Wiardgroup

What is truely shocking is that SO (small outline) SMD devices are going EOL (end of life) in 
as short as two years. SMD seem like it will have the same problem as early eight bit 
digital. The rate of change is very highly accelerated. 2708 EPROMs are still available, but 
you need an old programmer to recognize them.

It is beginning to look like the safest design strategy is to us a mix of thru hole and SMD. 
It appears DIP packs are sticking around longer than some SO chips which are already 
obsoleted.

Lead bearing technology is a know factor, while lead reduced technology is still a big 
question mark. And once again, car and motorcycles batteries and stained glasses 
windows in churches represent thousands of time more evironmental lead contribution 
that Wiard could possibly make in it's entire existance.


--- In wiardgroup@yahoogroups.com, "Gary Chang" <gchang@...> wrote:
>
> I would like to add to Doc's eloquent incites that many devices, such
> as the Sequentix P3 sequencer, (which has been a rather large success
> in the thru-hole era), could not be converted to the newer technology
> in a way that was econimically realistic for its market place - and,
> because of the EU's ban on such leaded devices being manufactured, has
> now ended production.
> 
> At the very least, conversion of the 300 series to SMD would be very
> costly - period.  Grant has already employed this technology on his
> more recent devices (1200 series) - I suspect that he will continue to
> do this in the future.
> 
> As for the "archival" 300 Series Modules that exist, I think that it
> would be safe to assume that even at twice the price for components, a
> 300 Series module is still more affordable to build today in its
> existing design than turning it into a "TBD" module, pending the
> costly and uncertain conversion to SMD, which would turn this cash cow
> into a cash drain....
> 
> that''s just my opinion - I could be wrong.
> 
> 
> gary
> 
> 
> 
> 
> 
> "drmabuce" <drmabuce@> wrote:
> >
> > Hi all
> > 
> > --- In wiardgroup@yahoogroups.com, "tom_tav" <tom_tav@> wrote:
> > >
> > > Unfortunately if you want to service an instrument somedays you will
> > sooner or later having 
> > > problems to get something else then smd parts....
> > > 
> > 
> > this is true, but the decision for a technological cottage industry is
> > anything but clear right now...
> > 
> > a few questions about surface-mount technology are stacking up in my
> > mailbox so here's my take:
> > 
> > background:
> > SMD,SMT,SOIC are all jargon for pretty-much the same thing:
> > itty bitty parts that you can move with a sneeze and don't have any
> > nice bendy wires stickin' out of 'em.
> > the wiki on this subject is pretty good  
> > http://en.wikipedia.org/wiki/Surface-mount_technology
> > These things are made for the convenience of robots and not for human
> > fingers.
> > 
> > More germane to this forum is the issue of reparability. It's true
> > that the older DIP devices will suffer from a scarcity of replacement
> > parts. But this evolutionary precipice in hardware is a bit unique in
> > that the components are virtually identical electrically but they are
> > physically much smaller.  In this way this is not like the migration
> > from tubes to discrete transistors. The scale of physical
> > miniaturization was comparable but  power environments moved from high
> > voltage unipolar to lower voltage bipolar and the active components
> > had VERY different electrical properties. 
> > SMD is optimized for mass production by automated processes. Component
> > level repairs are not part of the plan. The intention is to reduce the
> > cost of the circuitboard to the point that replacement is cheaper than
> > repair. This works pretty well for cell phones produced in production
> > runs of 50,000 units but those scales do not favor small run esoteric
> > devices. Small run SMD boards don't run cheap enough to garner the
> > advantage of being disposable and replaceable.
> > Component-level repairs to SMD are possible but significantly more
> > difficult and time consuming .  i'd contend that the profile of
> > increased risk and difficulty of SMD repair is different but
> > equivalent to the tradeoffs inherent in through-hole (DIP) (ie. easier
> > repairs but scarcer parts). In a pinch I think it is easier to adapt a
> > smaller SMD chip to a through-hole application than the reverse.
> > 
> > The wiard designs (what's on the schematic) are very durable but  the
> > technology available to realize these 'songs in solder' is in a real
> > state of flux right now.*** The consequences of the choices that face
> > Prof. Richter (and his colleagues) at this juncture are VERY serious,
> > and there is no path that offers a CLEAR advantage right now.
> > 
> > aleatoric music is way more fun than aleatoric livelihoods.
> > 
> > -doc
> > 
> > PS
> > apologies to the group for all the button-thrashing empty posts this
> > morning
> > 
> > ***
> > even  -i- don't KNOW if that pun was intended or not
> >
>