[sdiy] Speaking of OTAs....

[Jim Patchell]

    Availiability seems to be a key question here.

    CA3280 is a pretty darn good OTA.  But, the only company making it is
Intersil, and while it is still in production, getting them is getting harder.
I am trying to decide how many I will need to get to satisfy my lifetime needs.
Currently, the only two places I know where you can get them is Future Active
and Newark (well, they have them in stock).

    The NE5517 is made by Philips (Signetics).  Basically an LM13700.  Philips
has a pretty good reputation of not just dropping a part, but who knows.  This
part is not very easy to find here in the states, although several distributors
list in (few have it in stock).

    The LM13700N (dip version) by National, apears to be going bye-bye.

    The LM13600N (any version) by National is gone.

    The NJM13600/NJM13700 is handled by Mouser.  It is difficult to say how long
those will stay in production (I would bet that they will stay in production).
So, all of the OTA's are on pretty shakey ground.

    My preference for OTA's in audio paths is the CA3280.  I also use the
LM13700, but it depends on what it is being used for.

    -Jim

"J. Larry Hendry" wrote:

> The time has come for me to expand my newbie learning of synth circuits into
> OTAs.  I have somewhat of a grasp on op amps and can now see how valuable
> the OTA is everywhere you turn.  So, I am going to breadboard up a couple of
> circuits and play with them.
>
> Any suggestions as to the component of choice today considering ease of use,
> quality performance, and the likelihood I will still be able to buy them a
> year from now?
>
> Thanks,
> Larry Hendry
>
> ----- Original Message -----
> From: Jim Patchell <patchell at silcom.com>
> Subject: Re: [sdiy] Most widely used IC
>
> Most widely used  "important" type would have to be the OTA, with the
> CA3080 probably taking top honnors, but the list of OTA's is pretty long,
> so it is hard to say which one it might be (CA3080, CA3280, CA3060 (it was
> a tripple CA3080, I have a few of these), LM13600, LM13700, NE5517,
> SSM2020?, plus the filter IC's that are made of OTA's, like the SSM2040,
> CEM3020, CEM3050, plus many others I am sure.