[sdiy] Buchla 259 timbre circuit and op amp compensation

[Aaron Lanterman]

On May 1, 2008, at 4:54 PM, anthony wrote:

> Hey this has cleared up a sticking point for me! Just try finding  
> 3160's anywhere. What about 3140's? They aren't that much different  
> from 3130's besides having different supply voltage limitations,  
> right?
>
> What about using a mix of what you have? I have a number of  
> NTE7144's (a 3140) and RCA 307-073's (a 3130) - seems like I could  
> mix 'em together in the 259 timbre circuit. Haven't looked at that  
> schematic in a while...

I'll also note that I had another student, in the past, work on the  
259 nonlinearity as an independent study credit thing. He built it  
with 3130s, on a breadboard, with no problem.

I had him experiment with how the nonlinearity changed with the  
resistor tolerances - i.e. do you really need 1% resistors? As far as  
we could tell the sound didn't seem to change when we just put in  
random 5%s. He set up a switching network that he could just switch in  
and out different resistors.

- Aaron