In the PC4K Bus Compressor, when the threshold is set lightly (just compressing peaks)...

• The VU meter shows the MOST gain reduction when the Ratio is set to 2.
• The compression DECREASES when I set the Ratio to 4, and decreases even further when selecting 10.

When I slam the threshold (compress everything coming in), it reverses, and 10 becomes the heaviest compression.
 
This seems like bizarre behavior. Can anybody verify and/or explain?

See this post by Cakewalk's Bob Currie, explaining the operation of the PC4K:
 
http://forum.cakewalk.com/FindPost/2405895

Thanks. I read the post, but I did not see how it relates to what I'm seeing with the ratio??

Probably the knee gets steeper and shifts upwards or downwards depending on the rate of compression?

Sorry. I thought that it was addressed in that post. There are some other posts in the the thread about ratio weirdness, including at least one of my own. IIRC, the bottom line was that it was Working as Designed but does not work as intuitively as something like the Sonitus compessor because it's modeled after hardware.

Sanderxpander
Probably the knee gets steeper and shifts upwards or downwards depending on the rate of compression?

That's correct and true of other SSL style compressors. The higher the ratio, the more gentle the knee, hence less compression at equal thresholds. I made the same mistake with The Glue until Andy (the developer) explained.

Thank you brundlefly. I had only read Bob's post, but I see you mentioned the Ratio issue too.
 
And thank you Funkybot.  But isn't it the opposite?  Lower ratio = softer knee?
 
If so, I think I understand what is happening:

• A signal at a gentle threshold will peak in the knee of the 2:1 ratio, and get lightly compressed.
  However, at 10:1 it will be mostly uncompressed, as it will barely reach the harder knee (2:1 = more gain reduction in this case).
• Then, when the threshold is clamped down past the soft knee, the full ratio kicks in for both 2:1 and 10:1 (10:1 = more gain reduction here).