Fred Forsell's Opto Sidechain become a full opto compressor one day!

It all started with a [discussion] at ["the Lab"] about a small and fine design by [Mr Fred Forsell] for a [opto compressor sidechain]

The idea evolved...

So far we have:


Side chain

Mr. Forsell contributed a PCB Layout ...

[PDF] (external link)

..., the gerber files: [ZIP] (external link) and

... and a complete schematic
[PDF] (external link)

M. Nats contributed another PCB layout:

[PDF] (13kB)

[PDF] (17kB)


Amp stage

Buttachunk contributed a makeup amp stage stage:
New version (will sound cleaner):

Buttachunk's old version (will sound darker):



Schematic for a LED bar based metering:

[PDF] (external link)

PCB Design by M. Nats:

[PDF] (9kB)

[PDF] (12kB)



The compressors slopes/characteristics:

[PDF] (external link)


Expect more to come

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