[sdiy] BA718 and other obsolete parts..

[Scott Stites]

Hi Seb,

I used MN5218's, but I can't recall the source for them offhand, and I've
gotta leave here on a biz trip in a bit.

But, a dig through my notes brought up these past SDIY list posts from Mike
Irwin:

===
"Regarding substitutions, most of the original Japanese parts are still
available, including the different transistors, the MN3207 (and the
companion MN3102 driver) are about as mainstream as it gets with BBD's,
relatively easy to find compared with ther BBDs, the NE570/571 compander
is also a mainstream part. Parts warehouses that cater to the consumer
electronics repair industry usually have these (check Main Electronic
Supply in  Vancouver or www.bdent.com). The single supply op amp used in
the clock circuit (IIRC a BA718) may be hard to find, I tried several
single-supply op amps with better specs (including TLC272) but achieved
the best results with a lowly LM358."

And..

"Not much difference at all between 570/571, NE/SE/SA for normal
applications. The 571 is the economy version with less tight specs than
the 570 (also has a lower max supply rating than the 570 so be careful)."
===

One final note.  The DC-2 schematic has a mistake that will make the thing
shriek instead of produce chorus if you follow it:

The unused section of the first NE570 has pins 9, 10 and 11 connected
together.  Leave pins 10 and 11 connected together, but DO NOT connect pin 9
to them - leave it unconnected.  This is another thing Mike Irwin figured
out, too....

Everything else on the schematic worked out fine, though.

Good luck!
Scott

----- Original Message -----
From: "Seb Francis" <seb at burnit.co.uk>
To: "Synth DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Sunday, June 19, 2005 3:01 PM
Subject: [sdiy] BA718 and other obsolete parts..


> Hi,
>
> I'm trying to recreate the Boss DC-2 Dimension C chorus circuit from the
> schematic but I'm having a bit of trouble getting the right parts.
>
> I'm thinking it's ok to use an NE571 instead of the NE570
> And I've read that a TL072 can be used instead of the M5218L
>
> But I'm stuck on what to use for the BA718 opamps ..  does anyone have a
> datasheet about this opamp, or a recommendation of an equivalent?
>
> Thanks in advance,
> Seb
>
>