interview series (11) – Andreas Eschenwecker

Andy, your Vertigo VSC compressor has already become a modern classic. What has been driven you to create such a device?

I really like VCA compressors. VCA technology gives you a lot of freedom in design and development and the user gets a very flexible tool at the end. I was very unhappy with all VCA compressors on the market around 2000. Those were not very flexible for different applications. These units were working good in one certain setting only. Changing threshold or other parameters was fiddley and so on. But the main point starting the VSC project was the new IC VCA based compressors sounded one dimensional and boxy.

Does this mean your design goal was to have a more transparent sounding device or does the VSC also adds a certain sound but just in a different/better way?

Transparency without sounding clean and artificial. The discrete Vertigo VCAs deliver up to 0,6% THD. Distortion can deliver depth without sounding muddy.

Does this design favour certain harmonics or – the other way around – supresses some unwanted distortions?

The VSC adds a different distortion spectrum depending when increasing input level or adding make-up. The most interesting fact is that most of the distortion and artifacts are created in the release phase of the compressor. The distortion is not created on signal peaks. It’s becoming obvious when the compressor sets back from gainreduction to zero gainreduction. Similar to a reverb swoosh… after the peak that was leveled.

Where does your inspiration comes from for such technical designs?

With my former company I repaired and did measurements on many common classic and sometimes ultra-rare compressors. Some sounded pretty good but were unreliable – some were very intuitive in a studio situation, some not…
At this time I slowly developed an idea what kind of compressor I would like to use in daily use.

From your point of view: To which extend did the compressor design principles changed over the years?

The designs changed a lot. Less discrete parts, less opto compressors (because a lot of essential parts are no longer produced), tube compressors suffer from poor new tube manufacturing and some designers nowadays go more for RMS detection and feed forward topology. With modern components there was no need for a feedback SC arrangement anymore. I think RMS is very common now because of its easy use at the first glance. For most applications I prefer Peak detection.

Having also a VSC software version available: Was it difficult to transfer all that analog experience into the digital domain? What was the challenge?

In my opinion the challenge is to sort out where to focus on. What influence has the input transformer or the output stage? Yes some of course. Indeed most of the work was going into emulating the detection circuit.

Which advantages did you experienced with the digital implementation or do you consider analog to be superior in general?

I am more an analog guy. So I still prefer the hardware. What I like about the digital emulations is that some functions are easy to implement in digital and would cost a fortune in production of the analog unit.

Any plans for the future you might want to share?

At the moment I struggle with component delays. 2021/22 is not the right time for new analog developments. I guess some new digital products come first.

Related Links

TesslaSE mkII released

TesslaSE mkII – All the analog goodness in subtle doses

TesslaSE never meant to be a distortion box but rather focused on bringing all those subtle saturation and widening (side-) effects from the analog right into the digital domain. It sligthly colors the sound, polishes transients and creates depth and dimension in the stereo field. All the analog goodness in subtle doses. It’s a mixing effect intended to be used here and there where the mix demands it. It offers a low CPU profile and (almost) zero latency.

With it’s 2021 remake, TesslaSE mkII sticks to exactly that by just polishing whats already there. The internal gainstaging has been reworked so that everything appears gain compensated to the outside and is dead-easy to operate within a slick, modernized user interface. Also the transformer/tube cicuit modeling got some updates to appear more detailed and vibrant, while all non-linear algorithms got oversampled for additional aliasing supression.

Available for Windows VST in 32 and 64bit as freeware. Download your copy here.

FerricTDS mkII released

FerricTDS mkII – the updated award winning Tape Dynamics Simulator

New in version 2:

  • Introducing operating level calibration for better gainstaging and output volume compensated processing
  • Metering ballistics revised and aligned accordingly
  • Updated tape compression algorithms increasing punch, adding 2nd order harmonic processing, less IMD
  • Updated limiter algorithm featuring ADC style converter clipping
  • All non-linearities are running at higher sampling frequencies internally
  • Adding a sophisticated analog signal path emulation

Available for Windows VST in 32 and 64bit as freeware. Download your copy here.

announcing Thrillseeker VBL – Vintage Broadcast Limiter

Bringing mojo back – Thrillseeker VBL is an emulation of a “vintage broadcast limiter” following the classic Variable-Mu design principles from the early 1950’s. They were used to prevent audio overshoots by managing sudden signals changes. From today’s perspective, and compared to brickwall limiters, they are rather slow and should be seen as more of a gain structure leveler, but they still are shining when it comes to perform gain riding in a very musical fashion – they have warmth and mojo written all over.

Thrillseeker VBL is a “modded” version, which not only has the classic gain reduction controls but also grants detailed access to the amount and appearance of harmonic tube amplifier distortion occurring in the analog tube circuit. Applied in subtle doses, this dials in that analog magic we often miss when working in the digital domain, but you can also overdrive the circuit to have more obvious but still musical sounding harmonic distortion (and according side-effects) for use as a creative effect.

On top, Thrillseeker VBL offers an incredibly authentic audio transformer simulation which not only models the typical low-end harmonic distortion but also all the frequency and load dependent subtleties occurring in a transformer coupled tube circuit, and which add up to that typical mojo we know from the analog classics. This would not have been possible with plain waveshaping techniques but has been realized with my innovative Stateful Saturation approach, making it possible to model circuits having a (short) sort of memory.

Release date is not yet confirmed but most probably will be in May this year.

what I’m currently working on – Vol. 9

Updates and a brand new release, basically. Since there is a minor issue with the latest TesslaPRO and Rescue versions concerning higher sample rate compatibility, I’m currently into bug-fixing and both will probably make it upfront the summer break. As the next major update you all voted FerricTDS to be the object of desire and I’m already sketching things on the drawing board but developments might not start before Q3.

I’m constantly extending and improving my Stateful Saturation approach and the next incarnation will bring authentic analog style distortion into VST land. It is basically a Variable-Mu based broadcast limiter design from the early days but which is modded to have detailed access to the amplifier distortion – it has warmth and mojo written all over! Patrick also joined in again and will perform his magic user interface artwork. An official announcement will appear very soon, so stay tuned.

Unfortunately, there are no news about 64bit support atm.

Related links:

BaxterEQ – update 1.0.1 available

BaxterEQ

BaxterEQ – transparent mastering and mix buss shelving EQ

Changes in version 1.0.1

  • A smaller GUI version is included
  • VST vendor tag is corrected

BaxterEQ is a Windows x32 freeware release for VST compatible applications and you can grab your copy via the download page.

If you like, join me on Facebook! If you wish to donate just click here.

Related

BaxterEQ – released today

BaxterEQ

[Read more…]

BaxterEQ – final teaser and release info

(click to enlarge)

[Read more…]

NastyDLA – final teaser and release info

[Read more…]

NastyDLA – technical architecture

NastyDLA - technical architecture

simplified technical architecture

Internally, NastyDLA consists of quite a bunch of DSP processing building blocks which as a whole are summing up to an authentic signal path simulation of it’s analog models. The blocks and the according signal flow are shown in the diagram above. Basic signal flow goes from left to right except the feedback path which goes in the opposite direction.

With NastyDLA, signal path coloration already starts in the input stage which provides a complete model of both, frequency and phase response as well as dynamic saturation. It’s located in the dry path but all nonlinear processing and coloring can be disabled on demand so it remains as a simple input volume control then. But while switched in, the input stage can greatly contribute on getting the processed signal to fit right into a mix. [Read more…]