Basic Pro Channel Question - I'll RTFM Thanks

This would be the gain prior to compression.

Say you have a 4 db signal coming in....

Your threshold is set at 6...

The comp aint going to do anything cause it hasnt hit the threshold...

To make it work, either you lower the threshold  to a value below 6 or

Raise the input gain. 

The output would be the make up gain, say you knock the peaks off and lower it by an average of 3 db, and you want to bring the overall level backup a bit, you can use the output to do this without affecting how the comp is hit on the input threshold.

Sorry I was talking about the 76. I see the threshold settings on the 4K. Still curious about the input maybe I'll search further on the web.

Or in the manual. I just discovered it's pretty complete. I'll do some reading - nothing to see here.

HumbleNoise


Does the Pro Channel have a set threshold? (or am I missing this setting in PC?) Or does raising the input gain simply create more signal to compress?

Hey Larry - I had similar questions. This is the way I see it now. Remember the Sonitus compressor graph? There was a diagonal line going from bottom left to top right (with a slope of 1), with the top right bit tending to have a flatter slope. When playing a signal through it, you can see the input signal moving up and down the line. If it reaches the flatter part of the line, it gets compressed. That is, the output is made quieter than the input. If the input signal is recorded at a low level, then it never reaches the flatter bit and never gets compressed. To compress this quiet signal, you have to lower the threshold, which drops the flatter part of the line down to meet the quiet signal. The alternative is to make the input signal louder and leave the threshold fixed. This is what the input knob in ProCh does. It's the difference between moving the line down to meet the signal or moving the signal up to meet the line. The only difference is the level of the output signal afterwards, which gets made up with the output knob in ProCh or the gain in Sonitus.

Where the ProCh compressor seems to be different to the Sonitus is that it is less flexible. You can set the slope of the top part of the line to just a few values (4, 8, 12, 20, inf), whereas the Sonitus can set the ratio to anything at all. Also, the Sonitus can change the shape of the knee (where the two slopes meet). ProCh must have this hard-wired.

I must say that I really like the Sonitus compressor, mainly for the graphical display, although I will get used to the ProCh display (which I think shows the amount of compression). However, the ProCh is very convenient.

Cheers, Peter.

If it helps, the ProChannel "76" compressor is modeled after this:


Hi - PLEASE forgive my edit of this post - the link you provided gets redirected to some careers everywhere page instead, and someone else had reported their virus software stopped it, as well.  Soooo, I edited this post only to remove the link in question.
 
(Edited by Bob Bone - only to help folks not accidentally go to a redirected link).

Other links that were kind of interesting:
http://www.nrgrecording.de/urei_1176.html

http://www.nrgrecording.de/html/operation.html


"...
 In order to set the limiter to provide a specific amount of compression, first adjust the Input and Output controls to a fully counterclockwise (CCW) position. Adjust the Attack control a few degree clockwise (CW) so that Gain Reduction is enabled..... Rotate the Input Level control CW until the desired amount of gain reduction is achieved.

Good thread.  I've had the same questions about the Pro Channel Compressor.  My mind is wrapped around the conventional "threshold" concept, which took me a while to understand years ago.  The Sonitus graphics makes compressors very easy to understand.  I love the Sonitus, and I'm grabbing them a lot these days instead of the pro channel because I can see exactly what is going on.  I should be using the pro channel compressor but I don't quite understand it yet.  I wish it had the graphics that the Sonitus has. 

It's cool to have the interface look like a piece of vintage equipment.  But it doesn't help the learning curve for those of us who haven't used the vintage equipment ourselves.

The Sonnitus is designed to work like the Oxford.

The Oxford was designed by the guy that designed the real life SSL.

So, the Sonnitus, bless it's heart, is a darn good copy of one of the most sophisticated, flexible, useful, and good sounding compressor made to date.

When one looks that '76 tradition they are looking at 1965 technology with an extreme limit to the features set and all the sonic consequences that come with that.

When you drive the input of a real 1176 you add character immediately to the tone because the FETs have their own sound in that circuit. You can't get much compression on a single track out of a 1176 without altering it's character.

The 1176 was of course designed and marketed as peak limiter for industrial use and intended to be placed upon a play back system where the music was already hot... the hot mono or two track playback didn't require much boost at the 1176s inputs and so the character at the stage rarely figured into the results because the input stage was just passing the already maxed signal.

When 1176s became commonly used on tracks the intention was to make use of the aggressive and up front sound character that comes from both the input and makeup stages in an 1176.

IMO, the lack of full features on the Pro Channel seems like a step backwards in time.

best regards,
mike