Thanks for the update!
________________________________
From: longenough2002 <
backshall1@bellsouth.net>
To:
PolySix@yahoogroups.comSent: 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.
--- In PolySix@yahoogroups.com, "backshall1 \(dsl\)" <backshall1@...> wrote:
>
>
> Took a little time off from the Polysix, part sanity break and part getting
> caught up on some other projects. Unfortunately, two of them were Poly-61
> synths, more Victims of Varta. Anyway, the Silonex NSL-32 from Small Bear is
> installed and I replaced R93 with a 39K resistor (up from 4.7K) to get it in
> the right tuning range. Works great, sounds great. With the 4.7K ohm in, I
> got more or less microtonal tuning across the keyboard. Interesting, but not
> what I was looking for. The NSL-32 isn't a DIP chip like the P1501. It's a
> little barrel with two wires out each end, diode on one end and
> photoresistor on the other. The negative pin of the IR diode is marked with
> a little white dot.
> I thought this might be the last major malfunction for this synth, but no. I
> just noticed that patches A6 and C6 won't save the MG Frequency setting in
> memory. When you recall these patches, MG Freq is set at max. Bizarre. I
> hate to think that I might have to test every parameter of every patch. The
> "6" button isn't working very well so I guess I should clean that up first.
>
> Don B.
>
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