MAT04 for ASM-1's

[patchell]

Scott Gravenhorst wrote:

> patchell <patchell at silcom.com> wrote:
> >
> >
> >Mantid wrote:
> >
> >> Hello fellow synth nuts,
> >> I am building some ASM-1's and am thinking of using MAT04's for the matched
> >> tranny pairs. I just happen to have a few of these in my possesion. If I
> >> was to use one MAT04 for two VCO's would I have to worry about the VCO's
> >> interacting with one another?
> >
> >    This is a question I am trying to answer myself.  However, there are other
> >ways of looking at this problem.  The MAT02 costs about twice as much as the
> >MAT04.  So, even if you toss the extra transistors in a MAT04, you are still
> >ahead.  Another posibility that I have been thinking of trying, is connect the
> >extra transistors in parrallel with the other two.  This should cut the bulk
> >resistance in half, but don't really know if this is worth the trouble.
>
> Won't there be a current sharing problem with this?  I seem to
> remember seeing an application with parallel transistors to
> increase the current handling capacity, but there were also small
> ohm resistors to help share the current more equally.  Or is
> this not going to be an issue because they are all carved out
> of the same rock?
>

    Because the transistors are matched, and thermally connected, connecting them
in parrallel would not be a problem.  But since I haven't put any serious thought
to this, I am not totally positive if the gains you would get outway any
pototential problem (problems I have not identified, but being neurotic...).

>
> >>
> >> Also, is the Moog ladder filter tranny matching method appropriate for
> >> ASM-1 VCO tranny matching.
> >> It seems that the Moog method is for trannys as diodes and the ASM -1 needs
> >> trannys matched for beta.
> >> thanks- BIll
> >
> >--
> > -Jim
> >------------------------------------------------
> >* Visit:http://www.silcom.com/~patchell/
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> >* You didn't pay enough!
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> >
> >
>
> -- Scott Gravenhorst : On The Edge, but the Edge of What?
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--
 -Jim
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* Visit:http://www.silcom.com/~patchell/
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