipaudette
> > > Sent: Friday, May 03, 2013 12:05 PM
> > > To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
> > > Subject: [PolySix] Mylar caps on the sample-hold circuits on KLM-367
> > >
> > > Hi Folks,
> > >
> > > Some of you may know that I've replaced the keybed on my Polysix. The new
> > > keybed has a long metal cross-bar that sits a little lower than the one on
> > > the stock keybed. The new keybed is running into the tall 0.047uF 
> > > Mylar caps
> > > that are standing tall from the KLM-366. Specifically, I'm talking about
> > > C31-C36 that are the caps that hold up the sample-and-hold output from 
> > > IC29.
> > >
> > > Being too tall, I'm thinking about replacing them. They're listed as 50V
> > > Mylar caps. Would it be OK to replace them with 50V ceramics instead? The
> > > ceramics are WAY smaller and would allow my new keybed to fit easily.
> > >
> > > The signals being held by these caps is only used for the keyboard 
> > > tracking
> > > of the VCF, so it's not like I need a cap with ultimate fidelity. I think
> > > that I need a cap that holds its DC value very well (which is the point of
> > > the S-H).
> > >
> > > Would a ceramic be OK here?
> > >
> > > Chip
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > > 
> > 
> > -- 
> > Kind Regards<br>
> > Murray<br>
> > murray@<br>
> > www.paintingwithsound.co.nz<br>
> > 
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>