ba662. What is the thingy on the end??

[Paul Schreiber]

FIY:

All ICs that start with BA are from Rohm. I have some Rohm catalogs.

Paul Schreiber
Synthesis Technology


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From: 	Rob01[SMTP:cyborg0 at midwest.net]
Sent: 	Wednesday, May 28, 1997 3:57 PM
To: 	synth-diy; x0x at synthcom.com
Subject: 	ba662. What is the thingy on the end??

Well, i have finally traced back what is the problem with my sh101. It
seems as though the signal from the cem3340 wasnt getting to the filter..
unfortunately, i think i fried the cem too, but thats no biggie. It makes
its waveforms..

Anyway, strange thing, the ba662 is kinda weird. In the schematic, they
show it as looking like an OTA in the first section, but the last few pins
look almost like a symbol for a 741 BUT it only works off of a gnd
potential?? Or are they assuming that, since they are both in the same
package, that the -6.33 and -5 volts sources are connected to it? Im trying
to get a better understanding of this thing, cuz this may also be
intermittently faulty and i know they are damn near impossible to get any
more. I know i could prolly just substitute a regular joe blow OTA and
modify the circuit a bit, but i want to know more about it.

Has anyone noticed exactly how many different VCA configs there are for the
ba662? kinda unusual. I guess they were used for filters too in some of the
other sh series. Anyone who would like to discuss this with me please do
so.

                  Rob01
             Zeros & Ones
The Mind Controls the Machine 
The Machine Controls the Body