AW: Audio Op-Amps

[Haible Juergen]

	>> Lastly, there is another bipolar dual op amp called a RC4558 that
JRC made.
	>> Used EXTENSIVELY in early
	>> Yamaha synths, mixers, cd players, and car stereos. Not a bad
part, was
	>> about 1/2 the price of the TL07x
	>> in 1984. Makes a difference: JRC rep told me Yamaha used 125,000
a WEEK!
	>
	>Yes thats interesting, the japanese manufacturers seems to be wery
found
	>of the
	>4558, its used in a lot of old Korgs and some Roland synths too!

I used to think they were using them because they were cheap (and therefore
"upgraded" everything to TL07x etc. when cloning something) - but I am not
so
sure about it anymore.
What exactly is the difference between the JRC4558 and the various other 
RC4558's ?

And what about these other RC "audio" opamps, I think RC4136 is the number ?
Strange pinout, but they aparently do a good job in Dynacord effects. Are
they
worth the trouble with the pinout ?

JH.