Hi Don/ Andy and thanks for your advice and feedback,
Maybe a dummy question but how does one replace the P1501 with a VTL5CX ? Btw. did anyone find out already if its better to use a VTL5C2 or VTL5C3 replacement?
Thanks for the answer(s) in advance.
Simon
--- In PolySix@yahoogroups.com, Andrew Jury <andy@...> wrote:
>
> 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@...> wrote:
>
> >
> >
> >
> >
> >
> > 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]
> >> >
> >
> >
> >
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
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