Discussion about the Korg PolySix synthesizer

Now that my KLM-367 seems fairly happy, I've turned to the KLM-366B to see what's up with the stretched tuning. Playing up an octave seems to go 13 or so semitones instead of 12. VR3 will improve this a bit if it is cranked fully clockwise, but not enough to solve the problem. VR2 doesn't do anything at all. The culprit seems to be the PC1 photocoupler. I did a quick check on the web and didn't see any except at the big parts wholesalers where there is either a $200 minimum order or minimum 1000 pieces or something like that. On Ebay all I can seem to find are transistor-output type devices, not the old style photo-resistor output like the P1501. Does anyone know where to get one of these, or what a reasonable replacement might be?
Thanks,
Don B.

Did you try vactrol vtl series?

--- On Tue, 2/16/10, longenough2002 <backshall1@bellsouth.net> wrote:

From: longenough2002 <backshall1@bellsouth.net>
Subject: [PolySix] Replacement for HTV P1501 photocoupler?
To: PolySix@yahoogroups.com
Date: Tuesday, February 16, 2010, 4:49 PM

Now that my KLM-367 seems fairly happy, I've turned to the KLM-366B to see what's up with the stretched tuning. Playing up an octave seems to go 13 or so semitones instead of 12. VR3 will improve this a bit if it is cranked fully clockwise, but not enough to solve the problem. VR2 doesn't do anything at all. The culprit seems to be the PC1 photocoupler. I did a quick check on the web and didn't see any except at the big parts wholesalers where there is either a $200 minimum order or minimum 1000 pieces or something like that. On Ebay all I can seem to find are transistor-output type devices, not the old style photo-resistor output like the P1501. Does anyone know where to get one of these, or what a reasonable replacement might be?
Thanks,
Don B.



------------------------------------

PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups Links








[Non-text portions of this message have been removed]

Vactrol VTL series does look good. I need to poke around the web some more
to find a good supplier. Silonex also seems to make a few of these things,
but not many sources for those either.
Thanks,
Don B.

_____

From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
Mike Borish
Sent: Tuesday, February 16, 2010 7:11 PM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Replacement for HTV P1501 photocoupler?




Did you try vactrol vtl series?

--- On Tue, 2/16/10, longenough2002 <backshall1@bellsout
<mailto:backshall1%40bellsouth.net> h.net> wrote:

From: longenough2002 <backshall1@bellsout
<mailto:backshall1%40bellsouth.net> h.net>
Subject: [PolySix] Replacement for HTV P1501 photocoupler?
To: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
Date: Tuesday, February 16, 2010, 4:49 PM

Now that my KLM-367 seems fairly happy, I've turned to the KLM-366B to see
what's up with the stretched tuning. Playing up an octave seems to go 13 or
so semitones instead of 12. VR3 will improve this a bit if it is cranked
fully clockwise, but not enough to solve the problem. VR2 doesn't do
anything at all. The culprit seems to be the PC1 photocoupler. I did a quick
check on the web and didn't see any except at the big parts wholesalers
where there is either a $200 minimum order or minimum 1000 pieces or
something like that. On Ebay all I can seem to find are transistor-output
type devices, not the old style photo-resistor output like the P1501. Does
anyone know where to get one of these, or what a reasonable replacement
might be?
Thanks,
Don B.

------------------------------------

PolySix "Digiest" Page: http://www.acc
<http://www.acc.umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
Links

[Non-text portions of this message have been removed]






[Non-text portions of this message have been removed]

Allied Electronics

--- On Tue, 2/16/10, backshall1 (dsl) <backshall1@bellsouth.net> wrote:

From: backshall1 (dsl) <backshall1@bellsouth.net>
Subject: RE: [PolySix] Replacement for HTV P1501 photocoupler?
To: PolySix@yahoogroups.com
Date: Tuesday, February 16, 2010, 7:25 PM

Vactrol VTL series does look good. I need to poke around the web some more
to find a good supplier. Silonex also seems to make a few of these things,
but not many sources for those either.
Thanks,
Don B.

  _____ 

From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
Mike Borish
Sent: Tuesday, February 16, 2010 7:11 PM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Replacement for HTV P1501 photocoupler?


 

Did you try vactrol vtl series?

--- On Tue, 2/16/10, longenough2002 <backshall1@bellsout
<mailto:backshall1%40bellsouth.net> h.net> wrote:

From: longenough2002 <backshall1@bellsout
<mailto:backshall1%40bellsouth.net> h.net>
Subject: [PolySix] Replacement for HTV P1501 photocoupler?
To: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
Date: Tuesday, February 16, 2010, 4:49 PM

Now that my KLM-367 seems fairly happy, I've turned to the KLM-366B to see
what's up with the stretched tuning. Playing up an octave seems to go 13 or
so semitones instead of 12. VR3 will improve this a bit if it is cranked
fully clockwise, but not enough to solve the problem. VR2 doesn't do
anything at all. The culprit seems to be the PC1 photocoupler. I did a quick
check on the web and didn't see any except at the big parts wholesalers
where there is either a $200 minimum order or minimum 1000 pieces or
something like that. On Ebay all I can seem to find are transistor-output
type devices, not the old style photo-resistor output like the P1501. Does
anyone know where to get one of these, or what a reasonable replacement
might be?
Thanks,
Don B.

------------------------------------

PolySix "Digiest" Page: http://www.acc
<http://www.acc.umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
Links

[Non-text portions of this message have been removed]






[Non-text portions of this message have been removed]



------------------------------------

PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups Links








[Non-text portions of this message have been removed]

Lot's of them at small bear too:
http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photocouplers

<http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photocouplers>Let
us know how that works out. Mine has the same issue but I haven't had time
to debug it.

Jed

On Tue, Feb 16, 2010 at 5:44 PM, Mike Borish <mborish_2000@yahoo.com> wrote:

>
>
> Allied Electronics
>
> --- On Tue, 2/16/10, backshall1 (dsl) <backshall1@bellsouth.net<backshall1%40bellsouth.net>>
> wrote:
>
> From: backshall1 (dsl) <backshall1@bellsouth.net<backshall1%40bellsouth.net>
> >
> Subject: RE: [PolySix] Replacement for HTV P1501 photocoupler?
> To: PolySix@yahoogroups.com <PolySix%40yahoogroups.com>
> Date: Tuesday, February 16, 2010, 7:25 PM
>
>
> Vactrol VTL series does look good. I need to poke around the web some more
> to find a good supplier. Silonex also seems to make a few of these things,
> but not many sources for those either.
> Thanks,
> Don B.
>
> _____
>
> From: PolySix@yahoogroups.com <PolySix%40yahoogroups.com> [mailto:
> PolySix@yahoogroups.com <PolySix%40yahoogroups.com>] On Behalf Of
> Mike Borish
> Sent: Tuesday, February 16, 2010 7:11 PM
> To: PolySix@yahoogroups.com <PolySix%40yahoogroups.com>
> Subject: Re: [PolySix] Replacement for HTV P1501 photocoupler?
>
>
>
> Did you try vactrol vtl series?
>
> --- On Tue, 2/16/10, longenough2002 <backshall1@bellsout
> <mailto:backshall1%40bellsouth.net <backshall1%2540bellsouth.net>> h.net>
> wrote:
>
> From: longenough2002 <backshall1@bellsout
> <mailto:backshall1%40bellsouth.net <backshall1%2540bellsouth.net>> h.net>
> Subject: [PolySix] Replacement for HTV P1501 photocoupler?
> To: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com<PolySix%2540yahoogroups.com>>
> .com
> Date: Tuesday, February 16, 2010, 4:49 PM
>
> Now that my KLM-367 seems fairly happy, I've turned to the KLM-366B to see
> what's up with the stretched tuning. Playing up an octave seems to go 13 or
> so semitones instead of 12. VR3 will improve this a bit if it is cranked
> fully clockwise, but not enough to solve the problem. VR2 doesn't do
> anything at all. The culprit seems to be the PC1 photocoupler. I did a
> quick
> check on the web and didn't see any except at the big parts wholesalers
> where there is either a $200 minimum order or minimum 1000 pieces or
> something like that. On Ebay all I can seem to find are transistor-output
> type devices, not the old style photo-resistor output like the P1501. Does
> anyone know where to get one of these, or what a reasonable replacement
> might be?
> Thanks,
> Don B.
>
> ------------------------------------
>
> PolySix "Digiest" Page: http://www.acc
> <http://www.acc.umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
> Links
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
> ------------------------------------
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups
> Links
>
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]

Allied has a good selection and good prices ($1.78 for Silonex NSL-32) but
there is a $5 handling fee for orders under $25. Small Bear has the NSL-32
for $4 with no minimum and he takes Paypal, and you have to love a site
dedicated to guitar stomp boxes and the "production of loud, growly, raucous
instrumental noise". I'm not sure if I should spend more time going over the
specs for the various choices or just assume that I might have to tweak R93
and/or R85. I guess I'll never know for sure until I order something and try
it out.
Don B.

-----Original Message-----
From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
Jed Jorgensen
Sent: Tuesday, February 16, 2010 11:33 PM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Replacement for HTV P1501 photocoupler?

Lot's of them at small bear too:
http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photocou
plers

<http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photoco
uplers>Let
us know how that works out. Mine has the same issue but I haven't had time
to debug it.

Jed

On Tue, Feb 16, 2010 at 5:44 PM, Mike Borish <mborish_2000@yahoo.com> wrote:

>
>
> Allied Electronics
>
> --- On Tue, 2/16/10, backshall1 (dsl)
<backshall1@bellsouth.net<backshall1%40bellsouth.net>>
> wrote:
>
> From: backshall1 (dsl)
<backshall1@bellsouth.net<backshall1%40bellsouth.net>
> >
> Subject: RE: [PolySix] Replacement for HTV P1501 photocoupler?
> To: PolySix@yahoogroups.com <PolySix%40yahoogroups.com>
> Date: Tuesday, February 16, 2010, 7:25 PM
>
>
> Vactrol VTL series does look good. I need to poke around the web some more
> to find a good supplier. Silonex also seems to make a few of these things,
> but not many sources for those either.
> Thanks,
> Don B.
>
> _____
>
> From: PolySix@yahoogroups.com <PolySix%40yahoogroups.com> [mailto:
> PolySix@yahoogroups.com <PolySix%40yahoogroups.com>] On Behalf Of
> Mike Borish
> Sent: Tuesday, February 16, 2010 7:11 PM
> To: PolySix@yahoogroups.com <PolySix%40yahoogroups.com>
> Subject: Re: [PolySix] Replacement for HTV P1501 photocoupler?
>
>
>
> Did you try vactrol vtl series?
>
> --- On Tue, 2/16/10, longenough2002 <backshall1@bellsout
> <mailto:backshall1%40bellsouth.net <backshall1%2540bellsouth.net>> h.net>
> wrote:
>
> From: longenough2002 <backshall1@bellsout
> <mailto:backshall1%40bellsouth.net <backshall1%2540bellsouth.net>> h.net>
> Subject: [PolySix] Replacement for HTV P1501 photocoupler?
> To: PolySix@yahoogroups
<mailto:PolySix%40yahoogroups.com<PolySix%2540yahoogroups.com>>
> .com
> Date: Tuesday, February 16, 2010, 4:49 PM
>
> Now that my KLM-367 seems fairly happy, I've turned to the KLM-366B to see
> what's up with the stretched tuning. Playing up an octave seems to go 13
or
> so semitones instead of 12. VR3 will improve this a bit if it is cranked
> fully clockwise, but not enough to solve the problem. VR2 doesn't do
> anything at all. The culprit seems to be the PC1 photocoupler. I did a
> quick
> check on the web and didn't see any except at the big parts wholesalers
> where there is either a $200 minimum order or minimum 1000 pieces or
> something like that. On Ebay all I can seem to find are transistor-output
> type devices, not the old style photo-resistor output like the P1501. Does
> anyone know where to get one of these, or what a reasonable replacement
> might be?
> Thanks,
> Don B.
>
> ------------------------------------
>
> PolySix "Digiest" Page: http://www.acc
> <http://www.acc.umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
> Links
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
> ------------------------------------
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups
> Links
>
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]



------------------------------------

PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups
Links

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.

-----Original Message-----
From: backshall1 (dsl) [mailto:backshall1@bellsouth.net]
Sent: Wednesday, February 17, 2010 8:32 AM
To: 'PolySix@yahoogroups.com'
Subject: RE: [PolySix] Replacement for HTV P1501 photocoupler?


Allied has a good selection and good prices ($1.78 for Silonex NSL-32) but
there is a $5 handling fee for orders under $25. Small Bear has the NSL-32
for $4 with no minimum and he takes Paypal, and you have to love a site
dedicated to guitar stomp boxes and the "production of loud, growly, raucous
instrumental noise". I'm not sure if I should spend more time going over the
specs for the various choices or just assume that I might have to tweak R93
and/or R85. I guess I'll never know for sure until I order something and try
it out.
Don B.

-----Original Message-----
From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
Jed Jorgensen
Sent: Tuesday, February 16, 2010 11:33 PM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Replacement for HTV P1501 photocoupler?

Lot's of them at small bear too:
http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photocou
plers

<http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photoco
uplers>Let
us know how that works out. Mine has the same issue but I haven't had time
to debug it.

Jed

On Tue, Feb 16, 2010 at 5:44 PM, Mike Borish <mborish_2000@yahoo.com> wrote:

>
>
> Allied Electronics
>
> --- On Tue, 2/16/10, backshall1 (dsl)
<backshall1@bellsouth.net<backshall1%40bellsouth.net>>
> wrote:
>
> From: backshall1 (dsl)
<backshall1@bellsouth.net<backshall1%40bellsouth.net>
> >
> Subject: RE: [PolySix] Replacement for HTV P1501 photocoupler?
> To: PolySix@yahoogroups.com <PolySix%40yahoogroups.com>
> Date: Tuesday, February 16, 2010, 7:25 PM
>
>
> Vactrol VTL series does look good. I need to poke around the web some more
> to find a good supplier. Silonex also seems to make a few of these things,
> but not many sources for those either.
> Thanks,
> Don B.
>
> _____
>
> From: PolySix@yahoogroups.com <PolySix%40yahoogroups.com> [mailto:
> PolySix@yahoogroups.com <PolySix%40yahoogroups.com>] On Behalf Of
> Mike Borish
> Sent: Tuesday, February 16, 2010 7:11 PM
> To: PolySix@yahoogroups.com <PolySix%40yahoogroups.com>
> Subject: Re: [PolySix] Replacement for HTV P1501 photocoupler?
>
>
>
> Did you try vactrol vtl series?
>
> --- On Tue, 2/16/10, longenough2002 <backshall1@bellsout
> <mailto:backshall1%40bellsouth.net <backshall1%2540bellsouth.net>> h.net>
> wrote:
>
> From: longenough2002 <backshall1@bellsout
> <mailto:backshall1%40bellsouth.net <backshall1%2540bellsouth.net>> h.net>
> Subject: [PolySix] Replacement for HTV P1501 photocoupler?
> To: PolySix@yahoogroups
<mailto:PolySix%40yahoogroups.com<PolySix%2540yahoogroups.com>>
> .com
> Date: Tuesday, February 16, 2010, 4:49 PM
>
> Now that my KLM-367 seems fairly happy, I've turned to the KLM-366B to see
> what's up with the stretched tuning. Playing up an octave seems to go 13
or
> so semitones instead of 12. VR3 will improve this a bit if it is cranked
> fully clockwise, but not enough to solve the problem. VR2 doesn't do
> anything at all. The culprit seems to be the PC1 photocoupler. I did a
> quick
> check on the web and didn't see any except at the big parts wholesalers
> where there is either a $200 minimum order or minimum 1000 pieces or
> something like that. On Ebay all I can seem to find are transistor-output
> type devices, not the old style photo-resistor output like the P1501. Does
> anyone know where to get one of these, or what a reasonable replacement
> might be?
> Thanks,
> Don B.
>
> ------------------------------------
>
> PolySix "Digiest" Page: http://www.acc
> <http://www.acc.umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
> Links
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
> ------------------------------------
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups
> Links
>
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]



------------------------------------

PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups
Links

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.
>

Thanks for the update!



________________________________
From: longenough2002 <backshall1@bellsouth.net>
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.

--- 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.
>






[Non-text portions of this message have been removed]

> 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.
>
>

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.
> >
> >
>
>

[Non-text portions of this message have been removed]

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, 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, 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.
> > >
> > >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>

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:

>
>
>
>
>
> 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]

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]
>

I had to change out the opto in my unit. There's a text file in the "Files"
section of the group website that has the following advice, which I
followed:


From a user (rhe solution refers to the problem of not being able to
get correct scaling of the Polysix keyboard):


I wanted to let you know that I've finally managed to repair my
Precious (Polysix). It was indeed the opto resistor, the PC-1, that
was faulty. It was suggested to me that I replace the old mysterious
PC-1 component with a VTL5C3 and change R93 from 4k7 to 1k2 (to get
the VTL5C3 working properly). I did and then the synth was as good
as new!

Appearently, the PC-1 is what stabilizes the expo-converter circuit.
If it's broken, the circuit can't manage to keep the synth in tune
as the voltages vary (which is especially noticeable during the time
the machine is warming up).

Thanks for the help!

On Tue, May 10, 2011 at 3:50 PM, ltern_te <ninonine@xs4all.nl> wrote:

>
>
> 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]
> >
>
>
>


[Non-text portions of this message have been removed]

Hi,

I¹ve always used the Siliconix NSL32 and a 39K resistor at position R93 and
got very good results. Best of all they sell then Œoff the shelf¹ at
Farnell, which considerably saves time in sourcing them.

Cheers,
Andy

On 10/05/2011 23:50, "ltern_te" <ninonine@xs4all.nl> wrote:

>
>
>
>
>
> 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 <mailto:PolySix%40yahoogroups.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>
>>> <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> <mailto:PolySix%40yahoogroups.com> ,
M Ll
>>>>> > >>> <f115@> wrote:
>>>>>>>>> > >>>> > > >
>>>>>>>>> > >>>> > > > Thanks for the update!
>>>>>>> > >>> > >
>>>>>>>>> > >>>> > > > ________________________________
>>>>>>>>> > >>>> > > > From: longenough2002 <backshall1@>
>>>>>>>>> > >>>> > > > To: PolySix@yahoogroups.com
>>>>>>>>> <mailto:PolySix%40yahoogroups.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]
>> >
>
>
>
>
>



[Non-text portions of this message have been removed]

Hi Simon,
I haven't needed to replace another bad photocoupler so I haven't had a
chance to try a VTL5C3. I also haven't noticed any problems with tuning with
the VTL5C2 so I don't think there is a big enough difference to cause any
trouble. It is important to note the wide variation of values used for R93,
depending on which replacement you use for the P1501. It is always best to
put in a 50K trimpot, set the tuning controls to mid-point, and set the
trimpot for best initial tuning.

As for "how" to do the replacement. I assume you are wondering how to put a
4-wire radial-lead component into a 6-pin DIP slot. Well, I guess it is
really a 5-pin slot, since pin 5 doesn't exist. Going counter-clockwise,
pins 1,2,3 go down the left side, and pins 4 and 6 go up the right side. Pin
5 is a blank space. Also, pin 3 is not connected to anything, so both old
and new components are really 4-pin devices.

On the P1501, the KLM-366 schematic shows that pins 1,2 are the anode and
cathode of the LED, and pins 4,6 are the photo-resistor. You'll need the
pin-out diagram for whatever part you are using as a replacement to see
which two wires are the LED and which are the resistor, and what the
polarity of the LED is. Once you are certain which wire goes where, heat up
the soldering iron and get to work.

Don B.

_____

From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
Andrew Jury
Sent: Wednesday, May 11, 2011 5:09 AM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Re: Replacement for HTV P1501 photocoupler?




Hi,

I�ve always used the Siliconix NSL32 and a 39K resistor at position R93 and
got very good results. Best of all they sell then �off the shelf� at
Farnell, which considerably saves time in sourcing them.

Cheers,
Andy

On 10/05/2011 23:50, "ltern_te" <ninonine@xs4all.nl
<mailto:ninonine%40xs4all.nl> > wrote:

>
>
>
>
>
> 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 <mailto:PolySix%40yahoogroups.com>

<mailto:PolySix%40yahoogroups.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>

<mailto:PolySix%40yahoogroups.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>

>>>>>>> <mailto:PolySix%40yahoogroups.com>

<mailto:PolySix%40yahoogroups.com> ,
M Ll

>>>>> > >>> <f115@> wrote:
>>>>>>>>> > >>>> > > >
>>>>>>>>> > >>>> > > > Thanks for the update!
>>>>>>> > >>> > >
>>>>>>>>> > >>>> > > > ________________________________
>>>>>>>>> > >>>> > > > From: longenough2002 <backshall1@>
>>>>>>>>> > >>>> > > > To: PolySix@yahoogroups.com

<mailto:PolySix%40yahoogroups.com>

>>>>>>>>> <mailto:PolySix%40yahoogroups.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]
>> >
>
>
>
>
>

[Non-text portions of this message have been removed]






[Non-text portions of this message have been removed]

Hi Don,

Thank you for your helpful response. Managed to get the VTL5C2 part ordered and will start the repairs on the polysix soon. It has a tuning problem and cannot be corrected anymore by calibrating. It also has had the LFO leaking into the VCO,s but that has already been fixed. Quite challenging figuring out how the schematics work without looking on the voiceboard, figured out that way that pin 3 has nc. Korg doesnt seem to have sharper pictures of the schematics. Will post the results back later here.. Cheers!

Simon

--- In PolySix@yahoogroups.com, "backshall1 \(dsl\)" <backshall1@...> wrote:
>
> Hi Simon,
> I haven't needed to replace another bad photocoupler so I haven't had a
> chance to try a VTL5C3. I also haven't noticed any problems with tuning with
> the VTL5C2 so I don't think there is a big enough difference to cause any
> trouble. It is important to note the wide variation of values used for R93,
> depending on which replacement you use for the P1501. It is always best to
> put in a 50K trimpot, set the tuning controls to mid-point, and set the
> trimpot for best initial tuning.
>
> As for "how" to do the replacement. I assume you are wondering how to put a
> 4-wire radial-lead component into a 6-pin DIP slot. Well, I guess it is
> really a 5-pin slot, since pin 5 doesn't exist. Going counter-clockwise,
> pins 1,2,3 go down the left side, and pins 4 and 6 go up the right side. Pin
> 5 is a blank space. Also, pin 3 is not connected to anything, so both old
> and new components are really 4-pin devices.
>
> On the P1501, the KLM-366 schematic shows that pins 1,2 are the anode and
> cathode of the LED, and pins 4,6 are the photo-resistor. You'll need the
> pin-out diagram for whatever part you are using as a replacement to see
> which two wires are the LED and which are the resistor, and what the
> polarity of the LED is. Once you are certain which wire goes where, heat up
> the soldering iron and get to work.
>
> Don B.
>
> _____
>
> From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
> Andrew Jury
> Sent: Wednesday, May 11, 2011 5:09 AM
> To: PolySix@yahoogroups.com
> Subject: Re: [PolySix] Re: Replacement for HTV P1501 photocoupler?
>
>
>
>
> Hi,
>
> I¹ve always used the Siliconix NSL32 and a 39K resistor at position R93 and
> got very good results. Best of all they sell then Œoff the shelf¹ at
> Farnell, which considerably saves time in sourcing them.
>
> Cheers,
> Andy
>
> On 10/05/2011 23:50, "ltern_te" <ninonine@...
> <mailto:ninonine%40xs4all.nl> > wrote:
>
> >
> >
> >
> >
> >
> > 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 <mailto:PolySix%40yahoogroups.com>
> <mailto:PolySix%40yahoogroups.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>
> <mailto:PolySix%40yahoogroups.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>
> >>>>>>> <mailto:PolySix%40yahoogroups.com>
> <mailto:PolySix%40yahoogroups.com> ,
> M Ll
> >>>>> > >>> <f115@> wrote:
> >>>>>>>>> > >>>> > > >
> >>>>>>>>> > >>>> > > > Thanks for the update!
> >>>>>>> > >>> > >
> >>>>>>>>> > >>>> > > > ________________________________
> >>>>>>>>> > >>>> > > > From: longenough2002 <backshall1@>
> >>>>>>>>> > >>>> > > > To: PolySix@yahoogroups.com
> <mailto:PolySix%40yahoogroups.com>
> >>>>>>>>> <mailto:PolySix%40yahoogroups.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]
> >> >
> >
> >
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

Hi Don,

I've finally found the time and finished repairing. I needed to put abt 9 k on the trimpot placed on the R93 location for a good stability in tuning for the Polysix again. All in tune now between lower and upper C's. I used the VTL5C2 replacement. Thank you and all for contributing to this subject, this was a great help. Cheers!

Simon

--- In PolySix@yahoogroups.com, "backshall1 \(dsl\)" <backshall1@...> wrote:
>
> Hi Simon,
> I haven't needed to replace another bad photocoupler so I haven't had a
> chance to try a VTL5C3. I also haven't noticed any problems with tuning with
> the VTL5C2 so I don't think there is a big enough difference to cause any
> trouble. It is important to note the wide variation of values used for R93,
> depending on which replacement you use for the P1501. It is always best to
> put in a 50K trimpot, set the tuning controls to mid-point, and set the
> trimpot for best initial tuning.
>
> As for "how" to do the replacement. I assume you are wondering how to put a
> 4-wire radial-lead component into a 6-pin DIP slot. Well, I guess it is
> really a 5-pin slot, since pin 5 doesn't exist. Going counter-clockwise,
> pins 1,2,3 go down the left side, and pins 4 and 6 go up the right side. Pin
> 5 is a blank space. Also, pin 3 is not connected to anything, so both old
> and new components are really 4-pin devices.
>
> On the P1501, the KLM-366 schematic shows that pins 1,2 are the anode and
> cathode of the LED, and pins 4,6 are the photo-resistor. You'll need the
> pin-out diagram for whatever part you are using as a replacement to see
> which two wires are the LED and which are the resistor, and what the
> polarity of the LED is. Once you are certain which wire goes where, heat up
> the soldering iron and get to work.
>
> Don B.
>
> _____
>
> From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
> Andrew Jury
> Sent: Wednesday, May 11, 2011 5:09 AM
> To: PolySix@yahoogroups.com
> Subject: Re: [PolySix] Re: Replacement for HTV P1501 photocoupler?
>
>
>
>
> Hi,
>
> I¹ve always used the Siliconix NSL32 and a 39K resistor at position R93 and
> got very good results. Best of all they sell then Œoff the shelf¹ at
> Farnell, which considerably saves time in sourcing them.
>
> Cheers,
> Andy
>
> On 10/05/2011 23:50, "ltern_te" <ninonine@...
> <mailto:ninonine%40xs4all.nl> > wrote:
>
> >
> >
> >
> >
> >
> > 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 <mailto:PolySix%40yahoogroups.com>
> <mailto:PolySix%40yahoogroups.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>
> <mailto:PolySix%40yahoogroups.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>
> >>>>>>> <mailto:PolySix%40yahoogroups.com>
> <mailto:PolySix%40yahoogroups.com> ,
> M Ll
> >>>>> > >>> <f115@> wrote:
> >>>>>>>>> > >>>> > > >
> >>>>>>>>> > >>>> > > > Thanks for the update!
> >>>>>>> > >>> > >
> >>>>>>>>> > >>>> > > > ________________________________
> >>>>>>>>> > >>>> > > > From: longenough2002 <backshall1@>
> >>>>>>>>> > >>>> > > > To: PolySix@yahoogroups.com
> <mailto:PolySix%40yahoogroups.com>
> >>>>>>>>> <mailto:PolySix%40yahoogroups.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]
> >> >
> >
> >
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>