[sdiy] starter components -- one of everything?

[Oren Leavitt]

Hi Johannes,

Sounds like you've been bit by the SynthDIY electronics bug :-)

At this point, if you are building things from existing schematics just 
buy just the parts you need when you need them.
As you build more stuff, notice what you use most often, and buy larger 
quantities of those parts. Over time, you'll build an inventory parts 
based on what use most often, and you wont blow your budget on stuff 
that you end up not using.

There are differences in the various OTA chips used - CA3080, CA3280, 
LM13700, etc...
The package pinouts are different and the circuit design will have to be 
modified to accomodate an alternate OTA.

Offset nulling provides a way to trim out small DC offsets in an op amp 
without having to load down the input pins.

Craig Anderton's book, Electronic Projects For Musicians, might be a 
good start for some of the things you want to build.

http://www.paia.com/epfm.htm

Happy SynthDIYing
Oren

Johannes Öberg wrote:
> I found a cheap surplus supplier, and now I'm wondering what OP-amps
> and OTA's are best to get for general purpose use. I see some op-amps
> feature "offset nulling". What is that?
> 
> What I'm mostly considering building are a couple of compressors,
> filters, distortions and stuff like that, and various control stuff to
> make stuff MIDI-controlled. Are those packs of 4-opamps-in-a-DIL14 a
> good idea too keep things at equal temperatures or something?
> 
> What's the difference between the different OTA:s? Can you safely
> replace one type with another in circuits, even if you don't really
> know what your doing? :-)
> 
> Also, what transistors? Are arrays generally a good idea?
> 
> (FYI, I don't know much about electronics so I'm mostly in the
> 'build-other-peoples-circuits'-stage of my sdiy career, I'm on a
> poor-student budget and I'm not exactly and audiophile. I guess I'm
> looking for best bang/buck)
> 
> 
>>2N3904 and 2N3906 transistors, > TL072 op amps
> 
> 
> Are these the cheapest, the best or both? :-) That is, why 2n3904 etc?
> (if there is a why)
>