[sdiy] Buchla 259 timbre circuit and op amp compensation

[Roy J. Tellason]

On Friday 02 May 2008 17:47, anthony wrote:
> Oh I forgot to say that that was the same thing as a 3130 I guess...

You mentioned that,  I just didn't quote it.

> RCA had a whole slew of part No.s that start with 307-. The NTE catalog
> designates these as "Dynascan" parts.

So those are Dynascan part numbers,  then.  They have a "catalog"?  I'm going 
to have to look into this.  I recall older cross-references that listed lots 
of numbers but never told you where they came from or who they belonged to...

> And they can be either CMOS digital or CMOS analog (the 307-073's are the
> only example I have some of) and even bipolar analog (one is a 723 voltage
> regulator - I don't remember its part no. because it wasn't in any shape to
> salvage, but I made a mental note of it, without too much lamenting because
> I have so many 723's: metals cans,  ceramic DIP & plastic DIP...).

It's not a part I find terribly useful these days,  though I did built a 
regulator around it back around 1971 or thereabouts,  before all these 
3-terminal devices became so commonly available.  It's handy for some things,  
like making a tracking dual regulator,  boosting current up to the level you 
want,  variable voltage over a pretty wide range,  etc. but I've not really 
seen much of a need for many of those things.

> I have a few of each of the following: 307-073 (3130), 307-062 (4013),
> 307-076 (4016), 307-146 (4518), 307-167 (4030) & I also recall there being
> They all came from the same piece of precision lab gear which I'm pretty
> sure was either a DMM or a quartz thermometer/slash frequency counter. I
> think it's the former because I remember the quartz thermometer I took
> apart had nixies each with their own driver boards and I have some
> MC14543's (but the displays were LED not LCD...) 

That's one sort of part I'm kinda short on these days,  and I have a bunch of 
displays...

> that I know came out of the same piece of gear as the 307-XXX stuff. It's
> funny that there were also CMOS parts with regular part numbers on them in
> their too. I guess that makes sense. Nobody makes gear with 100% of the
> chips from the same maker. But most of the RCA CMOS chips had the normal
> chip part designators on them instead of the wacky 307-XXX "Dynascan"
> numbers. 

Hm.  Where did you find this stuff?

> A lot of parts start with 221-XXX. I have nine NOS LM3900's that have
> 221-235 on them. I think I got them in Jim-Pak packs of 3. I probably
> wouldn't have bought them if I hadn't had an LM3900 that I scavanged from
> an old acoustic coupler modem (of all things - actually that modem yielded
> up lots of cool parts and I used the case to put two joystick controllers
> in to make a "Space Box" like Grant Richter's which is as of yet
> unfinished...). I have a few other random parts with no.'s that begin with
> 221- but I havn't found cross-refs. or NTE parts for them to compare.

Old modems do indeed yield lots of good parts.  I haven't torn apart any of 
mine yet,  but there were plenty of other ones (internals mostly) that gave 
up a bunch of useful stuff.  Those little transformers,  tiny speakers,  
typically an LM386 chip,  other stuff sometimes.

Never used an LM3900 here yet.

> Oh the things you collect when you've been tearing stuff apart for about 26
> years.

I've been at it a bit longer than that I think.

> Sometimes I have fits and no piece of electronics gear in the house 
> is safe.

I don't mess with stuff I use,  and I have plenty of stuff to scrap out,  
mostly.

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James 
M Dakin