Transistor arrays and strange opamps

[(Ian A. Vine (phone UK 0171 419 3450))]

Hi,

	I am currently looking into building a small portable synth
	based on the venerable tb303, probably with an extra oscillator
	and a few modulatin options.

	The oscillator uses a dual npn ( 2sc1583 ). I am considering using
	a quad npn chip (en2016cn) the devices are similar to 2n3904
	transistors. Anybody used the en2016cn? Any info on the 2sc1583 ?

	OK next. The filter is a transistor ladder design based on 10 devices
	all npn. THere are two dual npn's one is a 2sc1583, the other is 
	2sc2291, which I guess is a 2sc1583 except the emitters aren't
	tied together. Again I'm looking at the en2016cn. Also is there
	anything to be gained in having matched transistors throughout the
	filter ladder ?

	There are a couple of opamps I have been unable to find out anything
	about,  an6562  and ba6562a, anybody any ideas ? Of course all these
	devices could well be Roland specific.

	Just found another transistor array, the ca3046. This is a lot
	cheaper but there is the additional problem of having to connect
	the substrate to the most -ve voltage ( doesn't apply to en2016cn ).

	The RS catalogue lists a few 2sc devices all made by Toshiba if that's
	any help.

	A lot of questions I know, but hopefully someone has the knowledge,

	Thanks in advance,

Ian