Compression Topology With Andrew Scheps

Pro Video

01h 34min


Have you been wondering about the differences between the types of compressors in your plugin folders? FET, VCA, MU, Optical... these are the types we see, and all have very different characteristics.

In this exclusive, Andrew Scheps dives into the topology of compressors and explains the uniquities in how each operates and the overall effect on their sonic signature.

See how Andrew Scheps:

  • Explains the main controls of compressors
  • Explains how compressors work once the threshold is exceeded
  • Discusses how feed forward and feed back compressors work
  • Dissects the difference between the 4 types of compressors
  • Explains how each of the compressors has unique quirks in their operation
  • Explains what happens in "all buttons in" mode on an 1176
  • Runs through each of the compressors on pianos, vocals, drums, and full mixes and gives a detailed explanation of what he is hearing
  • Demonstrates how you can alter the behavior of a compressor with sidechain EQ

Check out the iZotope Blog Article mentioned in the video here

Join Andrew Scheps and learn the operational and sonic subtleties of each type of compressor. Only on

Equipment & Software
  • Scheps Omni Channel
  • Softube Tube-Teck CL 1B
  • Solid State Logic SSLG Channel
  • UAD Teletronix LA-2A
  • Waves API-2500
  • Waves CLA-76
  • Waves PuigChild 670
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    Andrew Scheps

    Andrew Scheps is a music producer, mixing engineer and record label owner based in the United Kingdom. He has received Grammy Awards for Best Rock Album for his work on Red Hot Chili Peppers' Stadium Arcadium, Album Of The Year for Adele's 21, and also Best Reggae Album for Ziggy Marley's Fly Rasta.

    Andrew started as a musician, but found that what he enjoyed most was working behind the scenes. This led him to study recording at the University of Miami. After graduating, he spent some time working for Synclavier, and then on the road with Stevie Wonder (as a keyboard tech) and Michael Jackson (mixing live sound). But he found his home in the studio, and he honed his craft working for producers such as Rob Cavallo, Don Was and Rick Rubin.

    Andrew collaborated with Waves in order to create his own line of plug-ins which include the Scheps 73 EQ and the Scheps Parallel Particles.

    Andrew is one of the best known mixing engineers in the world, well-known for his Rear Bus mixing techniques that he developed working on his 64 input Neve 8068 console and his love for distortion of any kind. If you are watching pureMix videos you will see that he managed to carry his analog sound signature over to a fully portable digital rig. These days, Andrew mixes completely In The Box as it allows him much greater flexibility and the ability to work on several project simultaneously.



    Lana Del Rey

    Red Hot Chili Peppers


    Michael Jackson

    Green Day

    What do you have to say?
    Leave a comment
    2022 Dec 08
    "...the master of the masters of compression, and that's what everybody wants to be" Awesome test with one of the most pedagogical top engineers in the world. Thanks so much Andrew!
    2022 Nov 25
    Andrew, shouldn't this vid's title be "Audio engineer reacts to an article from izotope"? Don't get me wrong, I like your comments but my man...
    2022 Nov 21
    first video after subscribing - wow! definitely gonna try setting the threshold/input higher during quieter parts - kind of like another level of automation to maximize the compression.
    2022 Nov 19
    sou do brazil e sinto falta das legendas nos videos para que nos assinantes brasileiros possa usufluir melhor de todo conteudo. obrigado
    2022 Nov 12
    andrew Scheps como siempre, rompiendola !!
    2022 Nov 09
    For those correcting me on Attack times, you are correct, it is how long it takes to get to the ratio you've set, not to start compressing. I obviously mis-spoke and didn't catch it in the edit. Thanks for pointing that out!
    2022 Nov 09
    You guys are great no doubt, but I’m super disappointed that there’s no mention of diode bridge compressors. I believe they’re a type of FET. Guess I’ll have to do more research on my own. Thanks PureMix. Great content as always.
    2022 Nov 09
    A compressor deep dive by type from a dude who knows way too much about them!! I'm stoked, best news all day!
    2022 Oct 30
    Is it possible by subtitles (french, spanish or portuguese) please? Thanks ; )
    Jimi Lloyd-Wyatt
    2022 Oct 20
    Cool video, however my understanding was that Attack times aren't "how long before the compressor starts working" but rather 'how long it takes for the full ratio to be imparted onto the signal once the threshold has been met'. What this means is that the compressor will start compressing as soon as the threshold has been met, but it will impart all of its 4dBs or 10dBs of compression over the duration of "X" milliseconds. It doesn't mean that the compressor "waits around" for 15ms before it does something, that would require a really complex delay unit in the pre digital days.
    Mr Rambolini
    2022 Oct 07
    So educational - Truly grateful. Thank you Andrew and Puremix!
    Trevor Nokes
    2022 Oct 03
    Superbly educational for the ears. Excellent as usual from Andrew.
    2022 Sep 13
    You are the best teacher Andrew!! thanks for all these content!!
    2022 Sep 12
    @f.otto. Tmboy. Focus (great group, great songs) and I always learn something valuable from Andrew and Puremix in general. What I need is a release knob for my memory to retain things a bit longer.
    2022 Sep 11
    Hello! What's the song during the mix bus compression at the 41 minute mark?. Merci.
    Martin Guldberg
    2022 Sep 10
    The Tubetech CL-1B actually has pretty fast attack times if you need it: "For example the LA-2A OPTO compressor has program dependent attack times starting at 10 milliseconds. However, other OPTO compressors are faster like for instance the Tubetech CL-1B which lists attack times as fast as 0.5 milliseconds (the attack is fully adjustable up to 300 milliseconds) wheras the release time can be adjusted freely between 50 milliseconds and 10 seconds. This makes the Tubetech CL-1B a very versatile and flexible compressor." Taken from:
    2022 Sep 10
    I missed Diode Bridge in this one. For some reason it always flies under the radar, although it’s such an interesting topology that ranges from almost VCA-clean to complete mayhem, very punchy and very gooey.
    2022 Sep 10
    A detail with Attack and Release times... Gregory Scott from Kush Audio, designer of audio gear and plugins, explained these better in an article some years ago : Attack and Release have not much to do with threshold, as he said : "Any time the gain reduction meter is increasing (i.e., the comp is reducing the gain of the signal), the compressor is attacking. Any time the gain reduction meter is decreasing (i.e., the comp is restoring the gain of the signal), the compressor is releasing."
    2022 Sep 10
    For the 1176, it's important to know that Attack and Release values get faster as you turn the knob to the right. Scheps doesn't actually go into this explicitly in the video. I'm sure this is second nature to him, but it can be confusing for someone encountering an 1176 plugin for the first time. Most other compressors have faster values on the left and slower values on the right. Effectively you can think of the 1176 knob representing "attack speed" (gets faster as values increase) vs "attack time" (takes more time as values increase).
    Alexandre Si
    2022 Sep 10
    Woooow !!! Thanks Andrew ! Amazing as always
    2022 Sep 10
    I find this video not well thought out: not enough clear A/B comparison to really hear differences, more Andrew's stream of consciousness. Some good nuggets of wisdom in there, but not worth spending 1.5 hors to watch for me.
    2022 Sep 09
    I'm so glad he did this because I'm way to lazy to do it myself! but it really showed the differences in, pretty much, all my favorite comps! Thanks Andrew! Now time to go check outs fab's comp vid.
    Brian Bolger
    2022 Sep 09
    Finally a clear explanation of the whole feedforward/feedback thing!
    2022 Sep 09
    That was very interesting, Have to listen again to make sure I get it. Excellent tutorial, well explained and thanks.
    2022 Sep 09
    If you're going to do a paid video on different plugins, please don't say you "assume" anything... read the manual and do an accurate presentation. If you're going to show a CL1B, I would expect you to know what the Fix/Manual option does. If you're not going to bother doing the research yourself, please don't charge for the video. It feels incredibly dishonest. Very disappointed about this approach. I could just as well go check out a free YouTube video.