Flatline compressor

Started by PBE6, January 31, 2016, 03:36:11 PM

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snk

#20
Hello
Further comments about my build :

1- Is there any component/value to change to get a HPF sidechain in the compressor path ?
I mean, i would like to remove the bass (say around 100-150Hz) from the compressor circuit, without removing them from the "audible sound", so the low frequency will not trigger the compressor as much. I am thinking about a switch with the stock value (which is great) on one side, and a "HPF sidechain" on the other side of the switch... but i don't know chich component value i shoud lchange to reach this effect  :icon_confused:

2- As written above, I have added an indicator led by plugging it into A3 and C3 (from the verobarod linked above). It gives a rough estimation of the compression occuring, so it's good, but i noticed that it also some very nasty crackles as soon as i don't have the sutain setup to the maximum position. So, i removed it  :'(
So, is there any way to keep an indicator led, but not having it modfying the processed sound ?

3- Also, given that i used 25V capacitors, can it run @ 18V or should i better stick to 9V?

rankot

You can probably make two separate opamp -> rectifier chains, one for indicator and one for LDR. They can be preceded with signal splitter, so you can split signal for compressed output from signal that can be HP filtered and used for compression/indication.
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snk

Quote from: rankot on October 20, 2018, 05:06:16 AM
You can probably make two separate opamp -> rectifier chains, one for indicator and one for LDR. They can be preceded with signal splitter, so you can split signal for compressed output from signal that can be HP filtered and used for compression/indication.
Thank you Rankot  ;)
Unfortunately, i am not skilled enough to know how to do such a thing  ;D
Is there any circuit/schematic/layout somewhere to get a hint about the right way to do it ?

May I try following the same guidelines from the LightSpeed compressor, or wouldn't it work at all ?
https://www.diystompboxes.com/smfforum/index.php?topic=113668.0


rankot

C6 is a HP filter in this Lightspeed Comp. So you can add a SPST switch in parallel with C6 to turn HP filter on or off. Or you can make it like this:



Use On-Off-On switch, so you can have three values for HPF:
- HPF off (C6 shorted)
- HPF higher frequency (switch in a middle)
- HPF lower frequency (switch to C6A)

You can try different values for C6/C6A.
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snk

Ok, thank you.
So, for the Flatline, would it be this 100k resistor (going to pin5 of the opamp) ?

rankot

You shall put this switch/cap combo between pin 1 of the IC and row of you layout, instead of that single wire.
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snk

Quote from: rankot on October 20, 2018, 06:08:44 AM
You shall put this switch/cap combo between pin 1 of the IC and row of your layout, instead of that single wire.

Hi, sorry, english is not my native laguage, and i am not very skilled yet when it comes to electronics, so i am not sure i am understanding  :icon_redface:
Which "row of your layout" and "single wire" are you talking about ?
So the 100k resistor outlined in white is not the right one, that's correct ?
"pin1 of the IC" is on D (line) 6 (row), right ?



rankot

Look at the black wire marked with a white X.

100k resistor is not of concern.


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snk

AH, perfect, it makes sense : thank you, Rankot !