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How about we pool knowledge and understand the Compressor block options better...

austinbuddy

Fractal Fanatic
The Fractal Wiki has some good stuff here, mostly off the manual. I'm going to re-post it at end/below.

But first, I'll start...we generally know what compressors do (squash existing dynamic range - sometimes too much!)....add sustain...focus the sound...

...People put them in front of amps (usually pedal compressors) for a few reasons...get the country chicken' picking thing going - where all the picked notes are basically even in volume... or to increase lead or chord sustain....or squash cleans good (like the 80's all over again)...and back in the 70's, Lowell George of Little Feat used two studio-grade compressors (UA 1176s) in series to get that endless slide sustain thing happening into his Dumble...

...In the recording studio, compressors for guitars are usually put after the mic preamp coming off the cab for a few reasons....one is to tame the signal transients when recording -- leveling out the highs and lows...the other is to mildly compress the incoming signal (like 2:1 ratio ) but then turn up the compressor's output UP to slam the the signal going onto the recorded track, to make guitars sound more punchy....

...And of course compressors are usually heavily used on recorded bass guitars (sometimes compressing them two or three times!)....or across stereo buss mixes to punch up the final sound and "glue" all the instruments together (as one example, that Universal Audio SSL stereo buss compressor plug-in is fantastic, I can use it on everything coming out my monitors -- it makes everything sound better and never sounds like a compressor working!)...

So the major types/food groups of compressors are VCA, Optical, FET, and VariMu. One good explanation is here, for the Logic Plug-in emulations. I found this pretty useful detailed Logic Compressor comparison cheat sheet here as well. (Maybe we can make one for the Fractal compressor models?)

From what I can tell, Cliff has not tried to faithfully model specific iconic compressor brands, but instead taken their specs and made them wider, and more versatile. So the original's "DNA" is in there for the food group type, but you make his cool Fractal compressor versions do things the original real ones can't.

So - it would be nice to know, "if we wanted to emulate a (name of iconic compressor here), which Fractal compressor block type should we choose?... For the:

1176? This is an FET FeedBack (not FeedForward) type compressor....(so it can't be the Studio compressor since the Axe-III manual says that the Studio type is a FeedForward...so, is this the new Analog one we can use for an 1176?...)

Fairchild 670? (Tube, or Optical?...)

LA-2A? - (Optical!)

dbx160? It's a VCA...

SSL Stereo Buss? It's a VCA too...

Manley VariMu? Tube type?

Orange Squeezer? (Pedal 1 of course!)

DynaComp? (Pedal 1 again!)

Keeley Compressor? (Pedal 2 perhaps?...)

From Wiki:

Pedal Compressor 1 and 2 – "Pedal 2" uses a different algorithm which is smoother and pumps less than "Pedal 1". CPU usage by both types is much less than the "Studio" type

Dynamics Processor – allows compression or expansion with a single control. When set to negative values, the block compresses the signal. When set to positive values, the block expands the signal

Optical Compressor – based on classic optical tube compressors, famed for their smooth sound. Use it before the Amp block to smooth out your licks and increase sustain, use it after the Amp block for instant “Hit Record” sound

Tube Compressor – based on classic tube compressors like the Altec Lansing 436C. Since this type uses “variable mu” processing it may add subtle, and possibly desirable, distortion to the audio

Analog Compressor – natural soft-knee response, capturing the vibe of the classic compressors of the 70s and 80s

(circa Axe-Fx II) "Optical 1 uses a full-wave rectifier as a detector (peak detector). Optical 2 uses a true RMS detector. The LA-2A and many other compressors use rectifiers as detectors because it's easy and simple. Technically true-RMS detectors are "better" but they are difficult to implement in analog hardware. Whether or not true-RMS is better in actual real-world applications is debatable. There are those that claim that true-RMS detectors more closely replicate the natural compression behavior of the human auditory system. Peak detectors respond more rapidly to transients while RMS detectors have a smoother behavior. The only way to know which you like better is to try them." source

(About the combined optical compressor) @FractalAudio said "It's not an "LA-2A" but it can sound like one. It's a generic optical compressor that can be adjusted to sound like a variety of compressors. It has adjustable attack, release and compression." source" The LA-2A, CL1B, et. al. are high-end studio compressors that use optical circuits." source

So - thought I would get a conversation to further the group knowledge going here! Am NOT a technical expert on this stuff. But I know that the sound of compression is THE sound of rock guitar since the late 60's and we could all benefit from understanding these awesome tools Cliff made for us even better...

So what Fractal compressor types do you use to emulate what famed compressors? (Maybe with luck Cliff will chime in sometime to illuminate further for us)...
 
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2112

Fractal Fanatic
Awesome idea!

IIRC the EL Foil type in the opto comp is modelled after a Distressor which is amazing on bass.

There's also the, Solo
Dallas "Back in Black" tone trick running two comps with the dynamics set to +1 and - 1 to emulate the wireless compander circuit AC/DC used on that album.

A dedicated 1176 style comp would be awesome.
 

fractalz

Experienced
I'm getting a ton of mileage out of the Amp block dynamics section.

I set "Input Dynamics" to -1.5 (more and I find I lose the pick attack) and "Out Compression" somewhere between 4-6. I adjust the "Out Comp Threshold" so that I'm getting 4-6dB of compression.

As mentioned in an earlier thread, the "Feedback" comp type is really interesting too, but the above settings are for the "Output" comp type.
 

Jozsef Kiss

Member
I have an iMac machine.
I'm using Logic Pro X.
Waves Complete, IK Multimedia and other plugins on my machine.
But I still like Logic Compressors.
I didn't know this writing.
But now I will use the Logic compressor more consciously.
Thanks for this tutorial!
Very good review!
 

fractalz

Experienced
The UAD plugin documentation has a ton of info on the classic compressors that they have modeled:

http://media.uaudio.com/support/manuals/v980-ke7SQ3o/UAD Plug-Ins Manual.pdf

When people recommend or reach for compressor X vs. Y, it is typically because there is a difference in functionality that is beneficial (fast attack, program dependent compression, side chain filter, etc.). Knowing which compressor is which is useful.

Then, breaking the rules is fun too. Apple's Logic emulates the sound of a bunch of classic compressors but they all use the same UI. So, you can create a fast-attack LA-2A or a side-chain filtered 1176 - things that don't exist in the real world.

With guitar, a lot of the compression I use impacts the *feel* of playing and I can tune it by how the guitar reacts. For mixing, it's all about hearing what the compression is doing and that is harder. I like the tutorials over at Pure Mix that talk about listening to compression and hearing what it does:

https://www.puremix.net/video/how-to-listen-compression-edition.html

https://www.puremix.net/video/principles-of-mix-bus-processing.html
 

austinbuddy

Fractal Fanatic
The UAD plugin documentation has a ton of info on the classic compressors that they have modeled:
http://media.uaudio.com/support/manuals/v980-ke7SQ3o/UAD Plug-Ins Manual.pdf
Agree - I have all the major food group Universal Audio compressors, and I love that they provide presets.

Right now, one main question I have is: which of the Fractal Axe-Fx III compressors can most closely emulate the UA 1176 compressor?

Followed by, which one can most closely emulate the famed Fairchild 670?

Before we had the new options, I would have reached for studio for 1176 and then Optical for Fairchild. By adding the Tube and Analog options, and then learning that the studio compressor is a "FeedForward" compressor (and 1176 is a FeedBack one), now I'm not really sure a much what to pick for what emulation...
 

austinbuddy

Fractal Fanatic
Another thing I've seen: the great Andy Wood said at Axe-Fest ( I watched live stream) he often runs a compressor first and then really raises the compressor block's output high (not just unity gain to uncompressed sound) to deliberately "slam" the front of the amp (similar to a clean boost drive, but with a compressed signal)....
 
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unix-guy

Legend!
I put a Compressor first in my signal chain... But I don't use the pedal type.

I think this comes from using the Carl Martin compressor pedal for years.

Originally, I used the Studio model, then switched to Optical when they were added. Recently, I switched to Tube model, and I like that one best.

I do you use it mildly just to smooth the transients and bump the level up just a bit to bring the phat.
 

levipeto

Fractal Fanatic
Another thing I've seen: the great Andy Wood said at Axe-Fest ( I watched live stream) he often runs a compressor first and then really raise the compressor block's output high (not just unity gain to uncompressed sound) to deliberately "slam" the front of the amp (similar to a clean boost drive, but with a compressed signal)....
Must be an "Andy" thing, because Andy Timmons does the same thing. How he sets a Mesa Loan star is kind of meh, but when he engages the comp with a high output, the amp comes alive with an amazing tone.
Try that in the AFX3, you will amazed!
 

yyz67

Inspired
There's also the"Back in Black" tone trick running two comps with the dynamics set to +1 and - 1 to emulate the wireless compander circuit AC/DC used on that album.
Playing with this now with them in parallel (around +/-1) tuning by ear. Sounds pretty for cleans, tho haven't tried on crunch or high gain presets yet. I like pick attack as well so setting attack high on both with mix on both at 50%.

Leon, do you have any recommendations for routing and settings?
 
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2112

Fractal Fanatic
Playing with this now with them in parallel (around +/-1) tuning by ear. Sounds pretty for cleans, tho haven't tried on crunch or high gain presets yet. I like pick attack as well so setting attack high on both with mix on both at 50%.

Leon, do you have any recommendations for routing and settings?
This thread lays it out - try them in series with the first dynamics type at -1 (comp) and the second at +1 (expand) to emulate the wireless.

For high gain players the multiband compressor is a godsend

 

austinbuddy

Fractal Fanatic
Compression Confession: in my old pedal rigs, I used to not be a big compression fan or user, I LIKED having all the dynemic range (and the Bogner 101b Ecstasy I played gave me plenty of it!)...

But then one day I tried the old two-knob Keeley Compressor, set pretty low, and it just made everything sound so juicy and good, in a transparent way.

I think I read somewhere that Mr. Keeley said he thought an optimal release time for guitars was something like 300ms...the late great Stephen Bruton of Austin was also a fan of this pedal, and Bruton once told me "I just leave it (the Keeley Compressor) on for everything."
 
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