Joined: Nov 22, 2005
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|Posted: Tue Aug 15, 2006 2:15 am Post subject:
ssm2018 compressor shematic needs more controlls
I got this schematic from a book. The design is quite simple, the signal goes through the vca, is been rectified, a cv is generated, that cv controlls the gain.
OK. What i don´t understand is how threshold, ratio and the timing is worked out here. The pot P3, right hand side in the middle sets the gain for the cv signal. The text sais this determines the threshold. P4 is supposed to controll the ratio between 1:2 and 1:10. Timing they say attack max 2ms, release 1,5sec.
I´m not really getting this. If p3 sets the threshold, that is a soft knee design, so the compression works from the lowest signal on with rising ratio, right?
P4, they call it ratio looks to me like the attack contoll.
What i want to have is the usual flexibilities you need to get those pumping grooves.
So i want to controll threshold, ratio, if possible soft or hard knee as well as attack and release.
Attack/release, thats what we call a lag generator. So i guess since that cv-in of the 2018 is a high impedance point, r14 could be replaced with a pot and diode leading back to the out of ic2/2. Independant rise/fall.
But if those timings really controll the ratio as well than i´m not on the right track.
I thought something like this: Threshold should be some comperator circuit that turns the whole compression circuitry off as long as the (cv-)signal is below a set amplitude. Than p3 would set the ratio? p4 the attack?
I start to repeat myself, i think you get the confusion i have. Any hints?
Ps.: just found this schematic. He doesn´t lable the controlls, but there are a few more. Ok, R16/17 are timing. Whats R14 doing?
And another thing: Once i´m into this i need to find out how to connect meters for in/out and reduction.
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