[sdiy] Question about LFOs

[Magnus Danielson]

David G. Dixon skrev:
>> I have a total of six MS-20 style LFOs in two triple modules. After some
>> time using them I beefed-up the variable ramp output from +/- 2.5V to
>> +/- 5V on all LFOs in one module just to see how often it would be
>> useful and ended up doing the other one too. Love the circuit, it's
>> simple, repeatable and flexible plus I use the variable ramp pretty much
>> ALL the time and would be lost without it.
> 
> Thanks for the excellent response (you too, Magnus)!  Now, I'm wondering: Is
> there some reason why you've chosen JFETs over diodes for the wave-shaping
> integrator?  Both circuits behave equally well in simulation.  Is there some
> problem lurking in the latter which my little noobie brain hasn't thought
> of?

The only issue I could think of is that the rise/fall factor could shift 
frequency if diodes are not matched. However, considering the 
not-so-high-precission frequency setting I think you are home safe with 
a simpler diode setup.

One way to get less newbie is to build it and if not content with it, 
try to improve it. Make a prototype and take it for a test-drive...

Get used to prototyping smaller projects... good way to learn.

Cheers,
Magnus