[sdiy] Kraakdoos line out

[Ian Fritz]

At 08:48 AM 5/15/05, Metrophage wrote:

>I have thought about making a voltage divider, presumably at the op-amp
>output, before the transistor amplification. My concern is whether or
>not reducing the voltage will remove DC components from the signal. I
>guess this would be obvious to others who are more experienced. Also,
>the Kraakdoos circuitry is very sensitive - even adding a volume pot to
>the speaker I had to try quite a few things, as I was causing the
>circuit to cease oscillating. Probably not so much an issue with most
>audio circuits, which are designed to not be so flaky.

Thanks for the clarification.  I missed the part about needing dc 
blocking.   A big output cap should work for  that.  Maybe try something 
like  opamp out --> 1 mF cap --> 10k res --> 1k res --> gnd.  The resistor 
junction will then be at a fairly hot consumer line level and fairly well 
isolated from the opamp.

Then again, maybe you already have a good enough solution.