[sdiy] Buchla 259a and LF13331 substitute

[Dave Leith]

Thanks everyone for all the info. I do already have some LF13331 to
experiment with.

Mark I have a question for you. You recommend the DG201 as a good
replacement (as does a cinematronics vector monitor repair guide that
I found thru internet research) What I'm puzzled about is the both
chips have Logic 0 < .8V and Logic 1 as > 2.4 The LF13331 is normally
open but the DG201 is normally closed, (DG202  normally open) What am
I missing here?

The other interesting detail from the cinematronics vector monitor
repair guide is that they say a major cause of failure (for them) with
the LF13331 is when the the -15 supply comes up faster than the +15
and they recommend a diode between pins 4 -5 of the LF13331 to
protect. I'm using a Power One supply - I wonder if this is necessary?

Dave

On 1/7/09, mark verbos <mverbos at earthlink.net> wrote:
> be careful.
>
>  I have worked on many 259s. I own one that was built by a 3rd party and
> this person used DG412s instead of LF13331Ns. In theory, these are better,
> faster, lower on resistance, but they caused little glitches that went away
> when replaced with actual LF13331Ns. I'm not saying that there's anything
> magic about those chips, just be sure to use a replacement that is similar
> spec'ed and not "better."
>
>  I recommend DG201 as a replacement in the 259. The pinout is almost the
> same, sadly a couple pins are rearranged.
>
>  Mark
>
>
>
>
>  On Jan 7, 2009, at 2:16 AM, Aaron Lanterman wrote:
>
>
> > On Jan 7, 2009, at 2:09 AM, David Ingebretsen wrote:
> >
> >
> > > This page,
> http://mysite.verizon.net/res8aiig/ICparts/ICparts.htm the
> LF13331 for sale, a bit pricey, almost $12.00 for singles, but I don't
> really have a feel for what a good price would be for one of these chips.
> > >
> > >
> > No reason I can think of to use a LF13331 when a modern DG chip will
> probably be better anyway.
> >
> > I remember Peter Grenader giving the same recommendation (IIRC).
> >
> > - Aaron
> >
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