The TesslaSE Remake

There were so many requests to revive the old and rusty TesslaSE which I’ve once moved already into the legacy folder. In this article I’m going to talk a little bit about the history of the plugin and its upcoming remake.

The original TesslaSE audio plugin was one of my first DSP designs aiming at a convincing analog signal path emulation and it was created already 15 years ago! In its release info it stated to “model pleasant sounding ‘electric effects’ coming from transformer coupled tube circuits in a digital controlled fashion” which basically refers to adding harmonic content and some subtle saturation as well as spatial effects to the incoming audio. In contrast to static waveshaping approaches quite common to that time, those effects were already inherently frequency dependent and managed within a mid/side matrix underneath.

(Later on, this approach emerged into a true stateful saturation framework capable of modeling not only memoryless circuits and the TesslaPro version took advantage of audio transient management as well.)

This design was also utilized to supress unwanted aliasing artifacts since flawless oversampling was still computational expensive to that time. And offering zero latency on top, TesslaSE always had a clear focus on being applied over the entire mixing stage, providing all those analog signal path subtleties here and there. All later revisions also sticked to the very same concept.

With the 2021 remake, TesslaSE mkII won’t change that as well but 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 now to appear more detailed and vibrant, while all non-linear algorithms got oversampled for additional aliasing supression.

On my very own, I really enjoy the elegant sound of the update now!

TesslaSE mkII will be released by end of November for PC/VST under a freeware license.

What I like about the Behringer 2600

What I really like about the Behringer 2600 is that it’s not just a plain copy but introduces some real useful improvements over the original concept. Most important to me is the 19″ form factor which not only reduces the originals size and fits in the rack but also remains big enough to enjoy a great user experience while cabling and tweaking things. And they got rid of those speakers! Instead it offers 2 filter revisions to choose from, two of the oscillator sections are now fully featured, the LFO is part of the main chassis now and new additional timing options for the envelopes has been added as well.

On the other hand, the Behringer 2600 sticks to CV gate voltages following original levels which limits full integration in todays modular world quite a bit. However, this is currently not a big deal to me. I only wish they would have made a true analog delay instead of the spring reverb (emulation). Offering audio in, the device also doubles as an excellent analog effect unit which seems to be a little bit underrated in this regard. Given it’s pricepoint, this feature is already something to consider if one is just looking for an outboard analog filter box or an alternative for something like a MS-20.

The ARP 2600 turns 50

And if time allows, watch this awesome documentary about the history and story behind ARP:

What loudspeakers and audio transformers do have in common

Or: WTF is “group delay”?

Imagine a group of people visiting an exhibition having a guided tour. One might expect that the group reaches the exhibitions exit as a whole but in reality there might be a part of that group just lagging behind a little bit actually (e.g. just taking their time).

Speaking in terms of frequency response within audio systems now, this sort of delay is refered to as “group delay”, measured in seconds. And if parts of the frequency range do not reach a listeners ear within the very same time this group delay is being refered to as not being constant anymore.

A flat frequency response does not tell anything about this phenomena and group delay must always be measured separately. Just for reference, delays above 1-4ms (depending on the actual frequency) can actually be perceived by human hearing.

This always turned out to be a real issue in loudspeaker design in general because certain audio events can not perceived as a single event in time anymore but are spread across a certain window of time. The root cause for this anomaly typically lies in electrical components like frequency splitters, amplifiers or filter circuits in general but also physical loudspeaker construction patterns like bass reflex ports or transmission line designs.

Especially the latter ones actually do change the group delay for the lower frequency department very prominently which can be seen as a design flaw but on the other hand lots of hifi enthusiast actually do like this low end behaviour which is able to deliver a very round and full bass experience even within a quite small speaker design. In such cases, one can measure more than 20ms group delay within the frequency content below 100Hz and I’ve seen plots from real designs featuring 70ms at 40Hz which is huge.

Such speaker designs should be avoided in mixing or mastering situation where precision and accuracy is required. It’s also one of the reasons why we can still find single driver speaker designs as primary or additional monitoring options in the studios around the world. They have a constant group delay by design and do not mess around with some frequency parts while just leaving some others intact.

As mentioned before, also several analog circuit designs are able to distort the constant group delay and we can see very typical low end group delay shifts within audio transformer coupled circuit designs. Interestingly, even mastering engineers are utilizing such devices – whether to be found in a compressor, EQ or tape machine – in their analog mastering chain.

64bit plugin rollout started, announcing mkII plugin versions

The very first 64bit plugin versions are out now, starting with the plugins from the public beta test earlier this summer: epicVerb, BaxterEQ, preFIX, NastyDLAmkII, NastyVCS and DensityMkIII. All versions have been carefully revised, are backwards compatible and some includes bugfixes and improvements as well. VST3 versions are not (yet) included due to stability issues. For further release notes and downloads please refer to the download page.

The remaining VoS plugins are planned to be (re-) released one-by-one until end of this year. Most likely, they will reappear as mkII versions 🙂 First one will be FerricTDS mkII which is already in the finishing process and to be released early September.

stay tuned!

42 Audio Illusions & Phenomena

In a comprehensive series of five YouTube videos, Casey Connor provided an awesome overview and demonstration of 42 (!) different psychoacoustic effects. Watching and hearing (headphones required) not only is so much entertaining and educational but also provides some deep insights why we all do not hear in the exact same way. Relevant for all of us in the audio domain whether it is sound design, mixing, mastering or development. Highly recommended!

A more realistic look at the Pultec style equalizer designs

One of the few historic audio devices with almost mystical status is the Pultec EQP-1A EQ and a lot of replicas has been made available across the decades. Whether being replicated in soft- or hardware, what can we expect from a more realistic point of view? Lets have a closer look.

Some fancy curves from the original EQP-1A manual
  • In the top most frequency range a shelving filter with 3 pre selected frequencies is offered but just for attenuation. Much more common and usable for todays mixing and mastering duties would be an air band shelving boost option here.
  • Also in the HF department there is just one single peak filter but this time just for boosting. It offers 7 pre selected frequencies between 3 and 16kHz and only here the bandwidth can be adjusted. However, the actual curves could have been steeper for todays mixing duties.
  • There is no option in the mid or low-mid range at all and also no high pass option. Instead, there is a shelving filter for the low-end which allows for boost and/or attenuation around four pre selected frequencies between 20 and 100 Hz.

All in all, this appears to be a rather quirky EQ concept with quite some limitations. On top of that, the low frequency behaviour of the boost and cut filters is rather unpredictable if both filters are engaged simultaneously which is exactly the reason why the original manual basically states “Do not attempt to do this!”.

Nowadays being refered to as the “Pultec Bass Trick” the idea is that you not only boost in some low end area but also create some sort of frequency dip sligthly above to avoid too much of a boost and muddiness in total. In practise, this appears to be rather unpredictable. Dial in a boost at 3 and an attenuation at 5, just as an example: Does this already feature a frequency dip? And if so at which frequency exactly? One has no idea and it even gets worse.

Due to aged electronics or component variety one has to expect that the actual curve behaviour might differ and also to see each vendors replica implementation to be different from another. In practise this indeed holds true and we can see the actual bass frequency dip at a much higher frequency within one model compared to another, just as an example.

… the more I boost the EQ the more it makes me smile …

A reviewers statement misguided by simple loudness increase?

Fun fact: Like the original device, all current (hardware) replica models do not have an output gain control. Also they increase the overall signal level just by getting inserted into the signal path.

So, where is the beef? Its definately not in the curves or the overall concept for sure. Maybe I’ll take some time for a follow-up article and a closer look into the buffer amplifier design to see if all the hype is justified.

Further Links

Not really demystifying but fun to read:

In the VoS plugin line you can find some Pultec style low end performance within NastyVCS: https://varietyofsound.wordpress.com/2010/05/07/nastyvcs-released-today/

Also interesting to read and hear: https://www.sweetwater.com/insync/pultec-shootout-with-sound-samples/

sustaining trends in audio land, 2021 edition

Now, after spending some time on digging a little bit more deeper into the current offerings and market situation in audio production I just wanted to briefly outline some of my personal summaries regarding sustaining trends but maybe outline also some new things I do see on the horizon.

The mobile audio evolution

To me this indeed looks like an ongoing trend for years now which simply does not stop. On the one hand we can see the whole software and especially the App market continuing and increasing in all areas and platforms: notebooks, tablets, smartphones and their respective eco systems accordingly. Where Ableton once started in providing an almost complete mobile music production approach in literally just a bag, Bitwig and others followed and now Apps are everywhere allowing any kind of recording and music or media production on the go. Apples recent move with the M1 SOC (System on Chip) approach fits perfectly into this trend by increasing the mobility even further in terms of power, size and efficiency. Others will follow this path for sure. Also we can see traditional music gear manufacturers going more and more into compact and battery powered solutions as well, such as the Korg Volca series or the Roland boutique thingies, just to name the two.

The retro cult continues

Companies like Behringer will continue to spit out analog HW clones like there is no tomorrow. Whether thats synthesizer reissues or blatant plain copies of vintage mixing outboard or modeled software – you’ll find everything and in almost all shades of quality and price. And I think this is a really good thing to have such a variety to choose from and also this will lead to some serious price drops in the overpriced used gear market in that area.

Modular madness

I don’t think this is part of the overall retro trend but a niche on its very own. In any case the modular synthesis thing is still gaining more and more momentum. There is a sheer amount of hardware options to choose from and meanwhile also quite a lot of audio interfaces and controller solutions are offering not only Midi but also CV support. Even in software land one can put his/her virtual hands on something modular. All in all, this looks and sounds like real fun and a great opportunity to spend a lot of time on (and money).

Look mom no computer

All those neat outboard DAW-less setups shown on YT: Some hardware samplers and grooveboxes here, some fancy retro synths there and fx stomp boxes all over the place. Well, “Look mom no computer” is of course absolutely wrong here because half of that stuff has tiny little digital displays and computers underneath you have to tinker with. Personally, I would prefer some neat “one knob, one job” analog interfaces plus a real full-blown DAW any day. However, definately a sustaining trend and a good thing.

Loudness war, quo vadis?

While it seems that LUFS finally made it and in fact has been successfully settled as a standard in the broadcast domain – in music production in general it has not. Todays audio mastering target levels are still insane and even some “engineers” continue to present converter clipping as the holy loudness grail to their YT followers. That really hurts. At least some of the big streaming sevices restricted target loudness levels to -14 or -16LUFS which gives a little hope.

ITB production finally took over

Now that even the last renowned mixing engineer has finally surrendered to the dark side in the box – at least for the recording and mixing part – the question remains, why this has taken so long. Was it for quality concerns? The time-to-market pressure to finally have total recall in all regards? Simple ignorance or fear? We might not be sure about the final answer but we do know that today almost everybody can run some media production tasks in a decent quality on his very own while having a low entrance barrier. And this is what I really would call the “game changer” of the last decade. Now, your skills are the limit.

Game of DAWs

There is really no trend in particular here other than the fact that we have the very same players on the board since a decade ago. Maybe Bitwig will aim for the crown from Ableton? It’s whole inherent synthesis and modulation integration make this comprehensive sequencer an instrunment on its very own and also it runs natively on Linux. All the other contenders improved step by step here and there but quite comparable. Maybe having build in mixing scenes and more convincing analog style summing is a thing which sticks a little bit out. So, on my own I wasn’t that much impressed about this very last episodes and now I’m looking forward to an upcoming but much more entertaining season, hopefully.

The pandemic impact

As we all know, the Covid impact on everything live performance related was and still is a sheer desaster. How this will evolve in the future is hard to predict but it is clear that there won’t be any back to normal any time soon if ever. That means this area must transform into the digital/virtual domain as well and most of the suppliers in exact this kind of areas are already the winners of the current situation.

Stay healthy!

 

Rebuilding my Studio

Everything is finished, it just has to be done
– Andreas Pflüger

So, since some 5 years or so I did not had the time and room to make any music at all but at the end I’ve missed it so much that I finally decided to restart all over again and finally rebuild my studio. During my very last attempts in creating music I got stuck somehow inbetween all those endless digital options and just looping stuff in Ableton on my laptop but never managed to get things finished anymore – some of you might know this kind of desease? Anyhow, I decided to setup a small studio production environment like I once had before those laptop times and where I was a little bit more productive, if memory serves me right.

Not a huge setup at all but a small desktop centric approach at home with some few but well selected outboard gear which not only inspires but also invites to perform, record and collaborate whole tracks in a fun way. Luckily, some outboard gear was carefully archived here in my basement but others I do not have anymore, e.g. a real mixing desk. But hey, there is so much cool stuff out there today to consider and to choose from!

Such new setup raises a lot of questions of course concerning workflow and where to better rely on ITB or OTB plus the usual digital versus analog considerations. This time it was clear for me to have best of both worlds right from the start. Gaining advantage from DAW based sequencing, mixing and mastering – speaking in terms of precision, affordability and total recall – but also the fun and hands-on experience just real outboard gear can give you and I’m not talking about cheap plastic controllers here (don’t get me started on that one).

For the DAW itself I just reactivated my rather aged PC based workstation which complained to need some hundred or so updates but then afterwards actually performed quite smoothly again. The whole installation is much more lean now and I did not included all that sh*tload of huge sample libraries just as an example. For the time being, I can live with its constraints and can focus on other and more important stuff now. Also, there won’t be a mixing desk anymore and I just added some more converters to my old but trusty RME card via ADAT. Nice to see the old standards still working flawless. Now the fun part begins: connecting all the stuff.

To be continued.

happy new year …

… I wish to all of you!
Herbert