the magic is where the transient happens

Transients and so on

This article could have been an esoteric one but then it would probably be titled as “the magic is where the change happens” or something like that. Don’t worry, this is just about some findings and myth on audio transient processing and it’s, errm, reincarnation in the upcoming TesslaPRO VST audio plug-in.

When once finished the very first fully functional prototype of TesslaPRO and tested it on a whole mix I had that instant big smile on my face one rather see on some really rare occasions. And this is why.

Beside some other neat stuff TP features a new developed circuit which lets you control the amount of the applied effect related to the signals transient flow. There is a dedicated so called TRANSIENTS dial which determines how long the effect is somehow “delayed” when an audio transient occurs. Turning the knob straight to the left means all transient information gets processed. Turning the knob to 12 a. m. position means 7 miliseconds of the transient remains unprocessed and straight to the right even 30 ms is passing through untouched.


“Save our transients” – Bob Humid

Applying this to a whole mix or stereo submix or so can lead to some unexpected “side effects” beside that obvious effect that some amount of the transient information survives the saturation process:

  • The audio signal appears to be more focused but natural and relaxed at the same time
  • The audio signal appears to have some more stereo width content
  • The audio signal appears to be more “3-D”
  • You will have some big smile on your face

I was really amazed that there is this subtle but nice widening effect when relaxing the very first transient information from the saturation process (there is no M/S processing performed here!) but on the other side this observation is correlating to some physics and perceived effects in analog devices. The simplistic and basic waveshaping theory in the digital domain handles saturation as a static and instantaneous sort of effect while in some analog components such as transformers and tape devices this ain’t true at all.

Those analog devices are truly capable of capture and reproduce significant amounts of audio transients but just are limited energy wise (which briefly means the sum of audio level over some time). This way very short attacks are reproduced faithfully and just slightly polished while when constantly driven hard the well known distortion occurs. And that is a big part of all the magic which is linked that much to highend analog audio gear. Forget all the rumble about noise, crosstalk and all that stuff – the transient is the place where the magic is going to happen (or not).

The TesslaPRO audio processor

The TesslaPRO audio processor

So, after all those theory back to practise and implementation. TesslaPRO will feature some new and exciting approach on signal saturation modeling beside some other way coolย  stuff. One really important note on the implementation is that even though there is some dynamics processing introduced there will be no audible artifacts implied by intermodulation distortion which is a common problem in e.g. compressors. Using TesslaPRO one just will hear the saturation processor if it’s applied over the audio flow but no modulation artifacts by the dynamics!

The saturation which is actually applied is output level compensated and there is a much more accurate and faithfull transformer style bass distortion simulation which was already introduced in BootEQ mkII. The audio input can be boosted +12dB and the core algorithm is four times oversampled to minimze further aliasing artifacts. Apart of the mandatory VU display TesslaPRO renders a second (red) needle into it which gives some visual feedback on how much transient information is actually passed or not.

TesslaPRO is going to be released in May 2009 and will be available as freeware for PC and VST capable hosts.


  1. Bootsy, you’re the man!! Seeing the TesslaPRO GUI (thank you Patrick!) already gives me a smile on my face and reading about the wonderful magic this plugin creates makes me smiling even more! Hearing it in action will make me smile for “more than a while” ๐Ÿ˜‰ Thank you VERY MUCH for another amazing tool! I’m so glad it is soon to be released ๐Ÿ™‚

    • Samuel Onervas says:

      I just tried the Tessla PRO plug on my drum buss and it’s exactly what I’ve been looking for and it’s just amazing! I also tried your Nasty series on some basses and sounds and I’m blown away. The way I could dial in some harmonics for deep sinus basses etc is just the tool I need to make my mixes stand out. Thanks again for making/sharing your amazing work and I wish you all the best for the future. You got some killer plugs here, I’m really impressed and if you need Beta testing in the future I’m up for it.

      (XP SP3, Live 8.04, Duende, Uad cards)


  3. I can’t wait ๐Ÿ˜€
    This sounds awesome.

  4. great !
    and nice looking

  5. this is sounding amazing; does it do something to the space/time continuum too? because that big smile on my face it’s supposed to make, i think it’s already happening!

    compliments to your gui guy too for another beautiful piece of work… hey, is it May yet? darn…

  6. Loving the look of this. Can’t wait to try it out!

  7. Damn, Bootry this is awesome looking, I think I want a pic of this on my desktop, mobile phone, office, car…everywhere! …I will be smiling constantly! ๐Ÿ™‚

    What a beautiful interface. (Well done Patrick)

    Can’t wait to hear what this baby will do, perhaps turn the smile into tears of happiness maybe? ๐Ÿ™‚

    Keep it up mate and may it arrive soon!

  8. Wow – I must admit I have high expectations here!

    Thanks and thanks again for this Bootsie!

    May is here pretty soon


  9. Hey,

    This is WONDERFUL.

    I’m sure you nailed it even more with this PRO version.

    Let’s hear how it sounds as soon as it gets released.

    A note to Patrick : keep up the AWESOME work, and keep working with Bootsy.

    Jay Key

  10. Just a side note about the artwork: This time I talked to Patrick and said, do whatever you want, I just need four knobs and a VU and it should look somehow unique and timeless and to stand on its own. And two weeks later he delivered right that. That man is incredible.
    At the moment I’m trying to persuade him to give some more insight on his work here …

  11. Major Edition says:

    Bootsy is a genius. I’m always wondering what he is up to next. He is very good at what he does. Your work always sounds amazing and put a lot of smile on our faces.

    Patrick, 2 thumbs up for the good work you and Bootsy do together. Keep it up. You are both appreciated.

  12. Hey!
    Thank you guys, thank you Bootsy!
    My pleasure. ๐Ÿ™‚ And for the insight: count me in!

  13. Compared to most other freeware plugins your plugs really look sexy. ๐Ÿ™‚

  14. susiwong says:

    Just wow !

  15. It’s pure evil genius!!! And it’s going to be free?!?

  16. ok ok It’s May already…….drooling here ๐Ÿ™‚

    When can we expect this beauty?

    My pants were jizzed a while back Jim lol ๐Ÿ™‚ ๐Ÿ™‚ ๐Ÿ™‚

  17. sunny_j says:

    i would not be surprised if bootsy released it on may 31, he likes to torture people first ๐Ÿ™‚ ๐Ÿ™‚ ๐Ÿ™‚

  18. ROFLCOPTERS at all three of you guys. ๐Ÿ˜‰ Nice to see you both ha33y and sunny_j. And nice to hear from you as always Bootsy.

  19. Dude…I’m actually looking forward to hearing this thing.

  20. so how close are we Bootsie?

    a day? a week?

  21. Probably towards end of May …

    • cool, at least now i know i gotta try and put myself to sleep for a few weeks so I don’t think about this ๐Ÿ™‚

  22. OMG!! SUNNY_J WAS RIGHT!!! ๐Ÿ˜ฎ END OF MAY!! ๐Ÿ˜†

  23. sunny_j says:

    well not to worry. i know that the final product will be worth it. besides, he likes to test the things for bugs so we don’t have to.

    great work bootsie my man

  24. This look very promising! The BootEqmk2 is my to go eq atm and i have high hopes for the new tessla.

    A simple question, what does tessla pro add to the sound that the booteqmk2 can’t?

    Check out my swedish popband @

  25. The Transient handling is different.

  26. sunny_j says:

    @ The Transient handling is different.

    he means it is better-different ๐Ÿ™‚

  27. abrooklynartist says:

    Yay! Can’t wait.

  28. Can’t hold my breath for much longer Bootsy better speed up the release process cause I may end up in hospital and it will be your fault ๐Ÿ™‚ ๐Ÿ™‚ ๐Ÿ™‚

  29. kingocounty says:

    I can hardly wait for this myself. I LOVE the BooteqMkII and am looking forward to yet another great tool to use. It’s amazing that this stuff is free and I thank you yet again for being so generous with your work.

  30. gurujon says:

    WOW! If this sounds as good as it looks, I would give a nice donation for this one. I love your plugs, they are amazing!
    Thank you very much!

  31. I’m a big fan of Bootsy’s earlier plugins. In particular I’m using Tessla a lot on drum submixes as it is an excellent saturation plugin.

    Reading through the above article about TesslaPro I think I’ll be able to do even more magic to drum- and percussion-mixes than before!

    SOunds like a must have plugin for me!


  32. sunny_j says:

    Bootsie, my man. i know u are a perfectionist and all but i think its about time u released the monster. can’t wait any longer

  33. we are all getting withdrawal symptoms

    I have high blood pressure and heart palpitations and all because I am waiting for this beauty to land on my system.

    ๐Ÿ™‚ ๐Ÿ™‚ ๐Ÿ™‚ ๐Ÿ™‚ ๐Ÿ™‚

  34. sunny_j says:

    c’mon lucky friday

  35. Patience my young jedi, I’m just finfishing the manual during the next days …

  36. Jacarรฉ says:

    Hey Bootsy !
    Just want to drop here my big thanks to you for all those amazing mixing/ mastering/ creative tools you are giving to us for free. The latest BootEQ MKII is just amazing… sweet. And Rescue… can’t even describe what it does to my mixes (in a very good way). Tessla Pro promises very much and I’m sure it will deliver it.

  37. So, today is lucky Friday, and no TesslaPRO. So what’s it today Bootsy, TesslaPRO, or tease? ๐Ÿ˜†

  38. sunny_j says:

    well then c’mon lucky sunday ๐Ÿ˜€

    but u can’t hurry these things u know ๐Ÿ™‚

  39. must be a big manual ๐Ÿ™‚

  40. dasdeck says:

    what does the”G” stand for?

  41. yuhuuuu

    bootsy rules ! thank you for your amazing work, your stuffs sounds ANGRY

    ๐Ÿ™‚ best regards

  42. Very cool plugin, was using alot last. I did encounter a crash with Sonar 8, is there any way to submit a bug report?. Other than The plugin seems pretty Solid nicely designed. I love it.

  43. Mads Lj says:

    Actually this is a much more subtle effect than I imagined, but maybe it’s the material I have tested it on. But subtle is often what’s needed if it’s the “right kind”.

    One thing that could be considered was m-s of the different controls, in some future update, for added flexibility, or maybe as a separate stereo enhancer of a different sort.

    Under all circumstances thanks for your great work I will look forward to try the new Tessla on a lot of different audio-material…

    Let’s hope some more comments show up as time go along, and best wishes for all your projects Bootsy

  44. Jacarรฉ says:

    I’m justv amazed by this plugin ! Very subtle, and sweet. Again, a work of genius (no, there’s not enough asskissing for bootsy).

  45. Another jewel…TesslaPro. Too Sweet.

  46. Thank you for this unique tool! Your work is really creative and this plugin rocks!

  47. Justin Roche says:

    Hello everyone at Variety of Sound.
    I like your website and see that you all have been very generous in offering the produce of your labors in plug in design / programming.
    However, just one comment that I would like to make, or perhaps even a request.
    Do you think that it would be wise to include a page for each plug in describing each plug ins design and its uses, as on the download page, it is pretty unclear.
    Your plug ins are also not on the KVR database either, so it is a little ambigious as to what each plug in does and in some cases, what they look like?!!
    This I feel is a shame, as the plug ins that I have seen look like they have been designed very well.
    Don’t let your self down by lack of marketing / info!
    Anyway, good luck what ever your objectives may be.
    Justin Roche
    BA in Sound Technology

  48. I have to admit that for me Bob Humid is one of the most arrogant, pseudo-cool blurb-fragile egos ever, who can’t write a single comment or review without letting all know how supa-kewl he is, and how he disregards all who are now disregarded by the mainstream – but as Tessla Pro is such an outstanding plugin that indeed gets a smile on my face whenever I use it :), you might quote dozens of people like him, as long as they don’t make your plugins sound nasal and fragile/sharp!! Lovely work, just like your epic verb. Simply outstanding.

    And indeed KVR is full of well justified praise for Bootsy – in fact the plugins are not hard to find at all. I think everyone who loves music and uses vst plugins will anyways have this great website bookmarked^^. Thanks, bootsy, really happy with your plugins!

  49. This is amazing plugin, but doesn’t work correctly at sample rates higher that 44.1K. Effect seems to multiply with sampling rate and at 4x it just pans both channels to +- 90 degrees and removes everything in the middle, including bass.

  50. Mc Alves Portugal says:



  1. […] Mehr Infos zum TesslaPRO findet Ihr auf Bootsys Seite:ย […]

  2. […] more information on TesslaPRO see here and to download click through the Downloads tab in the navigation […]

  3. […] discusses the creation of TesslaPro and the ideas behind it here. It’s a very useful […]

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  5. […] regarded classic chorus echo device with tape-delay simulation and the critically acclaimed “transient aware” signal […]

  6. […] Just read what the developer himself writes about his tool: LINK […]

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