Discussion about the Korg PolySix synthesizer

Thanks Don,

You advice and expertise are much appreciated! I shall have a bit more of an
experiment, but I am at least ending up with the playable instrument for my
efforts rather than the sound of a piano that has been dropped out of a
window!

Cheers,
Andy


On 27/07/2010 13:35, "longenough2002" <backshall1@bellsouth.net> wrote:

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> I tested this by setting VR1,2,3 to their midpoint, inserted a trimpot for R93
> and adjusted the pot for best scaling. It seemed to be about 40 point
> something K. 39K was the closest I had, so that's what I used. If you have
> more resistor choices (41K, 42K?) you might want to try one of those and see
> if you get better results, or even leave in a 50K trimmer.
> Don B.
> 
> --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> , Andrew
> Jury <andy@...> wrote:
>> >
>> > Hi,
>> > 
>> > Just wanted to say that I have been getting on very well with the
>> > Silonex / 39k resistor mod. The only problem is the tuning is a bit
>> > critical towards the lower end of the keyboard. Apart from that all is
>> > well and I am on my fourth successful repair.
>> > 
>> > Cheers,
>> > Andy
>> > 
>> > 
>> > 
>> > On 23 Jul 2010, at 16:31, "longenough2002" <backshall1@...>
>> > wrote:
>> > 
>>>> > > > Shucks, just noticed a note in the "files" section from gil_we
>>> > > back in Oct 2007 where he replaced the p1501 with a VTL5C3. I wonder
>>> > > if the lower temperature coefficient of the VTL5C3 makes it a better
>>> > > choice than the VTL5C2 for the tuning circuit? Some day, I gotta
>>> > > read the rest of the stuff in there.
>>> > > Don B.
>>> > >
>>> > > --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> , M Ll
>>> <f115@> wrote:
>>>> > > >
>>>> > > > Thanks for the update!
>>> > >
>>>> > > > ________________________________
>>>> > > > From: longenough2002 <backshall1@>
>>>> > > > To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
>>>> > > > Sent: Sat, June 12, 2010 8:53:50 AM
>>>> > > > Subject: [PolySix] Re: Replacement for HTV P1501 photocoupler?
>>>> > > >
>>>> > > >
>>>> > > > Got another Polysix in the shop with tuning problems. Same sort of
>>> > > thing with octaves "stretched" and it couldn't be corrected with the
>>> > > trim pots. The diode side of the photocoupler tested bad, so it was
>>> > > time to go shopping again. This time, I thought I would try one of
>>> > > the Vactrol parts, so I got a Vactec VTL5C2 from Small Bear (same
>>> > > place I got the Silonex part). I replaced R93 with 22K (up from
>>> > > 4.7K) and it seems to be working very well, so now we have a couple
>>> > > of choices for replacing the P1501.
>>>> > > >
>>>> > > > Don B.
>>>> > > >
>>>> > > >
>>> > >
>>> > > 
>> > 
>> > 
>> > [Non-text portions of this message have been removed]
>> >
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