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@paintingwithsound.co.nz<br>
www.paintingwithsound.co.nz<br>
[Non-text portions of this message have been removed]