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@bellsouth.net>
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, M Ll <f115@...> wrote:
> >
> > Thanks for the update!
>
> > ________________________________
> > From: longenough2002 <backshall1@...>
> > To: PolySix@yahoogroups.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.
> >
> >
>
>
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