Would this work?

[lightningfingers]

Hello,

Anyone think this would work? (is supposed to be a compressor :wink: )



Its basically a smaller version of my orange squeezer (with a vactrol instead of the JFETs, based on a post by Mark Hammer)

Anyone wish to comment?

[bioroids]

Why dont try it on breadboard?

I think it may work, but may be on the noisy side, as it works by reducing the input signal but keepeing the transistor gain up.

Maybe you can connect the ldr to control the negative feedback (in place of the 2M2 resistor); you may need to invert the control signal for this to work, I think

Luck

Miguel

[lightningfingers]

l would, but my breadboards have a smallstone, and half a zombie chorus on them.

Maybe you can connect the ldr to control the negative feedback (in place of the 2M2 resistor); you may need to invert the control signal for this to work, I think

I never thought about that....

Cheers, :mrgreen:

[bioroids]

Also check out the flatline compressor at hollis site

http://www.hollis.co.uk/john/flatline.jpg

Regards

Miguel

[Nasse]

In theory, whatever signal source and its impedance is connected to input, forms a voltage divider with LDR. As no info what ldr is used and no idea what is the input "resistance" I think only way is to test it in real life. Might work just fine.

Maybe you could put a buffer to input, and choose a voltage divider resistor that matches the ldr spcs so you get best available control range. In some applications such voltage divider is purposely made low value resistabce to keep noise down. But anyhow I´m interested how this works. Once made a noise gate type circuit with resitor/ldr voltage divider and it worked just very very fine.

[DDD]

First, add a resistor (say, 470 Ohm) in series with LED to protect it from excessive current peaks.
Then, 1K trim is not necessary, or it should be changed with another resistance pot to adjust the circuit to particular signal source.
Also, try to connect the 'upper' terminal of LDR to the junction point of 220k and 4n7 instead of the 'left' terminal of 220k.
And I think it's necessary to add a capacitor (about 0.1-1.0uF) from the base of Q2 to ground.