XR-2206

[Ajax]

http://www.exar.com/Common/Content/ProductDetails.aspx?ID=XR2206
http://www.datasheetcatalog.com/datasheets_pdf/X/R/2/2/XR2206.shtml

Why do we not just use this chip instead? I realize that it's more expensive, and that can be a huge deciding factor, but other than that, I can't for the life of me find a reason to use any other chip for oscillators (assuming I'm reading everything right).

[DGTom]

Cost is the main thing I think, you can get 14 40106s from futurlec for the cost of 1 XR-2206.

Also I think its a matter of simplicity & flexability. On 1 40106 IC you get 6 gates, to make a basic clock you only 3 or 4 additional parts, making a VCO takes a few more, but, not too many. The 40106 can also be used for all kinds of other things, logic, pulse modifiers etc.

The XR-2206 does look very cool tho, I've been meaning to get some for awhile.

Part of the fun of lunettas for me is the kick I get from turning such utilitarian, un-assuming CMOS ICs into musical beasts

[Top Top]

The other nice thing about cmos is that it is so prevalent and standardized that it is very easy to replace if one blows, very easy to find, build other people's designs, etc.

[adambee7]

Dont forget the 4069 as a good osc source. I've been using rene schmitz 4069 vco circuit. very good so i made three. granted you need the whole chip just for one osc but still very cheap. I am going to build Thomas Henry xr2206 vco as i've got a few but for a lunetta i'd go for 40106 or 4069s. But I would explore expo control aswell as linear for those. I've had good results.

[Rykhaard]

If all goes as well for me as Scott Stites / Matthias build of the CD4046 VCO for 1V/Oct tuning - I'll be moving to it for _ALL_ of my oscillators, whether they be 1V/Oct or free running. (Just started on my PCB design for my first ones. Magic Smoke though, may be coming out with them - so the rumour is so far going.)

And THIS, is a low cost 1V/oct!

[adambee7]

Ryk that's an amazing osc. Just been over to birth of a synth and read through and listened to examples. Got perf board will build now. I have some fairchild 4046s and a collection of hand matched trannies so ill post some vid up when i'm finished:D

[Psyingo]

i think using the Xr2206 would be a bit of overkill. the 2206 has facilities to generate other waveforms, but in a lunetta you really only use one, a square wave. you can use it at the front end of a lunetta, if you sum parts of the generators as CV to create melodic patterns, but i think use internally of the generation in a lunetta the 2206 is too much.
as stated before, 40106's or 4069's are used because you can get several oscillators per chip. and really, the whole thing with lunettas is that they are 'no frills' by nature! thats where the interesting sounds come from, working with a very strict, simple and limited amount of building blocks to create complex sounds.